Eurobodalla Integrated Water Cycle
Management Strategy
Eurobodalla Integrated Water Cycle Management Strategy
Foreword
This Integrated Water Cycle Management (IWCM) strategy, the State’s first pilot project,
has been prepared by NSW Department of Public Works and Services (DPWS) using the
IWCM process developed by NSW Department of Land and Water Conservation, Town
Water Treatment and Recycling Unit. This study has demonstrated that the IWCM process
delivers significant environmental, social and economic benefits compared to the traditional
approach.
DPWS acknowledges the significant contribution made by the DLWC project team in
particular Peter Schneider, Peter Ledwos, Adrian Langdon, Russell Beatty, Annette Davison
and Emma Pryor.
DPWS also acknowledges the significant contribution made by the Eurobodalla Shire
Council project team led by Angus McLean and Mark Hankinson.
The core DPWS project team involved in the preparation of the Eurobodalla IWCM Strategy
included:
!
Roshan Iyadurai
!
Annalisa Contos
!
Ross Bailey (Project Manager)
The DPWS core project team was supported by the following DPWS staff:
!
Garth Dickinson
!
Vu Dao
!
Lara Hess
!
Col Nalty
!
Jenny Reid (Publications)
!
John Anderson (Reviewer)
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Eurobodalla Integrated Water Cycle Management Strategy
Executive Summary
Water is a precious natural resource essential for the maintenance of ecosystems and all human
activities. The degradation of our rivers, groundwaters and estuaries provides clear evidence that
NSW water resources are under stress. New water legislation has been introduced to protect water
for present and future generations. Integrated water cycle management is an innovative way of
managing urban water for local water utilities, which incorporates all components of urban water
services. The aim is to achieve optimum water use to reduce the human impacts on water
resources.
Introduction
Integrated water cycle management (IWCM) is an innovative way of managing the urban
water services for local water utilities. IWCM aims to combine all aspects of water
management and treat the system as an interacting whole, whereas traditional water
management looks at each component of the urban water system (water supply, sewerage,
stormwater) in isolation. With IWCM, water use is optimised while minimising impacts to the
environment and other water users.
IWCM is based on three simple questions:
!
What is the problem? relates to water cycle management impacts (or perceived
impacts) as well as water management problems. To answer this question
necessitates an understanding of the catchment in order to set a benchmark on the
resource needs and availability.
!
How do we fix the problem? looks at addressing water management problems
and requires an understanding of State Government water reform policies, which
describe key water management issues and the appropriate management
responses to them. Since there is more than one management option, a balanced
outcome planning examining the triple bottom line (TBL) of social, environmental
and financial bottom line is used to select the best overall option.
!
The last question, How do we know the problem is fixed? is the process by
which we confirm that all impacts are managed to the desired level, and water use
is optimised using social, economic and environmental objectives.
The structure of this report is based on answering these three fundamental questions. Part
A and Part B of the report deal with the first of these questions by identifying the issues
affecting Eurobodalla’s water services. Parts C and D then look at how the issues identified
in the first parts of the report can be managed. Finally, Part E looks at identifying measures
to ensure that the problems are fixed.
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Eurobodalla Integrated Water Cycle Management Strategy
What are the Issues?
The NSW water reforms aim to achieve a better balance between water use and environmental
protection through setting environmental objectives for all NSW rivers which will cover river flow and
water quality objectives.
Water-sharing plans are being developed to protect our rivers, which become particularly vulnerable
during low flow periods.
Eurobodalla Shire Council’s (ESC) water supply, sewerage and stormwater infrastructure
requires upgrading to meet population growth and legislative standards. Developing an
IWCM strategy is a structured process designed to evaluate integrated water management
opportunities within individual towns and the Shire as a whole. Thus the IWCM strategy
developed in this report details the Eurobodalla community and Council’s vision to manage
urban water services within the local catchment context.
The broad IWCM strategy objectives are to achieve more efficient water use, to reduce
environmental impacts from water diversions, urban drainage and treated wastewater
discharges, and to reduce long term costs of water services for Eurobodalla Shire residents
and businesses. Some of the specific issues impacting upon Eurobodalla’s water services
are listed below.
!
Water Reforms
!
Pricing Reforms
!
Legislative Compliance Responsibilities
!
Catchment Management Issues
!
Urban Planning Issues - the Shire’s population is projected to grow from 33 100 in
2001 to about 47 500 in 2031
!
Urban Water Management Issues:
−
Urban Water Use
Analysis indicates that the Shire’s annual urban water needs will increase
from the current rate of 5 300 ML/a to 7 000 ML/a in the next three decades
if current water use practices and trends continue.
−
Urban Water Discharges
In the next three decades the wastewater flows are expected to increase by
30% from 4 500 ML/a to 5 850 ML/a. On-site systems account for around
15% of wastewater produced in urban areas of Eurobodalla. Approximately
85% (3 820 ML/a) receives secondary treatment at one of the Council’s five
STPs.
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Eurobodalla Integrated Water Cycle Management Strategy
How Do We Fix the Issues
!
The need for new infrastructure can be reduced or delayed by using a variety of IWCM
tools.
!
Important components of the Shire wide scenarios are expanded demand management
programs, introduction of rainwater tanks and better management or enhancement of onsite wastewater systems.
!
Regional water supply infrastructure requirements include additional delivery capacity,
water filtration and additional future water storage.
!
Improvements can be made to the reticulated sewerage schemes and the management of
on-site systems to reduce the impacts on environmental water quality.
!
Water efficiency can be further improved through the development of a number of new
water reuse schemes.
!
The new infrastructure options can be combined with IWCM measures to produce
integrated Shire-wide scenarios to optimise social, environmental and financial outcomes.
Regional Water Supply Management Strategy
Opportunities for Managing Regional Water Demand
Eurobodalla has made significant gains in water conservation and demand reduction
through the ‘user pays’ pricing policy and community awareness programs. Achieving more
sustainable water use involves a multi-faceted approach. There are a variety of IWCM tools
available to reduce water demands and achieve more sustainable outcomes at the regional
level. Fact sheets of IWCM tools can be found in Section 4 of the report. How these can be
applied for Eurobodalla is found in Section 8.1. The triple bottom line (TBL) assessment
carried out on all the demand side opportunities, has bundled planning controls,
unaccounted for water assessment and loss reduction program, water pricing, water
conservation education program targeting outdoor watering use and non-residential water
use and an active showerhead retrofit program as the main elements of a comprehensive
demand management program.
Opportunities for Developing the Local Supply Sources
Three rainwater tank opportunities were identified as local supply sources.
1.
Rainwater tanks in all new developments
2.
Rainwater tanks in all new developments and 20% of existing developments
3.
Rainwater tanks in all new developments and 40% of existing developments.
According to the TBL assessment, options 2 and 3 ranked as equally suitable options in
terms of environmental, social and financial criteria. Whilst the option of mandating
rainwater tanks in all new developments and retrofitting 40% of existing developments
achieves the best environmental outcomes, it is the most expensive option in terms of
community costs. Water savings through mandating rainwater tanks in all new
developments plus retrofitting 20% of existing houses has been included in the integrated
regional supply options. Other potential local supply source opportunities include
stormwater reuse and residential greywater reuse.
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Eurobodalla Integrated Water Cycle Management Strategy
Opportunities for Developing Regional Supply Sources
The existing supply infrastructure, limited only by the current extraction license, is adequate
to meet demands for the next 50 years or more. However, the system operates below
design optimum due to operational constraints, the main one being the limitation on
pumping water during turbid river conditions. In addition, Council has elected not to pump
during periods of low flow due to environmental concerns for the health of the river. This
has required Council to enforce water restrictions at a greater frequency than the system
design. Immediate, short- and long term measures have been identified to improve the
system reliability.
Immediate Infrastructure Measures
!
Relocation of the Malua Bay booster pumps to Mossy Point
!
Upgrading of power supply to Moruya River pumps
!
Installation of pumps or variable speed drives to overcome the flow mismatch
between the low and high level pumps at Tuross River intake
!
Improved telemetry and control elements on reservoirs and valves
!
Provision of rechlorination facilities at strategic locations
Short term measures. These include the ability to harvest higher river flows, the ability to
transfer and store water quickly in Deep Creek Dam, and measures to reduce demands.
The works would include:
!
A dedicated pipeline between Moruya River intake and Deep Creek Dam
!
Filtration of the water supplied to the consumers
Long term measures. The main long term measure includes the provision of additional
water storage to maintain supplies during drought periods. The drought storage could be
provided by enlarging the existing Deep Creek Dam, by providing a new off-river storage in
the central or southern area of the Shire or through desalination.
Supply Opportunities
Four regional supply opportunities have been examined. Each incorporates the immediate
and short term measures but consider different long term options. The secure yield of the
system is based on protection of low river flows. In the short term an initial environmental
flow regime (95/30 flow rule) with a more conservative environmental flow (80/30 flow rule)
being introduced in 2020. An explanation of the environmental flow regimes is located in
Section 6.1.1.
Opportunity 1. - Enlarge Deep Creek Dam. The present value per ML of yield is $7.70 $9.50.
Opportunity 2. - New Southern off-river storage filled from high flows in the Tuross River.
The present value per ML of yield is $8.70.
Opportunity 3. - Central off-river storage built on Barretts Creek and supplied by high flows
in the Moruya River. Water extraction from the Tuross River would cease. The present
value per ML of yield is $12.60.
Opportunity 4. Desalination of seawater. The present value per ML of yield is $8.10.
A triple bottom line (TBL) assessment indicates that opportunity 2, a new Southern dam,
presents the best future supply for Eurobodalla. The dam would be built when required
(subject to future reviews and population growth). This is the preferred supply opportunity
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Eurobodalla Integrated Water Cycle Management Strategy
as it reduces the risk to supply of algal blooms as well as reducing the risk of loss of supply
in the South of the shire due to pipeline breaks (see section 8.3).
Opportunities for Reclaimed Water
Eurobodalla Shire Council reclaims the sewage effluent to achieve environmental and
social benefits where it is economically viable and socially acceptable. Currently about 5%
of the Shire’s effluent is reused at Batemans Bay and Moruya Golf Courses. An additional
5% of this is used in the sporting fields at Moruya Reclaimed water is also proposed to be
made available for agricultural and industrial reuse in conjunction with sewering the North
Moruya Industrial Estate. The IWCM strategy has identified a number of additional
reclaimed water opportunities within the Shire, and these are presented in Section 8.3. The
generally high rainfall and seasonal nature of the NSW south coast climate limits reuse
opportunities to mainly the dry season in late spring and early summer. Thus, practical
reuse strategies should aim to reuse a high percentage of dry weather flows. If all
opportunities listed below were to be implemented, it would result in excess of 60%
beneficial reuse of dry weather flows in the Shire. The proposed opportunities include:
!
A possible residential reuse system for the Rosedale development. The system
would feature a water reclamation plant at Tomakin and a reticulation system
specifically constructed for the delivery of reclaimed water for garden irrigation,
toilet flushing and potentially for washing machines use.
!
Supplying the dairy farm area around Moruya River with reclaimed water produced
from the STPs located north of Moruya (referred to as the Northern scheme).
!
Supplying the agricultural area near Bodalla with reclaimed water from both the
Bingie and Narooma STP’s (referred to as Southern Scheme).
!
Local reuse for irrigation for example on golf courses and parks.
!
There is potential to use reclaimed water from the northern reuse scheme to meet
environmental flow needs in the Moruya River. The reclaimed water used for
environmental flow substitution would be treated to a high standard to be
acceptable for this purpose. This would allow Council to extract additional water
during low flow periods to supply to the community. The viability and sustainability
of this opportunity needs further investigation.
!
Recharging the groundwater aquifer around Broulee and South Durras for
subsequent removal by residents for external and toilet use. The viability and
sustainability of this opportunity needs further investigation.
Integrated Options
Traditionally, water utilities have focused on developing greater supply sources to meet the
growing water needs and community expectations. With the emphasis on maintaining
reliable water supplies, little consideration has been given to the environment. Having
identified the various water resource opportunities, the next step involves bundling the
opportunities to form integrated options. The selected regional water supply option,
opportunity 2, was bundled together with the various reuse and recycling options to form
integrated options. These are discussed in Section 8.5. These integrated scenarios form
the basis of the Shire-wide scenarios (Section 10).
Local Water Strategies
IWCM options have been proposed for 15 towns and villages in the Eurobodalla Shire to
address the local landscape, water services and community issues. A summary of the
recommended integrated options for each town is given in the following table.
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Eurobodalla Integrated Water Cycle Management Strategy
Town
Integrated Option
South Durras
Harvested roof water supplemented with reticulated water from a local
supply source and enhanced management of existing on-site facilities
Nelligen
Harvested roof water supplemented with reticulated water from the regional
scheme and the provision of reticulated sewerage system with transfer to
the Batemans Bay system and greywater reuse
Batemans Bay
Transfer of southern catchment sewage to Tomakin STP, upgrade
Batemans Bay STP and transport system, stormwater quantity and quality
control in high and low priority catchments and open space reuse
Rosedale and Guerilla Bay
Provision of reticulated sewerage system with sewage transferred to
Tomakin system with greywater reuse of suitable systems and rainwater
harvesting utilising disinfected tanks
Tomakin and Surrounds
Improved management of the existing sewerage system, optimisation of the
treatment plant to handle increased loads in the future from both the local
area and Southern Batemans Bay, disinfection of the effluent and
stormwater quantity and quality control in high and low priority catchments.
Moruya and Moruya Heads
Improved management of the existing sewerage system, reuse of effluent
on open spaces and in the proposed industrial development and stormwater
quantity and quality control in high and low priority catchments.
Congo
Improved management of existing water supply and enhanced management
of existing on-site facilities.
Tuross Heads
Improved management of the existing sewerage system, disinfection of the
effluent and effluent reuse on golf course.
Bodalla
Provision of reticulated sewerage system with sewage treatment using a
package treatment plant. Greywater reuse by suitable systems and
rainwater harvesting utilising disinfected septic tanks
Potato Point
Provision of reticulated sewerage system, transfer to Bodalla system with
greywater reuse and rainwater harvesting
Dalmeny, Kianga and Narooma
Improved management of the existing sewerage system, optimisation of the
treatment plant to handle increased loads in the future, disinfection of the
effluent, reuse of effluent on open spaces and stormwater quantity and
quality control in high and low priority catchments.
Mystery Bay
Enhanced management of existing on-site facilities
Central Tilba and Tilba Tilba
Centralised management of effluent from on-site facilities with agricultural
reuse
Akolele
To be sewered in conjunction with Wallaga Lake Heights
The TBL assessments show that with the increased use of IWCM solutions, additional
benefits accumulate, resulting in lower overall costs, and improved social and
environmental outcomes.
Shire-wide Water Cycle Management Scenarios
The following Shire-wide scenarios have been based on the regional integrated options,
and have taken into account the individual local water strategies. They are
recommendations and may be modified to reflect the priorities and preferences of individual
communities.
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Eurobodalla Integrated Water Cycle Management Strategy
Shire-Wide Scenarios
Scenario
Description
Waterwise education
Provision of reticulated water for high priority villages
Provision of reticulated water for low priority villages
Agricultural reuse
Traditional Solution
NPV $198.5 M
Southern dam capacity 5 600 ML
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and enhance
existing Tomakin STP capacity, upgrade Batemans Bay transport systems and STP
Enhance the existing Narooma STP capacity when load meets capacity
Improved management of urban stormwater in high priority catchments
Provision of reticulated sewerage for high and low priority villages
Comprehensive demand management
Southern dam capacity 1 500 ML
Integrated Scenario 1
NPV $90.2 M
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and enhance
existing Tomakin STP capacity, upgrade Batemans Bay transport systems and STP
Enhance the existing Narooma STP capacity when load meets capacity
Enhanced management of on-site systems
Comprehensive demand management and water sensitive urban design
10 kL rainwater tanks for all new developments and in 20% of existing houses
Southern dam capacity 900 ML
Integrated Scenario 2
NPV $103.9 M
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and enhance
existing Tomakin STP capacity, upgrade Batemans Bay transport systems and STP
Enhance the existing Narooma STP capacity when load meets capacity
Provision of reticulated sewerage for high priority villages
Enhanced management of on-site systems
Comprehensive demand management and water sensitive urban design
10 kL rainwater tanks for all new developments and 20% of existing houses
Provision of reticulated water supply to high priority villages
Integrated Scenario 3
NPV $105.5 M
Southern dam capacity 930 ML
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and enhance
existing Tomakin STP capacity, upgrade Batemans Bay transport systems and STP
Enhance the existing Narooma STP capacity when load meets capacity
Reticulated sewerage for high priority villages
Enhanced management of on-site systems
Comprehensive demand management and water sensitive urban design
10 kL rainwater tanks for all new developments and 20% of existing houses
Provision of reticulated water supply to high and low priority villages
Integrated Scenario 4
NPV $108.2 M
Southern dam capacity 1 010 ML
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and enhance
existing Tomakin STP capacity, upgrade Batemans Bay transport systems and STP
Enhance the existing Narooma STP capacity when load meets capacity
Provision of reticulated sewerage for high and low priority villages
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Eurobodalla Integrated Water Cycle Management Strategy
Scenario
Description
Comprehensive demand management and water sensitive urban design
10 kL rainwater tanks for all new developments and 20% of existing houses
Provision of reticulated water supply to high and low priority villages
Reclaimed water reuse for agriculture
Integrated Scenario 5
NPV $126.2 M
Southern dam capacity 1 010 ML
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and
enhance existing Tomakin STP capacity, upgrade Batemans Bay transport
systems and STP
Enhance the existing Narooma STP capacity when load meets capacity
Improved management of urban stormwater in high priority catchments
Provision of reticulated sewerage for high and low priority villages
Comprehensive demand management and water sensitive urban design
10 kL rainwater tanks for all new developments and 20% of existing houses
Provision of reticulated water supply to high and low priority villages
Reclaimed water reuse for agriculture
Reclaimed water reuse for aquifer recharge for subsequent non-potable water use
Integrated Scenario 6
NPV $126.7 M
Reclaimed water reuse for non-potable water use in new developments (dual
reticulation)
Southern dam capacity 840ML
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and
enhance existing Tomakin STP capacity, upgrade Batemans Bay transport
systems and STP
Enhance the existing Narooma STP capacity when load meets capacity
Improved management of urban stormwater in high priority catchments
Provision of reticulated sewage for high and low priority villages
Comprehensive demand management and water sensitive urban design
10kL rainwater tank for all new developments and 20% of existing houses
Provision of reticulated water supply to high and low priority villages
Reclaimed water reuse for agriculture
Reclaimed water reuse for aquifer recharge for subsequent non-potable water use
Integrated Scenario 7
NPV $123.7 M
Reclaimed water for non-potable water use in new developments (dual
reticulation)
Reclaimed water reuse for environmental flow substitution
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and
enhance existing Tomakin STP capacity, upgrade Batemans Bay transport
systems and STP
Enhance the existing Narooma STP capacity when load meets capacity
Improved management of urban stormwater in high and low priority catchments
Provision of reticulated sewage for high and low priority villages
Southern dam needed between 2035 and 2040
The TBL assessment table below provides the comparative environmental, social and
economic perspective of each water cycle management scenario.
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Eurobodalla Integrated Water Cycle Management Strategy
Integrated Scenarios
6 + EF
Substitution
7
DM + RWT
+ agri. +
reuse + pot.
6
DM + RWT
+ Agri.
5
DM + RWT
4
DM + RWT
3
DM + RWT
2
DM
1
Traditional
0
Ensure the efficient use of the fresh water
resource
0
1
2
2
2
3
3
3
Minimises water extractions and protects
low flows
0
1
2
2
2
3
3
3
Minimises green house gas emissions
3
3
3
2
2
1
1
1
Minimises pollutants being discharged to the
aquatic environment
1
1
1
1
1
2
2
3
Minimises urban stormwater volumes
0
0
1
1
2
2
2
3
Ensure sustainable practices
0
1
2
2
2
3
3
3
Environmental Sum
4
7
11
10
11
14
14
16
Environmental Rank
8
7
4
6
4
2
2
1
0
1
2
2
2
3
3
3
ENVIRONMENTAL
SOCIAL
Improves security of town water supply
Improves the quality of drinking water
0
0
0
2
3
3
3
3
Improves urban water service levels
1
1
2
2
3
3
3
3
Increase public awareness of urban water
issues
1
2
3
3
3
3
3
3
Minimises non-compliance to legislation
3
3
3
3
3
3
3
3
Protects public health
2
2
2
3
3
3
3
3
Social Sum
7
9
12
15
17
18
18
18
Social Rank
8
7
6
5
4
1
1
1
Water Supply
110.3
64.2
73.1
74.7
76.8
76.8
77.3
71.2
Sewerage
79.7
26.1
30.7
30.7
31.4
40.8
40.8
40.8
Stormwater
8.5
0
0
0
0
8.5
8.5
11.7
103.8
105.
4
126.6
123.
7
ECONOMIC
NPV @ 7% in $m
Sub-total
198.5
Change in the typical
residential rate bill from
the traditional scenario
108.2
126.1
Water Supply
0
-124
-144
-137
-128
-128
-122
-149
Sewerage
0
-192
-186
-186
-181
-145
-145
-145
Stormwater
0
Financial Rank
8
1
2
3
4
6
7
5
TBL Sum
24
15
12
14
12
9
10
7
TBL Rank
Savings from
Traditional Case
(NPV @ 7%)
x
90.3
8
7
4
6
4
2
3
1
Water Supply
0
46.1
37.2
35.6
33.5
33.5
32.9
39.1
Sewerage
0
53.6
49.0
49.0
48.3
38.9
38.9
38.9
Stormwater
0
-
-
-
-
0
0
+3.2
Eurobodalla Integrated Water Cycle Management Strategy
How Do We Know the Issues Are Fixed?
Eurobodalla’s integrated water cycle management strategy offers significant environmental, social
and economic benefits.
The overall result of the IWCM process for Eurobodalla is better environmental and social
outcomes at a lower cost. The outcomes of the strategy provide a baseline against which
to benchmark future reviews and ESC's journey towards achieving sustainable integrated
water cycle management. The identified outcomes include:
Environmental Outcomes
!
A reduction in the amount of water drawn for urban supply from the Shire’s rivers
through demand management measures and use of rainwater tanks.
!
Better protection of low flows and preservation of natural flow patterns leading to
improved environmental water quality and improved aquatic habitat conditions.
!
A reduction in future water storage requirements needed to provide the higher level
of low-flow protection.
!
Reduced pollution of the waterways and coastal lakes through improved
wastewater and stormwater management, source control, sewage pump station
and treatment plant upgrades.
!
Reduced effluent discharges to waterways through the reductions in urban water
use, stormwater inflow and groundwater infiltration, and the development of water
reuse systems, leading to improved recreational water quality.
!
Improved management of existing on-site wastewater systems in the villages
resulting in lower environmental public health risk and improved sustainability of
local aquifers.
!
Reduces greenhouse gas emissions and energy consumption.
!
Streamlined subsequent environmental impact assessments, reducing study times
and costs.
Social Outcomes
!
Improved drought security and reliability of supply through increased delivery
capacity and faster refilling of the Deep Creek storage.
!
Improved water quality and public health protection for regional water supply
consumers through the construction of water filtration plants.
!
Existing deficiencies in the levels of service to consumers are addressed.
!
In one integrated option there is an opportunity for further savings by deferring the
need for a Southern dam beyond the adopted 30 year planning horizon by using
reclaimed water to meet environmental flow needs.
!
Provision of backyard supply sources (rainwater tanks) provide customers with
supply source choice and an appreciation of their water use pattern resulting in
lower water use in the long term.
!
The comprehensive demand management program in addition to delivering savings
in water bills will also result in electricity savings.
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Eurobodalla Integrated Water Cycle Management Strategy
!
Integrated solutions that closely match community wants and expectations.
Economic Outcomes
The savings have been achieved due to the application of the IWCM process that enabled
scheme components to be ‘right’ sized and optimised. From the table it could be seen that
the greater the integration of the water sources the greater the economic saving with higher
environmental and social outcomes
The recommended scenario, Scenario 5, is 36% cheaper in terms of present value than the
tradition solution (Section 10). It results in a saving of $273 in a typical rate bill compared
with the traditional option Moreover the integrated scenarios deliver significantly more
environmental, social and resource sustainability benefits.
To realise and sustain these outcomes Council requires both physical assets and nonstructural solutions. The non-structural solutions include:
!
Coordinated data and asset management systems
!
Common water fund and appropriate pricing policies
!
Environmental, OH&S and public health monitoring programs and systems
Although this strategy has been developed for a planning period of 30 years, the strategy
review cycle should be every 5 years and not greater than 10 years.
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Eurobodalla Integrated Water Cycle Management Strategy
Table Of Contents
1
INTRODUCTION
1.1
Overview
1.1.1 The Integrated Water Cycle Management Process
1.1.2 Balanced Outcomes Planning
1.1.3 Principles of Integrated Water Cycle Management
1.1.4 Objectives of Integrated Water Cycle Management
Strategy
1.2
The Water Cycle
1.2.1 The Natural Water Cycle
1.2.2 The Human Water Cycle
1.2.3 Integrated Water Cycle Management
1.3
Background to Eurobodalla Shire’s Integrated Water Cycle
Management Strategy
1.4
Eurobodalla Shire’s Progress So Far
1.5
Where To From Here?
PART A WHERE DO WE WANT TO BE?
1
1
1
1
2
2
3
3
4
5
5
6
6
7
2
STRATEGIC BUSINESS OBJECTIVES
2.1
Overview
2.2
The Business Objectives
9
9
10
3
COMMUNITY WANTS, NEEDS AND FEEDBACK
3.1
Community Wants and Needs Identification
3.1.1 Environmental Values in Relation to Urban Waters
3.1.2 Urban Development
3.1.3 Issues for Future Development of Urban Water
Services
3.1.4 Options to be Considered in the IWCM Strategy
3.1.5 Community Preferences
3.2
Community Feedback
13
13
13
13
4
INTEGRATED WATER CYCLE MANAGEMENT TOOLS
4.1
Overview
15
15
5
INTEGRATED WATER CYCLE MANAGEMENT OPTIONS
ASSESSMENT CRITERIA
5.1
Overview
5.2
The Assessment Criteria
27
27
27
13
13
14
14
PART B WHAT ARE THE ISSUES?
29
6
31
31
WHAT ARE EUROBODALLA’S ISSUES?
6.1
Government Initiated Reform Compliance Issues
6.1.1 Water Reforms and the Water Management Act
2000
6.1.2 Pricing Reforms
6.1.3 Legislative Compliance issues
6.2
Catchment Issues
6.2.1 Environmental Issues
6.2.2 Water Quality Issues
6.3
Urban Planning Issues
6.3.1 Population Distribution
6.3.2 Shire-wide Population Growth
31
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37
37
38
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Eurobodalla Integrated Water Cycle Management Strategy
6.4
6.5
40
40
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43
43
43
44
47
51
51
57
58
PART C HOW DO WE FIX THE ISSUES
59
7
PART C INTRODUCTION
61
8
REGIONAL WATER CYCLE MANAGEMENT OPPORTUNITIES
8.1
Opportunities for Managing the Regional Water Demands
8.1.1 Status of Current Measures
8.1.2 Introduction
8.1.3 Planning Controls
8.1.4 Water Conservation Education
8.1.5 Residential Water Efficiency Program
8.1.6 Non-residential Water Efficiency Program
8.1.7 Unaccounted for Water Assessment and Loss
Reduction
8.1.8 Water Pricing Opportunity
8.1.9 Water Waste Ordinance Opportunity
8.1.10 Comprehensive demand management program
8.2
Opportunities for Developing the Local Supply Sources
8.2.1 Roof Water Harvesting
8.2.2 Stormwater Harvesting
8.2.3 Residential Greywater Reuse
8.2.4 Benefits of Utilising Local Water Sources
8.3
Opportunities for Developing the Regional Supply Sources
8.3.1 General Overview
8.3.2 Immediate Measures
8.3.3 Short term Measures
8.3.4 Long term Regional Supply Opportunities
8.4
Opportunities for Reclaimed Water Use
8.4.1 Project Initiatives
8.4.2 Reclaimed Water Volumes
8.4.3 Reclaimed Water Use
8.5
Regional Integrated Water Cycle Management Options
8.5.1 Overview
8.5.2 Description of the Regional Water Supply
Integrated Options
63
63
63
63
64
65
68
69
LOCAL WATER MANAGEMENT OPPORTUNITIES
9.1
Introduction
9.2
South Durras
9.2.1 Background
9.2.2 What Are the Issues?
9.2.3 How Do We Fix the Problems?
9.2.4 Integrated Water Cycle Management Scenarios
9.3
Nelligen
9.3.1 Background
9.3.2 What are the Issues
105
105
106
106
107
108
114
117
117
118
9
xiv
6.3.3 Population Served With Council Water Services
6.3.4 Shire-wide Housing
6.3.5 Residential Growth
6.3.6 Data Accuracy
6.3.7 Tourist Impacts
Urban Water Management Issues
6.4.1 Urban Water Use and Discharge – Past and
Present
6.4.2 Urban Water Use and Discharge – Future
Predictions
Infrastructure Performance Issues
6.5.1 The Regional Water Supply
6.5.2 Sewage Treatment Issues
6.5.3 Stormwater Issues
70
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78
82
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85
90
91
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91
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Eurobodalla Integrated Water Cycle Management Strategy
9.4
9.5
9.6
9.7
9.8
9.9
9.10
9.11
9.12
9.13
9.14
9.15
9.3.3 How Do We Fix the Problems
9.3.4 Integrated Water Cycle Management Scenarios
Batemans Bay and Surrounds
9.4.1 Background
9.4.2 What Are the Issues?
9.4.3 How Do We Fix These Issues?
9.4.4 Integrated Water Cycle Management Scenarios
Mogo
9.5.1 Background
9.5.2 What Are the Issues?
9.5.3 How Do We Fix the Problems?
Rosedale and Guerilla Bay
9.6.1 Background
9.6.2 What Are The Issues
9.6.3 How Do We Fix The Problems
9.6.4 Integrated Water Cycle Management Scenarios for
Rosedale and Guerilla Bay
9.6.5 Triple Bottom Line Assessment for Rosedale and
Guerilla Bay
Tomakin and Surrounds
9.7.1 Background
9.7.2 What Are the Issues?
9.7.3 How Do We Fix these Issues?
9.7.4 Integrated Water Cycle Management Scenarios
Moruya and Moruya Heads
9.8.1 Background
9.8.2 What Are the Issues?
9.8.3 How Do We Fix These Issues?
Congo
9.9.1 Background
9.9.2 What Are the Issues?
9.9.3 How Do We Fix the Problems?
Bodalla
9.10.1 Background
9.10.2 What Are the Issues
9.10.3 How Do We Fix the Problems?
9.10.4 Integrated Water Cycle Management Scenarios
9.10.5 Triple Bottom Line Assessment
Potato Point
9.11.1 Background
9.11.2 What Are the Issues?
9.11.3 How Do We Fix the Problems
9.11.4 Integrated Water Cycle Management Scenarios
Dalmeny Kianga and Narooma
9.12.1 Background
9.12.2 What Are the Issues?
9.12.3 How Do We Fix these Issues?
9.12.4 Integrated Water Cycle Management Scenarios
Mystery Bay
9.13.1 Background
9.13.2 What Are the Issues?
9.13.3 How Do We Fix The Problems?
9.13.4 Integrated Water Cycle Management Scenarios
Central Tilba and Tilba Tilba
9.14.1 Background
9.14.2 What are the Issues?
9.14.3 How Do We Fix the Problems?
9.14.4 Integrated Water Cycle Management Scenarios
Akolele
9.15.1 Background
9.15.2 What Are the Issues?
119
124
127
127
129
132
137
140
140
141
141
142
142
143
144
149
150
151
151
153
155
157
159
159
160
161
165
165
166
166
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171
172
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191
193
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Eurobodalla Integrated Water Cycle Management Strategy
9.15.3 How Do We Fix the Problems?
10
xvi
SHIRE WIDE INTEGRATED WATER CYCLE MANAGEMENT
SCENARIOS
10.1
Overview
10.2
Scenario Building
10.2.1 Description of the Shire wide Water Cycle
Management Scenarios
10.3
Assessment of Integrated Water Cycle Management
Scenarios
208
209
209
210
212
219
PART D HOW TO DELIVER THE SCENARIOS
223
11
TIMEFRAME FOR SCENARIO IMPLEMENTATION
225
12
MANAGEMENT AND PROCUREMENT METHODS
12.1
Management Methods
12.2
Procurement Methods
235
235
236
PART E HOW DO WE KNOW THE ISSUES ARE FIXED?
237
13
OVERVIEW
13.1
Study Outcomes
13.1.1 Economic Outcomes
13.1.2 Environmental Outcomes
13.1.3 Social Outcomes
13.2
How to Realise and Sustain the Outcomes
13.3
Strategy Review Cycle
239
239
239
240
241
241
242
14
BIBLIOGRAPHY
243
Eurobodalla Integrated Water Cycle Management Strategy
APPENDICIES
A
Strategic Business Objectives
B
Community Workshop Outcomes
C
Coarse Screening
D
Acceptable Water Quality and Treatment Requirements for End Uses
E
Developing Growth Rates and Demand at a Water Reservoir Level
F
Details of Existing Regional Water Supply Infrastructure
G
Yield Analysis (Separate Volumes x 3)
H
Water Treatment Processes
I
Distribution Requirement Assessment
J
Moruya River to Deep Creek Dam Pipeline Size and Rough Selection
Assessment
K
Dam Site Selection and Engineering Assessment (Separate Volume)
L
Regional Water Supply Opportunities: Summary of Costs
M
Desalination
N1
Regional Reuse Scheme Cost Estimate
N2
Fact Sheet on Hydroponic Enterprises
O
Regional Water Supply Integrated Options: Costs and Present Value
Estimates
P
Description of Village Sewerage Management Systems
Q
Cost Estimate and NPV for Batemans Bay Sewerage Treatment
Opportunities
R
Eurobodalla Shire Sewerage Costs for Existing Town Systems
S
Cost Estimates for Villages Water Supply and Sewerage
T
Cost Estimates for Shire Wide Scenarios
U
IWCM Financial Plans
V
Current Education Initiatives
W
Urban Stormwater Issues, Management and Opportunities
(Separate Volume)
X
Small Town Risk Assessment
Y
The Impact of Connecting Residents to Trunk Mains
Z
Rainwater Tanks
xvii
Eurobodalla Integrated Water Cycle Management Strategy
TABLES
xviii
Table 3-1 Community Expectations
14
Table 5-1 IWCM Assessment Criteria
28
Table 6-1 Population Projection
39
Table 6-2 Internal and External Water Use by Dwelling Type
45
Table 8-1 Annual Unaccounted-for Water Figures From 1995 to 2001
71
Table 8-2 Triple Bottom Line Assessment for Regional Water Demand
Opportunities
75
Table 8-3 Percentage of Total Regional Demand That Can Be Supplied
Through Rainwater Tanks (With No Other Demand Measures)
79
Table 8-4 Proposed Rebates For Rainwater Tank Installation
79
Table 8-5 Single Household Cost to Rainwater Tank With Council Rebate
80
Table 8-6 Total Yearly Community Costs for Rainwater Tanks Installation
(including rebate)
80
Table 8-7 Triple Bottom Line Assessment for the Regional Rainwater Tanks
Opportunities
81
Table 8-8 Scheme Estimates of Long Term Regional Supply Opportunities
85
Table 8-9 Social and Environmental Aspects – Long term Supply Opportunities
87
Table 8-10 Triple Bottom Line Assessment of Regional Water Supply
Opportunities
88
Table 8-11 Comparative Costs for Stand Alone Supply Demand Sensitivities
90
Table 8-12 Reclaimed Water Volume Projections
91
Table 8-13 Costs for the Regional Reclaimed Water Scheme
98
Table 8-14 Regional Water Supply Integrated Options
99
Table 8-15 TBL Assessment for the Regional Water Supply Options
104
Table 9-1 Integrated Water Cycle Management Opportunities for South Durras
110
Table 9-2 Social and Environmental Aspects of the Medium to Long Term
Opportunities for South Durras
113
Table 9-3 Integrated Scenarios for South Durras
115
Table 9-4 Triple Bottom Line Reporting for South Durras
116
Table 9-5 Integrated Water Cycle Management Opportunities for Nelligen
120
Table 9-6 Social and Environmental Aspects of the Medium to Long Term
Opportunities for Nelligen
123
Table 9-7 Integrated Scenarios for Nelligen
125
Table 9-8 Triple Bottom Line Assessment for Nelligen
126
Table 9-9 Current and Future Peak Day Demands for Batemans Bay
131
Table 9-10 Medium to Long term Water Cycle Management Opportunities for
Batemans Bay
134
Table 9-11 Social, Financial and Environmental Aspects of the Sewage
Management Options for Batemans Bay
136
Table 9-12 Triple Bottom Line Assessment of the Sewage Management of the
Water Cycle in Batemans Bay
137
Table 9-13 Integrated Water Cycle Management Scenarios for Batemans Bay
138
Eurobodalla Integrated Water Cycle Management Strategy
Table 9-14 Triple Bottom Line Reporting for Batemans Bay
139
Table 9-15 Integrated Water Cycle Management Opportunities for Rosedale
and Guerilla Bay
145
Table 9-16 Social and Environmental Aspects of the Medium to Long term
Opportunities for Rosedale and Guerilla Bay
147
Table 9-17Integrated Water Cycle Management Scenarios for Rosedale and
Guerilla Bay
149
Table 9-18 Triple Bottom Line Assessment for Rosedale and Guerilla Bay
150
Table 9-19 Current and Future Average and Peak Day Demands for Tomakin
152
Table 9-20 Costing of Management Opportunities in Tomakin and Surrounds
156
Table 9-21 Integrated Water Cycle Management Scenarios for Tomakin and
Surrounds
157
Table 9-22 Triple Bottom Reporting for Tomakin and Surrounds
158
Table 9-23 Costing of Management Opportunities for Moruya and Moruya
Heads
162
Table 9-24 Integrated Water Cycle Management Scenarios for Moruya and
Moruya Heads
163
Table 9-25 Triple Bottom Line Reporting for Moruya and Moruya Heads
164
Table 9-26 Costs of Opportunities for Congo
168
Table 9-27 Integrated Water Cycle Management Opportunities for Bodalla
174
Table 9-28 Social and Environmental Aspects of the Medium to Long Term
Opportunities for Bodalla
175
Table 9-29 – Integrated Water Cycle Management Strategies for Bodalla
176
Table 9-30 Triple Bottom Line Assessment for Bodalla
177
Table 9-31 Integrated Water Cycle Management Opportunities for Potato Point
180
Table 9-32 Social and Environmental Aspects of the Medium to Long Term
Opportunities for Potato Point
183
Table 9-33 Integrated Scenarios for Potato Point
184
Table 9-34 Triple Bottom Line Assessment of Scenarios for Potato Point
185
Table 9-35 Medium to Long Term Water Cycle Management Opportunities for
Dalmeny, Kianga and Narooma
189
Table 9-36 Social and Environmental Aspects of the Medium to Long Term
Opportunities for Dalmeny, Kianga and Narooma
190
Table 9-37 Integrated Water Cycle Management Scenarios for Dalmeny,
Kianga and Narooma
191
Table 9-38 Triple Bottom Line Assessment of Scenarios for Dalmeny, Kianga
and Narooma
192
Table 9-39 Cost Estimates of Medium to Long Term Water Cycle
Management Opportunities for Mystery Bay
195
Table 9-40 Social and Environmental Aspects of The Medium to Long Term
Opportunities for Mystery Bay
197
Table 9-41 Integrated Scenarios for Mystery Bay
198
Table 9-42 Triple Bottom Line Assessment of Mystery Bay
199
Table 9-43 Integrated Water Cycle Management Options for Central Tilba and
Tilba Tilba
203
xix
Eurobodalla Integrated Water Cycle Management Strategy
xx
Table 9-44 Social and Environmental Aspects of The Medium to Long Term
Opportunities for Central Tilba and Tilba Tilba
204
Table 9-45 Integrated Scenarios for Central Tilba and Tilba Tilba.
205
Table 9-46 Triple Bottom Line Assessment of Central Tilba and Tilba Tilba
206
Table 10-1 Shire Wide Integrated Water Cycle Management Scenarios
211
Table 10-2 TBL Assessment for Shire Wide Scenarios
220
Eurobodalla Integrated Water Cycle Management Strategy
FIGURES
Figure 1-1 The Natural Water Cycle
3
Figure 1-2 The Modified Water Cycle
4
Figure 1-3 The Integrated Water Cycle
5
Figure 6-1 Demographic Profile
38
Figure 6-2 Historical Population Graph
38
Figure 6-3 Past and Future Growth Rates
39
Figure 6-4 Population Served with Water and Sewerage Services
40
Figure 6-5 Historical Dwelling Growth
41
Figure 6-6 Past and Future Holiday Dwellings as a Proportion of the Total
Housing Stock
41
Figure 6-7 Historical Occupancy Levels
42
Figure 6-8 Past and Future Household Size
42
Figure 6-9 Proportion of Water Harvested from Each River
44
Figure 6-10 Urban Communities Water Consumption Profile
45
Figure 6-11 Historic Residential Demands
46
Figure 6-12 Forecast of Regional Schemes Average Annual Water Demand
48
Figure 6-14 and Figure 6-13 shows the regional schemes current and future
average annual and peak day water demand splits between the
northern, central and southern urban areas.
48
Figure 6-14 Split of the Average Annual Regional Demands by Area –
Contemporary Approach
49
Figure 6-15 Peak Day Demand Forecast – Contemporary Approach
49
Figure 6-16 Forecast of Regional Schemes Residential Demands
50
th
Figure 6-17 The Effect of a 95 Percentile 30% Access Licence Condition on
Secure Yield
56
th
Figure 6-18 The Effect of an 80 Percentile 30% Access Licence Condition on
Secure Yield
57
Figure 8-1 Typical Residential Water End Uses for 2002 and 2032 with natural
propagation of water efficient appliances
68
Figure 8-2 Major Water Users by Customer Category (ML)
70
Figure 8-3 Bulk Production, Metered Consumption and UFW Figures From
1995 to 2001
71
Figure 8-4 Potential Water Savings Through a Comprehensive Demand
Management Program
77
Figure 8-5 Topographic Layout of Northern Regional Scheme
95
Figure 8-6 Southern Regional Reuse Scheme
96
Figure 9-1 South Durras Location
106
Figure 9-2 Aerial Photograph of South Durras
107
Figure 9-3 Nelligen Location
117
Figure 9-4 Aerial Photograph of Nelligen
118
Figure 9-5 Batemans Bay Topographic Map
127
Figure 9-6 Batemans Bay Stormwater Sub-Catchments
129
xxi
Eurobodalla Integrated Water Cycle Management Strategy
xxii
Figure 9-7 Mogo Topographic Map
140
Figure 9-8 Rosedale and Guerilla Bay Location
142
Figure 9-9 Aerial Photograph of Rosedale and Guerilla Bay Showing Their
Proximity to Tomakin and Mossy Point
143
Figure 9-10 Tomakin Topographic Map
151
Figure 9-11 Tomakin Stormwater Sub-Catchments
153
Figure 9-12 Moruya Topographic Map
159
Figure 9-13 Location of Congo
165
Figure 9-14 Aerial Photograph of Congo
166
Figure 9-15 Location of Bodalla
171
Figure 9-16 Aerial Photograph of Bodalla
172
Figure 9-17 Potato Point Location
178
Figure 9-18 Aerial Photograph of Potato Point
179
Figure 9-19 Dalmeny, Kianga and Narooma Topographic Map
186
Figure 9-20 Dalmeny/Kianga/Narooma Stormwater Sub-Catchments
187
Figure 9-21 Mystery Bay
193
Figure 9-22 Central Tilba and Tilba Tilba Location
201
Figure 9-23 Akolele Topographic Map
207
Figure 10-1 Traditonal Scenario
212
Figure 10-2 Integrated Scenario 1
213
Figure 10-3 Integrated Scenario 2
214
Figure 10-4 Integrated Scenario 3
215
Figure 10-5 Integrated Scenario 4
216
Figure 10-6 Integrated Scenario 5
217
Figure 10-7 Integrated Scenario 6
218
Figure 10-8 Integrated Scenario 7
219
Figure 12-1 Management Option 1
235
Figure 12-2 Management Option 2
235
Figure 12-3 Management Option 3
236
Eurobodalla Integrated Water Cycle Management Strategy
Glossary of Abbreviations and Terms
Blackwater
Water from the toilet
Dual Reticulation
The provision of reclaimed water through a second set of pipes
for non-potable uses, in addition to potable water through the first
set of pipes
DCP
Development Control plan
DUAP
Department of Urban Affairs and Planning (now Planning NSW)
DLWC
Department of Land and Water Conservation
ESC
Eurobodalla Shire Council
EPA
Environmental Protection Authority
Greywater
Water from a household, excluding toilet water
ha
Hectares
IWCM
Integrated water cycle management
kL
Kilolitres (1 000 litres)
kL/d
Kilolitres per day
kL/a
Kilolitres per annum
L
Litre
L/d
Litre per day
LEP
Local environmental plan
ML
Megalitres (1 000 000 Litres)
ML/d
Megalitres per day
ML/a
Megalitres per annum
NPV
Net present value
Off River Storage
A storage (often located on an intermittent stream) to which water
from a river is diverted during times of high flow for use during
times of low flow
Potable Water
Water suitable for consumption
RWT
Rainwater tank
REP
Regional environmental plan
SEPP
State Environmental Planning Policy
Stormwater Detention
Holding stormwater on-site for a period of time before releasing it
downstream
Stormwater Retention
Keeping stormwater on-site for reuse
STP
Sewage Treatment Plant
WFP
Water filtration plant
WM Act
Water Management Act (2000)
WSUD
Water sensitive urban design
xxiii
Eurobodalla Integrated Water Cycle Management Strategy
95/30
Refers to a condition under which water is licenced for extraction
th
from the river. 95 refers to the 95 percentile of flows, that is the
highest 95% of the time the river flows the water can be
extracted. The remaining 5% of the time is when the river is little
water and this may not be extracted. 30 refers to the the amount
of water in the river that must be shared between the users (30%)
80/30
Refers to a condition under which water is licenced for extraction
th
from the river. 80 refers to the 80 percentile of flows, that is the
highest 80% of the time the river flows the water can be
extracted. The remaining 5% of the time is when the river is little
water and this may not be extracted. 30 refers to the the amount
of water in the river that must be shared between the users
(30%). An 80/30 condition protect the river more than a 95/30
condition
xxiv
Eurobodalla Integrated Water Cycle Management Strategy
1 Introduction
1.1
Overview
Water is a precious natural resource essential for the maintenance of ecosystems and
human activities. NSW is now at the limits of its available water resources and there is clear
evidence of the degradation of our rivers, groundwaters and estuaries. In response, new
water legislation has been introduced in NSW to provide for the sustainable and integrated
management of the State’s water sources for present and future generations.
Integrated Water Cycle Management (IWCM) by local water utilities is a way of managing
the urban water cycle in which all parts of the water system are integrated so that water is
used optimally. This optimal use should result in minimal impact on the water resource and
on other resources and users. For a local water utility this means that the three main urban
services – water supply, sewerage and stormwater – should be planned and managed in an
integrated manner to ensure that the maximum value is obtained from the resource, and
that environmental impacts are minimised. Integration also means that local water
management is integrated with other human waste management and recycling processes
such as garbage removal, and various external elements. These elements may include
issues of global importance such as the greenhouse effect, as well as the natural
processes within the catchment areas, Commonwealth and State policies, neighbouring
water utilities and the community.
1.1.1
The Integrated Water Cycle Management Process
The IWCM process is based on three simple questions, which are:
1.1.2
!
What is the problem? relates to water cycle management impacts (or perceived
impacts) as well as water management problems. To answer this question
necessitates an understanding of the catchment in order to set a benchmark on the
resource needs and availability.
!
How do we fix the problem? looks at addressing water management problems
and requires an understanding of State Government water reform policies, which
describe key water management issues and the appropriate management
responses to them. Since there is more than one management option, a balanced
outcome planning is used to select the best overall option.
!
The last question, How do we know the problem is fixed? is the process by
which we confirm that all impacts are managed to the desired level and water use is
optimised using social, economic and environmental objectives.
Balanced Outcomes Planning
The balance outcomes process aims to give equal weight to each of the three parts of the
triple bottom line (environment, social and economic) when choosing new management
options. The six steps of balanced outcomes planning are:
1
Eurobodalla Integrated Water Cycle Management Strategy
1.1.3
1.
Setting goals
2.
Identifying management options
3.
Coarse screening of options
4.
Economic analysis and ranking of the options
5.
Bundling the options to achieve goals
6.
Examining trade-offs and revising goals
Principles of Integrated Water Cycle Management
Integrated Water Cycle Management is based on the following set of guiding principles:
1.1.4
!
Consideration of all water sources (including effluent and stormwater) in water
resource planning
!
Consideration of all water users (including the environment)
!
Sustainable and equitable use of all water sources
!
Integration of water uses and natural water processes, and
!
A whole of catchment integration of natural resource use and management.
Objectives of Integrated Water Cycle Management Strategy
The objectives of an Integrated Water Cycle Management Strategy are as follows:
2
!
To identify key water cycle issues in Eurobodalla Shire
!
To identify the urban context for these issues, and
!
To offer management options that can control these issues.
Eurobodalla Integrated Water Cycle Management Strategy
1.2
1.2.1
The Water Cycle
The Natural Water Cycle
Figure 1-1 The Natural Water Cycle
The natural water cycle is nature’s system of water circulation. Water falling as rain is
transpired by trees and vegetation, percolates into groundwater or runs into lakes, rivers or
oceans from which it evaporates, to fall again as rain in an endless cycle. This is shown in
Figure 1-1.
3
Eurobodalla Integrated Water Cycle Management Strategy
1.2.2
The Human Water Cycle
Figure 1-2 The Modified Water Cycle
Mankind alters the natural cycle by diverting water for human use, and returning treated
wastewater and stormwater to the environment. This often causes significant impact on the
organisms living in and activities depending on the land and water environment. This is
shown in Figure 1-2.
4
Eurobodalla Integrated Water Cycle Management Strategy
1.2.3
Integrated Water Cycle Management
Figure 1-3 The Integrated Water Cycle
As illustrated in Figure 1-3, the IWCM improves the efficiency of human water use through
the steps of diversion, storage, distribution, use, treatment and recycling so that needs are
met with least cost to users and least impact on the environment. This report outlines the
opportunities and options available for the community of Eurobodalla Shire to achieve these
goals.
The concepts of integrated water cycle management include:
1.3
!
Consideration of all parts of local water systems
!
Optimising water use
!
Waste minimisation to reduce pollution loads and water quality impacts
!
System simplification and recycling to reduce costs and impacts
!
Energy minimisation.
Background to Eurobodalla Shire’s Integrated Water Cycle Management
Strategy
Eurobodalla Shire Council’s (ESC) water supply, sewerage and stormwater infrastructure
requires upgrading to meet population growth and legislative standards. To address the
current and emerging issues within the catchment context, it was decided to holistically
5
Eurobodalla Integrated Water Cycle Management Strategy
review and evaluate how the urban water cycle in Eurobodalla Shire could be improved.
Thus this strategy will be used to demonstrate that the improved management of the ‘urban
footprint’ can help to achieve Council’s strategic business objectives, State resource policy
objectives and community expectations for natural resource management. Importantly, the
strategy is:
1.4
!
Driven by the local community and has whole of government support
!
Holistic and comprehensive
!
Long term in its horizon (30 years), but should be reviewed every five years
!
Flexible to accommodate future uncertainties
!
Economically, environmentally and socially responsible.
Eurobodalla Shire’s Progress So Far
The IWCM strategy process for Eurobodalla began in mid-2001 with the Department of
Land and Water Conservation (DLWC) undertaking a ‘Concept Study’ for Eurobodalla Shire
Local Government Area. This study identified the key water cycle issues for Eurobodalla
(Objective 1) and identified the urban context for these issues (Objective 2). The results of
this study (Eurobodalla’s water issues) were presented to Council at the strategic business
objectives workshop and have been summarised in Part C.
During the preparation of the concept study, DLWC and Eurobodalla Shire Council
engaged the Department of Public Works and Services (DPWS) to help in identifying and
detailing the management options that would have the potential to control the issues
identified.
In November 2001, Council staff developed the strategic business objectives for the future
management of the urban water cycle in Eurobodalla Shire. Following development of the
objectives, the first round of community consultation for the Integrated Water Cycle
Management strategy was undertaken. Separate meetings were held at Narooma, Moruya
and Batemans Bay, to identify the management options that the community would like to
see implemented in the future, along with ratification of the strategic business objectives.
The Council has since ratified the strategic business objectives.
In November 2002, a summary document containing the study findings prepared and
presented to Council to seek Council’s input and approval to seek wider community input
based on the summary document. In November 2002, the second round of community
consultation was undertaken, where the water cycle management options identified in the
first round of consultation, together with other opportunities and options, were presented.
Separate meetings were again held at Narooma, Moruya and Batemans Bay.
In October 2002 a two day inter-agency workshop was held to identify any issues and
concerns the agencies may have with the current management of the water services and
the proposed future water management opportunities and to seek ‘in principle’ support to
IWCM opportunities. To seek community document was posted on Council’s web page
and was made available at Council offices. Community feedback was sought until midFebruary 2003. The community feedback and responses to the feedback are contained in
Appendix B.
1.5
Where To From Here?
Parts D and E of this strategy address how Eurobodalla’s IWCM will be delivered in the
future, along with a timeframe for the various delivery stages.
6
Eurobodalla Integrated Water Cycle Management Strategy
Part A
Where Do We Want To Be?
This Part provides an overview of Council’s strategic
business objectives for the future management of the
urban water cycle, and the community’s wants and
preferences with respect to future water cycle
management opportunities.
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Eurobodalla Integrated Water Cycle Management Strategy
2 Strategic Business Objectives
2.1
Overview
A workshop involving key Council staff was held in November 2001, to clearly define the
business objectives for the future management of the urban water cycle for Eurobodalla. In
order to assist in the development of the strategic business objectives, Council’s
Management Plan and the existing water and sewerage strategic business plans were
consulted together with the State’s South East Catchment Management Blueprint (Ref. 3)
and the EPA’s Water Quality and River Flow Interim Environmental Objectives (1999).
The Strategic Business Objectives define Council’s long term goals for the management of
its landscape and the services it provides, in this instance the water services, and the
outcome on which it would like to be measured.
Since the services it provides are community oriented and have an influence on the
landscape, Council has long recognised the need to measure its water business
outcomes/performance not only in terms of financial bottom line but also taking into account
the broader environmental and social bottom lines. To meet these outcomes and to audit its
performance, Council provides appropriate internal support processes, systems and
structures.
Strategic Business Planning for both the outcomes and internal drivers is developed by
Council staff using their normal business planning. In the case of Eurobodalla, its business
plan for water services was over five years old. Thus at the beginning of this study Council
decided to review its Strategic Business Objectives relating to the outcomes area of
finance, environmental and social. A facilitated workshop was held with Council staff at the
beginning of this study (November 2001). Key representatives from DLWC attended the
workshop to make presentations on current government reforms and the future direction of
the water industry. The workshop was facilitated by DPWS.
The contemporary strategy planning was used for the development of the objectives in the
three outcome areas of finance, environment and social. The contemporary strategy
planning requires the identification of objectives that are measurable, the index to be
measured (KPI) and the associated target. This assists Council to directly assess each
IWCM strategy against the strategic business objective and the associated target.
In developing the objectives, the environmental outcome was looked at from the
perspective of compliance and requirements. The financial outcome looked at both the cost
and revenue sides, and the social outcome looked at product/service quality and
characteristics for the different customer categories in each of the water supply, sewerage
and stormwater service lines.
Identifying the objectives of the internal support processes, systems and structures is
beyond the scope of this study. Based on the outcome of this IWCM strategy, Council
should develop the appropriate objectives, KPI’s and targets for each of these internal
drivers using the guidelines for preparing the strategic business plans for water and
sewerage (Appendix A).
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Eurobodalla Integrated Water Cycle Management Strategy
2.2
The Business Objectives
The following lists represent the objectives developed for the three outcomes reporting
areas. Appendix A contains information on how each objective will be measured, with their
respective target. It also provides information as to which water service the objective
applies. Underpinning these objectives is the need to conserve, efficiently use, reclaim and
recycle urban water to maximise economic and community benefits and minimise
environmental impact.
Environment
!
Ensure efficient use of drinking water
!
Ensure the sustainability of the water resources
!
Reduce greenhouse gas emissions
!
Help protect catchments and estuaries
!
Protect the health and diversity of the receiving waters
!
Ensure the sustainability of reuse areas
!
Minimise the impact of stormwater runoff from existing landuse
!
Maximise beneficial reuse
!
Minimise the impact of the stormwater generation potential of future development
through sustainable development and design
!
Protect the recreational value of the waterways and beaches.
Social
10
!
Maintain continuous access to service
!
Maintain continuous water supply to towns
!
Protect the public safety of the urban community
!
Protect the urban properties and premises
!
Enhance the ‘nature coast’ perception amongst visitors
!
Minimise water supply interruptions
!
Protect public health
!
Provide good quality drinking water
!
Maintain adequate pressure at the household
!
Maintain adequate fire fighting services
!
Increase public awareness of urban water issues
!
Increase customer satisfaction.
Eurobodalla Integrated Water Cycle Management Strategy
Financial
!
Improve efficiency of systems
!
Reduced debt reliance
!
Provide services that are equitable and affordable
!
Minimise the impact on current ratepayers for future infrastructure development
!
Reduce illegal activities such as waste dumping
!
Minimise non-compliance with legislation
!
Improve the performance of the assets
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Eurobodalla Integrated Water Cycle Management Strategy
3 Community Wants, Needs and
Feedback
3.1
Community Wants and Needs Identification
Facilitated community consultation sessions were carried out at Narooma, Moruya and
Batemans Bay in November 2001 to identify community concerns with respect to
Eurobodalla’s water services. The community consultation sessions provided a forum
through which the community was able express their wants and needs for the future
sustainable management of the water services. The community identified a broad range of
opportunities that required consideration in the IWCM strategy. The collated concerns,
wants and options are listed below.
3.1.1
3.1.2
3.1.3
3.1.4
Environmental Values in Relation to Urban Waters
!
Water conservation
!
Environmental protection
!
Sustainable design
!
Environmental flows.
Urban Development
!
Improved development controls
!
On-site stormwater detention for new developments
!
Independence of villages in terms of waste management and sustainable
development
!
Improved planning instruments and environmental impact assessments.
Issues for Future Development of Urban Water Services
!
Secure water supply
!
Reuse
!
Alternative water sources
!
Public health.
Options to be Considered in the IWCM Strategy
!
Rainwater tanks
!
Subsidies/incentives for water saving
!
Stormwater collection
!
Off-river storage dams.
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Eurobodalla Integrated Water Cycle Management Strategy
A more comprehensive list of the above concerns, wants and options is provided in
Appendix B, along with information showing where and how these concern wants and
options s have been addressed in this report.
3.1.5
Community Preferences
Table 3-1 below provides a summary of community preferences with respect to the future
management of their urban water cycle from the November 2001 meeting. The table also
provides the community’s expectations of each water cycle management option in terms of
social and environmental outcomes. Appendix B contains the outcomes of the first round of
community consultation.
Table 3-1 Community Expectations
Issue
Reliable
Water Supply
Healthy
Waterways
Option
Community Expectations
Social
Environmental
Increase our stored water (bigger dam)
1
1
Improve our water quality (treatment
plants)
3
1
Saving water (demand management)
3
3
Recycling water you have already used
(effluent and stormwater reuse)
3
2
Capturing your water needs locally
(rainwater harvesting)
3
3
Using ocean water (desalination)
3
1
Using recycled groundwater (effluent
recharge of aquifer)
3
2
Water sensitive urban design
3
3
Non-structural stormwater
3
2
Improved treatment
3
2
Sewage system integrity
3
3
Planning
3
3
Returned flows
3
2
Environmental flows (leaving water in
the river)
3
2
Education
3
3
Scale: High = 3, Medium = 2, Low = 1
3.2
Community Feedback
The approach adopted by Council top gain community feedback on the options was to have
a series of information sessions and then to publicly display a summary document for
residents to submit comments. The community information sessions were held in Narooma,
th
Batemans Bay and Moruya. The last date receive comments was 15 February 2003.
Appendix B contains the community feedback received and the responses to it.
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Eurobodalla Integrated Water Cycle Management Strategy
4 Integrated Water Cycle
Management Tools
4.1
Overview
IWCM tools is a list of traditional and emerging opportunities that are available to
communities for the management of their water services. These opportunities could be
utilised independently or conjunctively depending upon community preferences and the
triple bottom line benefits they offer for the local area.
The fact sheet for each opportunity provides a brief overview of the opportunity, examples
where it is used and the benefits is offers.
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Eurobodalla Integrated Water Cycle Management Strategy
FACT SHEET 1
Water Sensitive Urban Design
What is Water Sensitive Urban Design (WSUD)?
" WSUD is the consideration of the opportunities and linkages between urban design,
landscape, architecture and water management. It considers all aspects of IWCM as part of
the design process for site and urban development.
" WSUD aims to keep the balance between infiltration and runoff from site and urban areas as
close as possible to the pre-development balance.
" WSUD is an important concept where water use can be optimised through effective planning
undertaken prior to development. This applies to whole-of-development design as well as
design of individual dwellings.
" WSUD tools include:
♦
♦
♦
♦
♦
♦
♦
♦
rainwater tanks
drainage lines along contours
grassed swales to filter out contamination
stormwater detention and exfiltration ponds
non-disturbance of natural drainage lines
water efficient household devices
use of drought-tolerant plant species
on-site greywater reuse
♦
reclaimed water reuse in garden watering and toilets.
" Eurobodalla Shire Council’s Stormwater Management Plan has identified a number of
measures to minimise stormwater impacts. These include source control rather than remedial
end-of-pipe management options, and the encouragement of water-sensitive urban subdivision
design through policies, DCP and building codes. Specific WSUD opportunities for Eurobodalla
are discussed in section 8.1.3.
Examples
" Wyong Shire Council has approved the design of a new subdivision in Warnervale that is
utilising ideas such as rainwater tanks, grassed swales and subsoil infiltration drains, rather
than conventional stormwater pipe drainage practices.
" A subdivision at Figtree Place in Newcastle has been constructed to include many features of
water-sensitive urban design, including underground rainwater tanks and gravel-filled
infiltration trenches. This subdivision has been designed in such a way that stormwater runoff
from the site has virtually been eliminated. It has resulted in considerable savings.
Benefits
" Reduced stormwater runoff from urban lots
" Reduced pollutant loads of receiving waters
" Allows for the potential down-sizing of proposed stormwater infrastructure
" Increased aquifer recharge
" Reduce demand on potable water supply
" Reduce cost of water supply and stormwater infrastructure.
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Eurobodalla Integrated Water Cycle Management Strategy
FACT SHEET 2
Planning Controls
What are Planning Controls?
" Planning controls are legal instruments made under the Environmental Planning and
Assessment Act 1979. They consist of local environmental plans (LEPs), regional
environmental plans (REPs) and state environmental planning policies (SEPPs), which
describe the current planning status and/or future developments of an area. LEPs are made by
Council and dictate the types of developments allowed in each zone of a local government
area.
" Development control plans (DCPs) are detailed guidelines that illustrate the controls that apply
to a particular type of development or in a particular area. A DCP refines or supplements a
REP or LEP.
" Urban water needs are dictated largely by local environmental planning, urban subdivision
designs, and building designs, before the householder exercises choice.
" Council has the opportunity to play an important role in reducing future water consumption.
This may be achieved through the use of planning controls, for example, that mandate the
installation of water efficient appliances and water sensitive gardens, through its role as the
determining authority for the majority of developments in the area.
" Over the last decade many councils have developed planning frameworks to reduce water
consumption and to minimise stormwater runoff. Incorporated into this framework is the water
sensitive urban design concept (fact sheet 1).
Examples
" Eurobodalla Shire Council, through its Residential Design and Development Guidelines DCP
and building codes, encourages the use of energy efficient fixtures and appliances. This
program also indirectly encourages improved water use efficiency. Installing AAA rated shower
roses, for example, saves hot water and therefore energy for heating. However, the present
focus of the DCP is energy abatement and does not explicitly mention water conservation.
Benefits
" Provides a strong conservation message to the community
" Reduces pollutant loads of receiving waters
" Reducing or delaying large infrastructure costs both up and downstream (e.g. size of mains
and STP augmentations)
" Allows Council to exercise discretion on which end uses and areas of the water cycle to
mandate
" Allows Council to set controls before market forces influence customer’s purchasing decisions
of appliances
" Increases environmental benefits through better planning, water and energy use
" Reduced greenhouse gas emission
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Eurobodalla Integrated Water Cycle Management Strategy
FACT SHEET 3
Rainwater Tanks
What are Rainwater Tanks?
" Rainwater tanks store rainwater runoff from roofs. Rainwater is funnelled along gutters into
downpipes, which are connected to the tank. In high rainfall areas, it is possible to harvest
considerable amounts of roofwater using rainwater tanks. Rainwater tanks offer an alternative
water supply for use in the home and/or garden.
" Rainwater tanks may be used as a separate supply source (not supplemented by town water),
or they can be designed to receive a ‘top up’ of town water. A rainwater tank designed for nonpotable indoor uses, for example toilet flushing, typically requires a top up system using trickle
feed technology.
" Rainwater tanks can form an integrated part of the main water supply system, and be subject
to the same restrictions during drought periods as the reticulated supply.
" The recovery of roof water is not only a function of rainfall and tank size, but also a function of
water use. Tanks are more likely to be full during or following wet weather when garden water
needs are low. Connecting tanks to supply water for the toilet and washing machines increases
the utilisation of the rainwater tank and therefore increases
the amount of water tanks can collect every year.
Benefits
" Rainwater tanks collect water from the local area, and if
used correctly, are an effective way to take the demand
and pressure off our limited water resources, our rivers
and storage facilities.
" Rainwater tanks are able to capture roofwater following
small rainfall events during drought periods.
" By storing rainwater runoff from your roof, rainwater tanks can provide a valuable water source
for flushing toilets, in washing machines, watering gardens and washing cars.
" Using rainwater for gardens, washing machines or toilets will save money on water bills.
" Rainwater tanks improve environmental quality through conserving our valuable drinking water
and reducing the demand on our water supply (conserving water also reduces the chemical
and energy requirements for treating and transporting water to your home via the mains
supply).
" Rainwater tanks can help manage stormwater runoff through reducing the amount of
stormwater leaving your property, thereby reducing flooding.
" Rainwater tanks promote awareness of water conservation issues through practice.
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Eurobodalla Integrated Water Cycle Management Strategy
FACT SHEET 4
Effluent Reuse
What is Effluent Reuse?
" Effluent reuse involves the utilisation of suitably treated wastewater for beneficial uses. It
represents a significant move away from the traditional notion of effluent being considered only
as a waste product, which is conventionally disposed of through ocean or waterway discharge.
" Water from sewage treatment plants can be treated to a standard suitable for a range of
applications including industrial reuse, agricultural reuse, non potable domestic reuse, urban
open space reuse and indirect potable reuse (the level to which water must be treated for
different end uses is described in Appendix D).
" Site-specific analysis is required to assess the balances of water, nutrients, organics and
soluble salts to identify the most cost-effective and sustainable options for on-land disposal of
wastewater. Ongoing monitoring is important to ensure sustainability.
Examples
" The REMS (reclaimed effluent management scheme)
project in the Shoalhaven is an extensive irrigation scheme
utilising wastewater from the region. The irrigation scheme
comprises 14 dairy farms, a golf course and sporting fields.
Water is delivered at a constant rate into balancing ponds
on user’s land (see picture right) (www.shoalhaven.nsw.gov.au).
Benefits
" Reclaimed water, used in place of fresh water, reduces the pressure on treated water for nonpotable uses (e.g. open area irrigation) and provides a drought proof irrigation water supply.
" Effluent reuse assists in the preservation of fresh water supplies as well as reduces the need
to use commercial fertilisers on crops and pastures. Treated effluent contains water, plant
nutrients and organic matter, which together can improve soil fertility and encourage plant
growth.
" Effluent reuse can provide regeneration of deteriorated habitats (wetlands).
" Reduces the impact of wastewater discharges on waterways, and enhances resource recycling
with water returned at an earlier stage of the water cycle for recycling.
" Promotes awareness of water conservation issues through practice.
" Assists in meeting legislative and regulatory compliance, and license conditions (e.g. loadbased licensing).
" The use of reclaimed water can have economic benefits, depending on connection fees and
charge per volume, and can reduce the costs of fertilisers. (Suitable studies are necessary to
prevent costly soil structure problems caused by too many nutrients).
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Eurobodalla Integrated Water Cycle Management Strategy
FACT SHEET 5
Effluent Return Flows
What are Effluent Return Flows?
" Effluent return flow is the process of returning highly treated wastewater to waterways. Under
the Water Management Act 2000, credits can be gained from return flows, allowing towns to
access greater extraction volumes. However government agencies have not yet agreed on
water quality requirements and flow regimes for return flows.
" If there are users downstream of the discharge point, the return flow can be credited against
the town’s extraction limit and the town may extract more water.
Benefits
" Increased volume and improved variability of environmental flow releases (thus reducing the
impact on ecological processes).
" Reduces stress on natural habitats.
" Increases yield (security) of the supply in drought or dry periods.
" Enhanced resource recycling, with water returned at an earlier stage of the water cycle for
recycling.
" May downsize or delay the need for other water supply augmentation options (e.g. a dam).
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Eurobodalla Integrated Water Cycle Management Strategy
FACT SHEET 6
Greywater Reuse
What is Greywater Reuse?
" Greywater refers to all wastewater from households excluding toilet water (blackwater). It
includes water from the laundry, sinks and dishwashers, and contains less nutrients and
pathogens than blackwater. It can be collected and treated separately using on-site systems.
" Greywater is typically reused for irrigation purposes.
" The greywater can be treated and disinfected, which can reduce nutrient and bacteria and then
be disposed of through either sub-soil or spray irrigation.
" If the greywater is not disinfected, it should be disposed through subsoil irrigation. NSW Health
advises that if the whole greywater stream, (including kitchen wastewater) is being used for
irrigation, it go through a vessel such as a baffled septic tank because it acts as an efficient
grease trap and anaerobic digester before application.
" If kitchen waste is excluded, NSW Health advises the greywater stream should go through a
stilling and cooling chamber of about 1 cubic metre before sub-soil disposal.
" On-site greywater treatment has the potential to reduce water consumption from other
sources.
" A house with greywater treatment needs to be plumbed to separate the greywater from the
blackwater. Treatment is still required for the blackwater, which may range from a composting
toilet to connection to a reticulated sewerage system.
" Greywater reuse in sewered areas requires consideration of the NSW Health policy Greywater
Reuse in Sewered Single Domestic Premises (2000).
Examples
" Recent UK studies have shown that greywater could be treated to residential reuse grades
using aerated biological filters and membrane bioreactors but the corresponding breakeven
unit water costs were in the order of A$5.00/kL. The development of cost effective residential
greywater reuse technologies is still in the experimental stage.
Benefits
" The use of greywater systems on areas connected to the reticulated supply can reduce the
hydraulic loads on the sewerage system and sewage treatment plant.
"
"
"
"
"
Water is recycled on-site.
Reduces water bill.
On a small scale (residential) maximises potable water used for potable uses.
Maintains an awareness of water conservation issues through practice.
Potential downstream benefits including reducing or delaying large infrastructure and operating
costs (size of mains and STP augmentations, pump out costs).
Potential Hazards
" Household greywater is biologically active and can contain significant levels of bacteria and
other pathogens, which may increase if the greywater is stored for lengthy periods without
treatment. For this reason, health authorities prefer sub-surface irrigation methods.
" Another hazard with untreated greywater systems is the potential for clogging of subsurface
systems by the soaps and oils contained in the greywater.
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Eurobodalla Integrated Water Cycle Management Strategy
FACT SHEET 7
Stormwater Management and Reuse
What is Stormwater Reuse?
" Stormwater reuse involves capturing, storing and treating stormwater to a suitable level for a
variety of beneficial reuses. The most common use is for open space or agricultural irrigation.
" Impermeable surfaces associated with urban development increase the volume of runoff in
urban areas, and consequently the volume of pollutants entering the environment.
Conventional stormwater management has traditionally focused on diverting urban runoff out
of built areas as rapidly and efficiently as possible through drainage systems incorporating
underground pipes and overland flow paths.
" There are a variety of tools to improve stormwater quality, including litter traps, pit inserts,
grass swales, bio-retention trenches and sand filters for control at source points, and gross
pollutants traps, sediment traps and constructed wetlands for end-of-pipe uses.
" Until recently, little recognition has been given to utilising this resource or to protecting the
quality of the water leaving urban areas. Stormwater harvesting can be incorporated into local
stormwater detention and water quality control features.
" Eurobodalla Council’s Stormwater Management Plan has identified a number of measures to
minimise stormwater impacts. These include source control rather than remedial end-of-pipe
management options. Stormwater management opportunities are discussed in Appendix W
and section 8.2.2.
" Based on water quality and construction requirements it is generally more cost effective to
utilise harvested stormwater in water quality control ponds for public landscape needs rather
than to supply residential consumers.
Examples
" The Sydney Olympic Park project harvests stormwater from the water quality control ponds. In
a natural setting following a rainfall event, any water that has not infiltrated the subsurface will
run off the site and be transported to a nearby waterway. This runoff can be intercepted,
collected and stored in a detention basin for later non-potable household use or municipal
landscape irrigation. The yield from a stormwater harvesting systems during dry periods is
dependent on the amount of storage provided.
Benefits
" The temporary storage and reuse of flood waters will have the effect of attenuating the peak
flow rate of discharge downstream, which should reduce the size of drainage works required
downstream.
" Reduces stormwater and flooding impacts.
" Recycling occurs on or near site.
" Reduction in treated water demand and fresh water supplies for non-potable uses such as
irrigation.
" Slows or halts the export of pollutants and contaminants from the catchment to other sensitive
environments.
" Potential to provide new / enhanced natural habitats (for native flora and fauna) or aesthetic
features in urban environments (artificial water bodies).
" If open space is available it can be a cost effective means of upgrading stormwater capacities,
" Reduces erosion associated with runoff.
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Eurobodalla Integrated Water Cycle Management Strategy
FACT SHEET 8
Demand Management
What is Demand Management?
" Water demand management incorporates conservation measures that improve water use
efficiency, increase water reuse and recycling, and minimise water waste.
" It includes measures such as pricing, water efficient devices and water conservation programs.
" Water saved through more efficient water use is as effective as making water
available through constructing new supply infrastructure capacity, with many
additional environmental benefits.
" Demand management incorporates many tools ranging from efficient fixtures
such as AAA rated shower roses and appliances to non-structural solutions
such as education campaigns and demonstrations.
Examples
" As part of Sydney Water’s demand management program, a pilot scheme was implemented in
Shellharbour with approximately 25% of households participating in the program, a figure that
greatly exceeded the anticipated uptake level of 10%. An assessment of the water demand
reductions achieved by the program to date indicate that about 20-25 kL/household/a has been
saved.
" Lismore City Council, as one of the four constituent councils of Rous Water, the bulk water
supply authority for the north coast of NSW, commenced a demand management strategy in
1996, which included a residential retrofit program The trial consisted of retrofitting low flow
shower roses and dual flush toilets to a total of 470 customers. The resulting water savings
were in the order of 24 kL/household/a for the showerheads and 35 kL/household/a for the
toilets. The total cost of the trial, including administrative costs and rebates, was about
$28 000. The trial yielded water savings at a cost of 12 c/kL for the shower roses and 30 c/kL
for the toilet retrofits.
Benefits
" Increases community awareness of importance of water conservation.
" Reduces water consumption.
" Saves Council and the individual household money.
" Decreases greenhouse gas emissions through reduced hot water
consumption and reduced pumping.
" Decreases pressure on natural environments through decreased
water demands.
" On a small scale (residential) maximises potable water used for
potable uses
" Potential up and downstream benefits include reducing or delaying large infrastructure costs
(size of mains and STP augmentations) and operating costs, for example potential to decrease
treatment costs (and chemical use).
" Reduces the frequency and severity of water restrictions.
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Eurobodalla Integrated Water Cycle Management Strategy
FACT SHEET 9
Loss Reduction
What is Loss Reduction?
" Unaccounted-for water (or non-revenue water) is that portion of bulk water production that the
water utility cannot bill as it does not reach the customers’ meter.
" Unaccounted-for water comprises leakage from the distribution system due to breakages and
overflows from reservoirs, illegal connections, fire fighting, mains flushing, overhead fillers and
errors in system flow meters.
" Loss reduction involves reducing the proportion of water lost through the distribution system
due to breakages and overflows.
" The first stage in a loss reduction program involves accounting for where water is lost in the
system and determining the amount that is lost.
" Over time, a well-designed leakage reduction program will identify leakage trouble spots and
allow for programmed maintenance of these areas. As part of the program, system-wide water
consumption is monitored allowing more rapid identification of leaks and illegal connections.
Areas of the distribution system with high pressure can be targeted through a pressure
reduction program, which will also contribute to reduced leakage.
Examples
" Specific loss reduction opportunities can be found in section 8.1.7.
Benefits
" Better understanding of system-wide water consumption.
" Decreased extraction rates for the same volume of water supplied.
" Decreased long term operating costs.
" Greater income for the same volume of water supplied.
" Identification of trouble spots and quicker response time.
" Increased confidence in metering equipment and the data collected.
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Eurobodalla Integrated Water Cycle Management Strategy
FACT SHEET 10
Dams and Storages
What are Dams and Storages?
" Off-river storage (often located on an intermittent stream) involves diverting water from a river
to a storage facility.
"
A dam involves building a structure across the river to regulate the flow of water.
" The need for dams and off-river storage cannot be considered in isolation, but rather requires
consideration in the context of all water supply options due to the significant environmental,
social and financial impacts.
" In terms of environmental and financial costs, off-river storage represents a more sustainable
option than damming rivers. Off-river storages allow water to be pumped out of the river and
stored during high flow periods. During low flow periods (drought) the water in the river can be
left untouched and the water in the storage used to supply consumption needs.
" Off-river opportunities are discussed in section 8.3.4 and appendix K.
" The advantage of keeping water in a dam or storage is that it allows water to undergo some
natural disinfection processes, which can form part of a multi-barrier approach to protect public
health. However, storing water in dams increases the risk of a blue green algae outbreak in the
water supply.
Examples
" Deep Creek Dam is an off-river storage that stores water from the Deua and the Buckenboura
rivers during high flow periods. It supplies water to the Shire during times of low river flows.
Benefits
" Increases the security of supply.
" Can be designed to maintain environmental objectives with flexibility in mind.
" Reduces the pressure on more sensitive environments (sacrifice and save).
" Reduces the severity of restrictions.
" Increases environmental flows during drought.
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Eurobodalla Integrated Water Cycle Management Strategy
FACT SHEET 11
Decentralised Sewage Management
What is Decentralised Sewage Management?
" Decentralised sewage management is an alternative option to connecting all properties to a
centralised sewage treatment system. It can treat sewage from a single household or a small
community.
" Decentralised sewage management includes septic systems and aerated treatment with
effluent disposal options including pump-outs, adsorption trenches, lined evapotranspiration
beds and spray irrigation.
" In Eurobodalla there are currently 3 400 on-site sewage treatment systems registered with
Council. The cumulative effects of multiple poorly performing and aging systems can be
significant. The Wallis Lakes oyster incident provides a good example of the potential risks and
flow on effects from poorly treated sewage.
" Decentralised sewage management systems should meet the following environmental and
health performance objectives over the long term:
♦
Minimised risk to public health
♦
Protection of land
♦
Protection of groundwater
♦
Conservation and reuse of resources
♦
Protection of community amenity
♦
Protection of surface waters.
♦
Specific decentralised sewage management opportunities can be found in section 9.
Examples
" The towns of Nelligen, South Durras, Bodalla, Mystery Bay, Akolele, Potato Point, Tilba Tilba,
Central Tilba, Rosedale, Guerilla Bay and Congo use decentralised sewage systems.
Benefits
" Can adapt the system to reflect local characteristics
" Sewage is treated on site.
" Effluent treated to a high quality can be used locally.
" Improved compatibility with other IWCM options.
" Downstream benefits including reducing or delaying large infrastructure costs (size of mains
and STP augmentations).
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Eurobodalla Integrated Water Cycle Management Strategy
5 Integrated Water Cycle
Management Options
Assessment Criteria
5.1
Overview
Having briefly outlined ‘where we want to be’ from the Council, community and government
perspective, criteria for assessing the various IWCM opportunities and options could then
be developed.
5.2
The Assessment Criteria
Table 5-1 below presents the assessment criteria that were used for ranking each IWCM
option developed in this report.
27
Eurobodalla Integrated Water Cycle Management Strategy
Table 5-1 IWCM Assessment Criteria
Environmental
Efficient use of fresh water
resource
Options that result in savings in town water resources (low flow toilets and
showers, water pricing, rainwater tanks).
Minimises low flow water
extractions
Beneficial use of alternative water resources providing ecosystem protection,
increase extraction during high flows.
Minimises greenhouse gas
emissions
Postponement or cancellation of construction, minimises energy
consumption, and promotes the use of green energy.
Minimises pollutants being
discharged to the aquatic
environment
Improves water, sewage and stormwater systems, which reduce the level of
nutrients, chemicals, suspended solids and pathogens entering the
environment.
Minimises urban stormwater
volumes
Options that result in reduced volume and velocity of stormwater discharge,
e.g. retention/detention basins.
Ensure sustainable land use
practices
Options that ensure land management practices are sustainable including
those that result in increases in riparian vegetation, reduction in soil erosion,
management of acid sulfate soils, etc.
Social
Improves security of town
water supply
Options that reduce the potential for water restrictions and/or meet growth
requirements.
Improves the quality of
drinking water
Options that increase the quality of the potable water supply including land
management and treatment technologies.
Improves urban water service
levels
Ensures adequate pressure needs for domestic and fire fighting requirements,
reduces service interruptions, sewage blockages, customer complaints.
Increase public awareness of
urban water issues
Options that improve the public awareness of the urban water cycle, e.g.
public education in programs for water efficiencies, litter reduction and waste
dumping.
Minimises non-compliance to
policy and legislation
Option that recognises all policy and legislative issues.
Protects public health
Options that improve drinking water quality, recreational water quality and
aquatic seafood water quality.
Enhances the ‘nature coast’
perception
Options that support the image of the area with regard to being ecologically
sustainable and pristine.
Financial
28
Minimises the impact of future
infrastructure development on
current ratepayers
Options that consider inter- and intra-generational equity.
Improves the performance of
the assets
Options that make existing assets last longer and/or operate more efficiently.
Provides services that are
equitable and affordable
Options that consider equity and affordability issues, particularly in relation to
small communities.
Improves efficiency ratios
Options that improve the operational efficiency of assets and service delivery.
Reduces debt reliance
Options that help to reduce the amount of money Council (and ratepayers)
have to borrow and pay back.
Eurobodalla Integrated Water Cycle Management Strategy
Part B
What Are the Issues?
This part provides an overview of the issues relating to
reform and legislative compliance, catchment
management, urban planning, water infrastructure
performance and community expectation.
29
Eurobodalla Integrated Water Cycle Management Strategy
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30
Eurobodalla Integrated Water Cycle Management Strategy
6 What are Eurobodalla’s Issues?
6.1
Government Initiated Reform Compliance Issues
In the early 1990s, the Council of Australian Governments (COAG), consisting of the Prime
Minister, State Premiers, Territory Chief Ministers and the President of the Australian Local
Government Association agreed to implement the national competition policy across
Australia. The policy framework was based on macro- and micro- economic reforms across
the various levels of governments to achieve efficiency, equity and transparency in
governance and to achieve sustainability in resource management. The implementation of
the national competition policy is Commonwealth funded, with payments based upon the
completion of certain levels of the policy. The NSW Government has therefore embarked
upon a number of independent but related reforms within the framework of the competition
policy. Some of these reforms, relevant to this study, include the water reforms, full cost
recovery service pricing of essential monopoly community services, transparencies in
decision making and regional capacity building. The subsequent sections provide a brief
overview of these reforms and Eurobodalla’s compliance status with these reform
objectives.
6.1.1
Water Reforms and the Water Management Act 2000
The water reforms are a key driver of change for all water users. In 1994, COAG agreed to
implement the strategic framework to achieve an efficient and sustainable water industry.
The water reform aims to achieve clean healthy rivers and sustainable water use in
consultation with the community and stakeholders. As part of these reforms the NSW
government introduced the Water Management Act 2000 (WM Act).
The WM Act introduced in 2000 aims to achieve a better balance between water use and
environmental protection by setting environmental objectives for all NSW rivers covering
river flow and water quality objectives. The Act acknowledges the environment as a
legitimate water user and therefore aims to ensure that it is guaranteed a certain allocation
of water. The aim of the Act is to clearly identify all water users, and formalise their share
and access rights.
Under the WM Act, draft management plans are to be developed for each land
management area in the State. In the Eurobodalla Shire, the three main catchments, Clyde,
Tuross and Moruya, require management plans to be developed. Water-sharing plans are
one of the many plans included as part of the management plans. These plans will
establish the environmental water rules, the requirements for basic landholder rights, the
requirements for water extraction under access licenses, and the bulk access regime (BAR)
for extraction licenses.
The BAR refers to water available for extraction after provisions have been made for
environmental water and basic landholder rights. Various classes of environmental water
have been identified for the purpose of setting the BAR. The rules for the identification,
establishment and maintenance of each class of environmental water (environmental water
rules) are to be established for all of the water sources in the State, by means of a
management plan.
Once the provisions to satisfy basic landholder rights and the environmental water rules
have been established, water will then be allocated under access licenses. Access licenses
fall into a number of categories and are subject to a system of priority.
31
Eurobodalla Integrated Water Cycle Management Strategy
!
Local water utility access licenses, major utility access licenses and domestic and
stock access licenses have priority over all other access licenses.
!
Regulated river (high security) access licenses have priority over regulated river
(general security) access licenses and regulated river (supplementary water)
access licenses.
!
Finally regulated river (general security) access licenses have priority over
regulated river (supplementary water) access licenses.
All water rights are reduced in periods of low flow, although those with a higher priority
licence will have their allocation diminished at a lesser rate.
The amount of water required to be left for the environment has yet to be determined by the
water management committees. It is likely though that the first water-sharing plan will
th
require that the lowest 5% of the flows be left for the environment (95 percentile). When
the plans are reviewed after the mandated 10-year period, it is possible that in light of
additional environmental data the environment may be allocated the lowest 20% of the
th
flows (80 percentile). Of the water left in the river it is likely that only 30% will be available
for extraction by all users.
It is generally accepted that ecosystems are highly vulnerable during low flow periods, but
that natural flow regime variations are important to ensure a healthy and diverse ecological
community. Developing draft management plans can be difficult in the absence of river flow
management plans and specific local scientific knowledge about the ecology and
conservation values of these river systems. It has been suggested that the precautionary
principle be adopted in the future planning of the regional water supply scheme and in the
development of draft management plans. The precautionary principle states that if there are
threats of serious or irreversible environmental damage, a lack of full scientific certainty
should not be used as a reason for postponing measures to prevent environmental
degradation.
Under the WM Act, town water use is subject to a maximum extraction volume. This
maximum volume can be calculated in one of three ways:
Existing entitlement: Many towns already have a volume entitlement specified in their
works license or in a legal agreement.
Reasonable entitlement: The volume of water the town can extract is calculated by
reference to the demographic and geographic characteristic of the town, assuming
reasonable demand management measures are in place.
System capacity: A volume of water calculated on the basis of the current yield of the
water management works.
Where the volume calculated for the access license is greater than the volume currently
used, the town may need to seek the Minister’s consent before extracting this extra water.
Town water access licenses are to be reviewed every five years and varied according to the
changes in population. However no allowances for additional water for new or expanded
industries are made in this review. For Eurobodalla this means that additional water needs
for commercial, agricultural or industrial uses within a town water supply will need to be met
by:
32
!
Surplus water within the town’s defined license volume
!
Water efficiency gains
!
The industry obtaining their own access through the purchasing of water from other
users.
Eurobodalla Integrated Water Cycle Management Strategy
Thus when considering the supply of non-urban users, Council must consider how it will
source the water before committing to supply them. Other water sources may be
appropriate for such users (e.g. reclaimed effluent).
Protection of River Flows and Aquifers
The water reforms aim to improve the health of rivers and groundwaters to ensure long
term, secure and viable regional economies. The quality and quantity of water available in
the rivers and streams is seen as an indicator of degradation.
As part of the NSW Government’s reforms to ensure the long term sustainability of the
rivers, Water Quality and River Flow Interim Environmental Objectives have been
developed by the EPA (1999). These objectives are designed to guide plans and actions to
achieve healthy waterways. The water management committees, in developing the water
management plans, are required to utilise these objectives.
The water quality objectives aim to protect:
!
Aquatic ecosystems
!
Visual amenity
!
Primary contact recreation
!
Secondary contact recreation
!
Livestock water supply
!
Irrigation water supply
!
Homestead water supply
!
Drinking water
!
Aquatic foods.
The river flow objectives aim to:
!
Protect pools in dry times
!
Protect low natural flows
!
Protect important rises in water levels
!
Maintain wetland and floodplain inundation
!
Mimic natural drying in temporary waterways
!
Maintain natural flow variability
!
Manage groundwater for ecosystems
!
Minimise effects of weirs and other structures.
The IWCM strategy for Eurobodalla is an important step in achieving the overall reform
objectives. In particular this strategy addresses:
6.1.2
!
Community and stakeholder consultation in the formulation of strategies
!
Innovation in the development of urban water services infrastructure
!
Water conservation and water quality management, and its importance in the
catchment context
Pricing Reforms
A brief review of ESC’s current pricing policy for water services indicates the following noncompliance:
33
Eurobodalla Integrated Water Cycle Management Strategy
6.1.3
!
The process used for establishing fixed water and sewerage service access
charges is not transparent.
!
The NSW Government recently released guidelines for best practice standard for
water and discharge prices. ESC water use charges are close to best practice.
Sewer discharge pricing for non-residential developments requires addressing to
create equitable charges and recoup true costs of operations.
!
Although the Council has established the ‘true’ cost of providing water, sewerage
and stormwater services to new developments, the current level of developer
contribution is far less than this ‘true’ cost. This results in significant subsidy to
developers by the existing ratepayers and also results in revenue loss to Council.
!
There is inadequate funding for urban stormwater management and treatment
measures and for catchment improvement works. This is in part due to the fact that
the cost of providing these services is funded through the general rates, which are
currently ‘pegged’ by the State Government.
Legislative Compliance issues
The NSW Government, through the use of a number of legal instruments, regulates the
provision of water services by ESC. The key administering agencies responsible for these
legal instruments, along with other relevant responsibilities, are listed below.
Eurobodalla Shire Council
!
Preparation of LEPs and DCPs
!
Development approvals under Part 4 of the Environmental Planning and
Assessment Act 1979, which are required to be consistent with relevant SEPPs and
REPs
!
Development and ongoing operation of the water, sewerage and stormwater
systems schemes
!
Owners of the physical water infrastructure assets
!
Local area and infrastructure management and planning approvals under the Local
Government Act 1993
!
Funds maintenance and upgrading of physical water infrastructure assets
!
Lower South Coast REP No. 2 – Provides a framework for local planning and
development in the Bega Valley and Eurobodalla Shire.
Department of Land and Water Conservation
34
!
Administration of the Water Management Act 2000 and the Native Vegetation
Conservation Act 1997
!
Licensing provisions under the Rivers and Foreshores Improvement Act 1948, and
the Water Act 1912 (these provisions are still in force until repealed in mid-2003)
!
Financial subsidy under the Country Towns Water Supply and Sewerage Schemes
program
!
Local Government Act 1993 section 60 approvals for water supply and sewerage
schemes and infrastructure including trade waste discharge to sewer
Eurobodalla Integrated Water Cycle Management Strategy
!
Natural resource (river flow, groundwater and land) management
!
Water and sewage treatment plant approval for rural water utilities
Environment Protection Authority
!
Pollution regulators
!
Development concurrence approval for pollution mitigation facilities under the
Protection of the Environment Operations Act 1997
!
Licensing of sewerage systems, including STPs and effluent reuse schemes, under
the Protection of the Environment Operations Act 1997
!
Licensing discharge from water treatment plants under the Protection of the
Environment Operations Act 1997
!
Pollution reduction programs and load based licensing
!
Water Quality and River Flow Interim Environmental Objectives
!
Draft Effluent Reuse Guidelines
!
Funding of stormwater quality objectives
Planning NSW
!
Planning approvals under the Environmental Planning and Assessment Act 1979
and various SEPPs, for example SEPP 4, SEPP 26, SEPP 14, SEPP 33, SEPP 71
Department of Health
!
Protection of public health under Public Health Act 1991
Department of Local Government
!
Policy and legislative framework for local government
Southeast Catchment Management Board and South Coast Water Management
Committee
!
River flow and quality objectives
!
Development of the water-sharing plans
!
Development of Catchment
Management Plans)
Management
Blueprints
(formerly
Catchment
Other agencies and their responsibilities are discussed below.
35
Eurobodalla Integrated Water Cycle Management Strategy
Healthy Rivers
Commission
-
Long term sustainability of water catchments and
resources including effluent management
-
Workplace and employee safety
-
Dangerous Goods Act 1975 for the storage of chemicals
required for STPs and WTPs.
-
Protection of fishing industries, aquatic habitat and
threatened species under Fisheries Management Act
1994
-
Approvals for dredging works to be carried out.
-
National Parks and Wildlife Act 1974
-
Threatened Species Conservation Act 1995
-
Manages National Parks and the protection of threatened
species in Eurobodalla’s catchments.
-
Provides advice on protection and management of
agricultural resources
-
Provides advice on reclaimed water irrigation schemes.
Sydney Catchment
Authority
-
SEPP 58 Protecting Sydney’s Water Supply.
Forestry
-
Manages land in Eurobodalla’s water catchments
Work Cover Authority
NSW Fisheries
NSW National Parks and
Wildlife Service
NSW Agriculture
6.2
Catchment Issues
An area bounded by natural features such as hills or mountains, where all runoff water
flows to a low point, is a water catchment. Eurobodalla has three major catchments, Clyde,
Tuross and Moruya. Water extracted from the Buckenboura, a tributary of the Clyde, the
Deua, which flows into the Moruya, and water taken directly from the Tuross, make up the
Eurobodalla town water supply. In additional there are numerous small coastal catchments
that contain intermittently open coastal lakes and small coastal inlets. These lake systems
are of environmental significance and are sensitive to impacts from neighbouring
developments. The Southeast Catchment Management Board oversees the management
of these catchments.
It is important that catchments are managed in a sustainable fashion and that the land uses
within a catchment are consistent with the physical features of the land. Catchment
objectives provide direction for the management of the catchment.
6.2.1
Environmental Issues
The following points are a summary of the main environmental issues in Eurobodalla.
36
!
Erosion in the upper Deua catchment due to deforestation, causing high levels of
sediment washout into downstream river reaches and estuary
!
Agricultural water use during low flows is impacting on river health
!
Areas of dryland salinity
!
Algal blooms reported in Moruya Estuary
!
Uncontrolled microbiological, nutrient and sediment runoff from farms and irrigation
areas
Eurobodalla Integrated Water Cycle Management Strategy
6.2.2
!
Uncontrolled access to water courses for farm animals
!
Septic tank discharges in wet weather
!
Water quality issues within the closed lagoons. These can be due to natural
decomposition of seaweed or urban nutrient impacts from runoff.
Water Quality Issues
Water quality provides an important indicator of overall catchment health. One of the main
environmental objectives of catchment management is to monitor and manage the activities
that impact upon the catchment. The Clyde, Tuross and Moruya Rivers have failed to meet
five of the EPA’s Water Quality and River Flow Interim Environment Objectives (Integrated
water catchment quality plan) criteria. These failed criteria are listed below.
6.3
6.3.1
!
Faecal coliforms
!
pH
!
Turbidity
!
Nutrients
!
Dissolved oxygen (DO).
Urban Planning Issues
Population Distribution
The Eurobodalla Shire covers a large area and varied landscapes, and is bordered by the
Tasman Sea in the east, the coastal mountains to the west, Wallaga Lake in the south and
Lake Durras to the north. More than 85% of the Shire population live along the coast, with
50% of the coastal population located in the Batemans Bay/Tomakin area. Narooma and
Moruya are the other two main business centres, which account for about 20% of the
coastal population. The remaining coastal population (15%) is scattered among the
numerous small villages along the coast.
The remaining 15% of the shire population who live away from the coast are predominantly
located along the major river flats, as their livelihood is based on agriculture. The main
agricultural produce from the Eurobodalla Shire consists of dairying, cattle beef and fodder.
Other significant industries include tourism, oyster farming and forestry.
Demographic Profile
Analysis of the recent census population data shows that around 30% of the population in
the Eurobodalla Shire are aged 60 or older (see Figure 6-1 below). The 20 to 25 and 26 to
29 age group represents the lowest proportion of the population under the age of 80. The
emigration of young adults from the shire and immigration of retirees to the Shire is a
familiar trend across NSW coastal communities.
37
Eurobodalla Integrated Water Cycle Management Strategy
2 ,5 0 0
Number of Persons
2 ,0 0 0
1 ,5 0 0
1 ,0 0 0
500
Overseas visitors
95-99
A g e G ro u p
100 years and over
90-94
85-89
80-84
75-79
70-74
65-69
60-64
55-59
50-54
45-49
40-44
35-39
30-34
25-29
20-24
15-19
10-14
5-9
0-4
0
Figure 6-1 Demographic Profile
6.3.2
Shire-wide Population Growth
The available census records show that the shire has been experiencing a steady
population growth and that the population has doubled since 1980. Characteristic of most
coastal centres in NSW, the 1980s was a period of high population growth stemming
predominantly from the migration of retirees into the shire. The last decade was
characterised by slow but positive growth. The 2001 census shows that the population
growth continues to rise but not as rapidly as experienced in the 1980s (see Figure 6-2
below).
35,000
30,000
Population
25,000
20,000
15,000
10,000
5,000
0
1981
1983
1985
1987
1989
1991
Year
Figure 6-2 Historical Population Graph
38
1993
1995
1997
1999
2001
Eurobodalla Integrated Water Cycle Management Strategy
To develop a cohesive IWCM strategy for the next three decades it is necessary to consider
how rapidly, and in which localities, the population is expected to grow. As part of this study,
previous population projections have been reviewed in consultation with Council’s town
planners. A study undertaken by Macoun (1998) noted that the population was not growing
as fast as that predicted using the 1996 Department of Urban Planning and Affairs (DUAP,
now Planning NSW) projections. These projections were based on the 1991 census. The
study by Macoun kept the gradient of the DUAP low growth curve and corrected for the
lower population.
Since this study, population projections have become available from the Australian Bureau
of Statistics based on the 1996 and 2001 census figures. Thus, in this IWCM strategy the
population projections have been adjusted for the actual growth rate recorded in the shire
and are shown in Table 6-1. Further detail on growth rates can be found in appendix E.
Table 6-1 Population Projection
Year
Shire Population
2001
33 140
2004
34 694
2009
37 085
2014
39 422
2019
41 697
2024
43 932
2029
46 173
2032
47 514
Table 6-1 shows that the shire population is predicted to increase by about 50% over the
next 30 years. Growth is expected to be concentrated in the north of the shire, and this
region is predicted to account for about 50% of the total growth. An independent study
commissioned by Council (Census Applications Australia, 2002) confirms these projections.
6%
Population Growth Rate
5%
4%
Historical
3%
Adjustment and Extrapolation
of ABS Forecast
2%
1%
ABS Forecast
0%
1980
1990
2000
2010
2020
2030
2040
Five Years Ending
Figure 6-3 Past and Future Growth Rates
39
Eurobodalla Integrated Water Cycle Management Strategy
Although the rural population (that population living away from the coast) is only a small
proportion of the total shire population, the recent deregulation of the dairy industry coupled
with low demand for beef cattle has resulted in the subdivision of many farms. Council is
proactively managing the subdivision of these farming properties to ensure the water cycle
is managed sustainably within each property. Developing future growth and IWCM
strategies for rural subdivisions is beyond the scope of this project.
6.3.3
Population Served With Council Water Services
Figure 6-4 shows the population currently serviced by Council’s water supply and sewerage
system. This figure also represents the expected future demand of these services over the
next 30 years.
50,000
45,000
40,000
Population
35,000
Observed
Adjusted ABS Forecast
Rural Population
Population Served with Water
Sewered Population
30,000
25,000
20,000
15,000
10,000
5,000
0
1981
1991
2001
2011
2021
2031
Year
Figure 6-4 Population Served with Water and Sewerage Services
Figure 6-4 shows that currently 82% of the shire population are provided with reticulated
water from a Council-managed system. This figure also shows that 75% of the shire
population is currently serviced with Council’s reticulated sewer system.
6.3.4
Shire-wide Housing
When examining the water services needs, it is important to consider not only the number
of people but also the type of dwelling they live in. Analysis of the dwelling occupancy and
ownership information shows that during the 1996 census about 52% of the dwellings were
unoccupied and/or owned by people living outside the shire. The corresponding figures
from the 2001 census revealed an increase in the proportion of dwellings being occupied by
their owners. This shows that in addition to the growth in overall dwelling numbers, there
are a higher number of existing dwellings becoming permanently occupied. The graphs
below show the growth in new dwellings (Figure 6-5) and owner occupancy trends (Figure
6-6 and Figure 6-7) over the last few years.
40
Eurobodalla Integrated Water Cycle Management Strategy
25,000
Number of Dwellings
20,000
15,000
House
Flats/Apartments
Other Dwellings
All Dwellings
10,000
5,000
0
1990
1992
1994
1996
1998
2000
2002
Year
Figure 6-5 Historical Dwelling Growth
60%
% Holiday Dwellings
50%
40%
Holiday Houses
Holiday Semis and Flats
30%
Holiday Houses and Semis
Holiday Flats
20%
10%
0%
1981
1991
2001
2011
2021
2031
Year
Figure 6-6 Past and Future Holiday Dwellings as a Proportion of the Total Housing
Stock
41
Eurobodalla Integrated Water Cycle Management Strategy
80%
% occupied
separate houses
70%
% Occupancy
60%
% Occupied Semidetached, row or
terrace house,
townhouse, flat, unit
or apartment
50%
40%
% occupied
separate houses or
semis
30%
20%
% occupied flats
10%
0%
1985
1990
1995
2000
2005
Year
Figure 6-7 Historical Occupancy Levels
6.3.5
Residential Growth
Residential demand forecasts can be made by assessing rates and trends in demographic
factors such as population growth, the number and type of residential dwellings, occupancy
rates and dwelling consumption. The residential population in the Eurobodalla Shire has
grown over time (as shown in Figure 6-2). Growth is expected to continue in the future but
at a decreasing rate.
3.0
Household size occupied separate houses
Household Size
2.5
Household size Occupied Semi-detached,
row or terrace house,
townhouse, flat, unit or
apartment
2.0
1.5
Household size occupied separate houses
or semis
1.0
Household size Occupied flat, unit or
apartment
0.5
0.0
1981
1986
1991
1996
2001
2006
2011
2016
Year
Figure 6-8 Past and Future Household Size
42
2021
2026
2031
Eurobodalla Integrated Water Cycle Management Strategy
Dwelling occupancy (the number of people per dwelling) has steadily declined over time. It
is expected that occupancy ratios will continue to decline into the future, although the rate of
decline is predicted to be slower than in the past. Figure 6-8 indicates that the average
household size for flats, units or apartments is expected to decrease from 1.65 in 2011 to
1.61 by 2032. The dwelling occupancy ratios for houses and semis are also expected to
decrease from 2.3 in 2011 to 2.1 by 2032.
6.3.6
Data Accuracy
The various methods of data collection used in the past have resulted in a number of
discrepancies, making it difficult to determine the number of water accounts in Eurobodalla.
A house count was carried out in 2001 for the Batemans Bay Sewerage Strategy that
counted the number of dwellings connected to the Batemans Bay STP. In 2002 the
remaining towns and villages connected to the regional scheme were counted. As a
consequence there were dwellings in the Batemans Bay area connected to water but not
sewered that were missed through this data collection procedure. In addition future
projections were done at a reservoir zone level and did not consider houses supplied
through pressure reducing valves.
The house count data determined the number of flats in the shire. A query of the number of
bills sent out showed that there are over 1 000 more bills sent out each year than meters
read. This discrepancy is likely to arise from the vacant lots, which are billed the standing
charge but are not metered. Some blocks of flats have only a single meter for the building;
thereby a count of the meters underestimates the true number of flats. Records shows that
the current house count is 15 227, meter count is 16 364 and billing count is 17 357.
6.3.7
Tourist Impacts
The shire’s commitment to maintain the natural and scenic landscape, combined with the
mild climate and proximity to Canberra, makes the area a popular tourist and holiday
destination. Available data shows that on average 30% of the holiday/tourist
accommodation is occupied year-round. During the peak Christmas/New Year and school
holiday period, the majority of the holiday accommodation is occupied.
The varying peak tourist/holiday season load and the increase in the proportion of the
dwellings with owner occupancy poses a challenge for water infrastructure planning. The
aim is to minimise the provision of redundant infrastructure that is only utilised during peak
load periods without compromising the catchment and specific water services objectives.
Additionally, the IWCM strategies proposed in this plan need to be sufficiently flexible to
accommodate unforeseen increases/decreases in the predicted population trends.
6.4
Urban Water Management Issues
Urban water management issues are a consequence of population increase and the
associated urban development. It is expected that the current pattern of population growth
will continue to be concentrated along the coastal areas of the shire. Therefore it is likely
that current and future water cycle management impacts will reflect this pattern and be
confined mainly to these coastal areas.
43
Eurobodalla Integrated Water Cycle Management Strategy
6.4.1
Urban Water Use and Discharge – Past and Present
Urban Water Use
The current average water consumption of Eurobodalla’s urban population is about
5 300 ML/a. The majority of this water is disinfected with chlorine and is delivered through
Council’s regional water supply scheme. The water needs of the residents at Nelligen,
South Durras and Congo are met privately by roof rainwater and backyard bore water.
During periods of drought and prolonged low rainfall periods, the individual residents buy
their water from the regional scheme. Water service issues relating to each town and
village are discussed in more detail in part C.
Historical water usage records available since the mid-1980s for the regional scheme
suggests that the extraction of fresh water from the three rivers, namely Buckenboura,
Moruya and Tuross Rivers, has steadily increased with population growth. Records show
that in the past four years, the average annual water consumption (5 300 ML/a) serviced
through the regional scheme fluctuated by as much as 11% over the same period. These
fluctuations are due in part to climate effects and tourist numbers. Figure 6-9 below shows
the proportion of water extracted from the three river sources.
Yearly River Intake (ML)
6,000
5,000
4,000
3,000
B /B oura
Tuross River
Moruya
2,000
1,000
0
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
Year
Figure 6-9 Proportion of Water Harvested from Each River
Figure 6-9 shows that the majority of the urban water demand is supplied by Moruya River.
This correlates to the concentration of the shire’s population in the northern areas, and the
northerly location of the off-stream storage. With the regional scheme being reliant on the
Moruya River, urban water usage impacts on this river the most. The health of the river
environment is also particularly vulnerable during periods of low river flows, as in most
years low flow coincides with high urban water demand periods. Records show that the
current average daily water use by the regional scheme consumers is approximately
14.5 ML/d. This figure increases to 32 ML/d during the typical summer holiday period.
Figure 6-10 shows the current urban annual water consumption profile.
44
Eurobodalla Integrated Water Cycle Management Strategy
Urban Irrigation
0%
Industrial
0.70%
Institutional/Public
8.30%
Office/Retail
9.90%
Total Houses
Total Flats
Motel
Caravan Parks
6.70%
Caravan Parks
Office/Retail
Urban Irrigation
Motel
3.90%
Total Houses
62.30%
Industrial
Institutional/Public
Total Flats
7.80%
Figure 6-10 Urban Communities Water Consumption Profile
Figure 6-10 shows that the greatest proportion of urban water consumption is for residential
use (62%), followed by retail/office and institutional use. Further analysis of the residential
sector indicates that approximately 60% of water is used by permanent residents and the
remainder by tourists and/or non-resident ratepayers. Records for the last three years
indicate that the average annual consumption by permanent residents was approximately
576 kL/a per property, with a positive variation of 28% due to climate variation. Table 6-2
breaks residential water use into internal and external usage, and provides the quantity of
water used by each dwelling type.
Table 6-2 Internal and External Water Use by Dwelling Type
Dwelling Type
Permanent Houses
Holiday Houses
Permanent Flats
Holiday Flats
Use
% of Total
Dwelling Use
Volume
L/d/dwelling
Internal
76.5%
441.3
External
23.5%
135.6
Internal
82.1%
341.2
External
17.9%
74.4
Internal
79.2%
323.4
External
20.8%
84.9
Internal
84.3%
251.5
External
15.7%
46.8
The past consumption data (Figure 6-11) also shows that since the introduction of the ‘user
pays’ pricing model in 1993, average water usage per house, excluding climate influences,
has remained relatively stable. Although the average water consumption in Eurobodalla is
low compared to most other coastal communities in the state, given the climatic condition of
the area it is considered that there is scope to further improve water use through the
adoption of more water-efficient and conservation practices. Water efficiency measures and
conservation practices are discussed in part C.
45
Eurobodalla Integrated Water Cycle Management Strategy
2,500
Annual Volume (ML/Yr)
2,000
1,500
1,000
500
0
1990
1992
1994
1996
1998
2000
2002
Year
Permanent Houses
Holiday Houses
Figure 6-11 Historic Residential Demands
Records show that non-metered consumption supplied through the regional scheme
equates to an additional 16% (approximate) to the annual consumption. The reported
system loss rates are high in comparison to other NSW town water supply systems (DLWC
Performance Comparisons 2001)
Figure 6-10 shows that the industrial demand supplied by the regional scheme is small. Any
increase in future industrial water demand needs to be fulfilled by acquiring new
entitlements in the market and/or by accommodating growing industrial water needs within
the existing town water entitlements (see Water Management Act in section 6.1.1 for further
details).
Urban Water Discharge
Urban wastewater has increased with population growth and currently stands at
approximately 4 500 ML/a. Approximately 85% (3 820 ML/a) of wastewater produced in the
urban areas of Eurobodalla receives secondary treatment at one of the Council’s five
sewage treatment plants. Of the total secondary treated effluent, approximately 13%
(500 ML/a) is beneficially reused for irrigation at local golf courses and playing fields. The
remaining effluent is discharged to the ocean. On-site systems account for the remaining
15% of urban wastewater not treated at an STP.
The secondary treated effluent from four of the five plants undergoes passive or natural
disinfection prior to discharge. The effluent from the Moruya plant is artificially disinfected
using an ultraviolet irradiation plant before being discharged to the environment. The daily
average wastewater treated by the five plants is approximately 8 ML/d, and this volume
increases by approximately 20% during the peak holiday/tourist season.
Wastewater from the villages of Nelligen, South Durras, Congo, Mystery Bay, Rosedale,
Guerilla Bay, Bodalla, Potato Point, Central Tilba, Moruya Head, Turlinjah, Tilba Tilba and
Akolele receives minimal treatment through on-site systems. This system of wastewater
treatment represents a substantial risk to the local environment and the public health of the
community. Council is currently implementing measures to improve the quality of the
wastewater produced from Moruya Head, Turlinjah and Bodalla villages. Wastewater issues
relating to each town and village are discussed in more detail in part C.
The discharge of stormwater from the urban areas has also been increasing steadily with
population growth and the expansion of the urban footprint. At present approximately,
46
Eurobodalla Integrated Water Cycle Management Strategy
68 ML/a of urban stormwater is discharged to the environment, consisting of approximately
64 500 kg/a of total nitrogen and 8 500 kg/a of phosphorus (based on median year rainfall).
Testing of urban stormwater from other coastal towns and villages suggests that urban
stormwater also contains significant loads of sediment, litter, bacteria and other pathogenic
organisms. At present there is limited urban stormwater quality control and management,
and no beneficial reuse of stormwater. Continual urban development without considering
appropriate stormwater management options will result in the continual decline of
environmental water quality and represent an increased risk to public health. The
stormwater issues relating to each individual town and village are discussed in more detail
in part C.
6.4.2
Urban Water Use and Discharge – Future Predictions
Urban Water Use
The population of the Eurobodalla Shire is expected to increase by 50% over the next three
decades, with most of this increase being accommodated within the major coastal urban
centres, as either new subdivision or as infill development within existing residential areas.
This increase in population will correlate to a growing demand for water, and consequently
increase wastewater and urban stormwater volumes.
The future urban water demands have been projected using three approaches as follows:
!
Traditional approach
!
Contemporary approach
!
Demand Managed approach (see section 8.1 for details)
Traditional Approach – In this approach the water demands are projected by modelling
the individual end uses for a typical property and then extrapolating this per property
demand to the whole community. The model is then calibrated against actual metered
quarterly consumption by estimating the residential indoor demand and the seasonal
demand variations. Thus the only factor that is considered to affect demand is population
growth. Macoun (1999) used this approach to forecast the demands. The population
forecast used was based on the low population increase predicted by DUAP.
Contemporary Approach – In predicting the water demands using this approach,
consideration is given to the mandatory plumbing regulation governing the toilet cisterns
and the future availability of plumbing fixtures and devices, and household white goods.
Consideration is also given to Council’s current water conservation initiatives along with the
past climatic and economic influences on demands. The population growth rate used in
this approach incorporated the 2001 census and was lower than that used in the traditional
approach as discussed earlier. The demand projected using this approach is referred to as
‘baseline’ in Figure 6-12.
Figure 6-12. shows the predicted annual water demands until year 2032.
47
Eurobodalla Integrated Water Cycle Management Strategy
9,000
8,000
Demand ML/a
7,000
6,000
Historical Calender Year
5,000
Historical Water Year
Traditional
4,000
Baseline
3,000
Demand Management
2,000
1,000
0
1982
1992
2002
2012
2022
2032
Year
Figure 6-12 Forecast of Regional Schemes Average Annual Water Demand
The figure shows that the water demands predicted using the traditional approach is about
1000ML more than that predicted using the contemporary approach. Some of this extra
demand could be attributed to the higher population projection in the traditional approach.
Both the traditional and contemporary demand projection approaches assumes that the
current water use practices and behaviour will continue as at present and the demand
variation to climate and tourist inflow will also continue as at present. The Supplementary
Demand Report prepared by DLWC provides additional information and assumptions
relating to contemporary demand forecast approach used for this study.
Figure 6-14 and Figure 6-13 shows the regional schemes current and future average
annual and peak day water demand splits between the northern, central and southern
urban areas.
48
Eurobodalla Integrated Water Cycle Management Strategy
8,000
7,000
Water Consumption ML/yr
6,000
5,000
north
central
south
Total
4,000
3,000
2,000
1,000
0
2000
2005
2010
2015
2020
2025
2030
2035
Year
Figure 6-14 Split of the Average Annual Regional Demands by Area – Contemporary
Approach
50
45
40
Demand (ML/d)
35
30
Total
25
North
Central
20
South
15
10
5
0
2000
2005
2010
2015
2020
2025
2030
2035
Year
Figure 6-15 Peak Day Demand Forecast – Contemporary Approach
49
Eurobodalla Integrated Water Cycle Management Strategy
Figure 6-14 shows that the northern, southern and central areas are all expected to
experience growing urban water demands, with the northern area likely to be the greatest
contributor to the regional scheme’s demand increases. Similarly, Figure 6-15 shows that
although all regions are expected to experience growing daily water demands, it is the
northern area that is anticipated to experience the greatest rate of increase.
Figure 6-16 shows that as a proportion of total residential demand, flats/units will increase
from 15% to 28% and the separate house demand will decrease from 85% to 72%.
4,500
Annual Volume (ML/Yr)
4,000
3,500
3,000
Residential Houses
2,500
Holiday Houses
Residential Flats
2,000
Holiday Flats
Total
1,500
1,000
500
19
90
19
92
19
94
19
96
19
98
20
00
20
02
20
04
20
06
20
08
20
10
20
12
20
14
20
16
20
18
20
20
20
22
20
24
20
26
20
28
20
30
20
32
0
Year
Figure 6-16 Forecast of Regional Schemes Residential Demands
In the absence of specific future development proposals it has been assumed that
commercial and institutional water use will increase in line with residential demand. Further,
the above forecasts assume that non-metered usage will remain steady at about
67 L/d/capita. Non-metered usage is the difference between total supply and total metered
consumption. It comprises:
!
Meter inaccuracy
!
Authorised non-metered usage
!
Leakage
!
Breaks, and
!
Regular mains flushing to maintain the integrity of the delivery and distribution
system.
Urban Water Discharge
In the next three decades wastewater produced by the shire’s urban community is expected
to increase by 30% from 4 500 ML/a to 5 850 ML/a. It is expected that the average daily
wastewater volume to be treated in the future by the seven treatment plants will be
approximately 11.2 ML/d, with an increase of approximately 20% during the peak
holiday/tourist season. Based on current information, it is expected that about 5 150 ML/a
(88%) of the future wastewater flow would be treated at the seven treatment plants in
Eurobodalla to a secondary standard before discharge to the environment. The expected
increase in wastewater production requires appropriate management to ensure that the
local environment and community health is not compromised. The opportunities available to
further enhance the quality of the secondary treated effluent to increase its beneficial reuse
is discussed in part C. Also discussed in part C is the best practice management and
treatment standards for wastewater produced in the unsewered villages.
50
Eurobodalla Integrated Water Cycle Management Strategy
The volume of urban stormwater discharge will increase with the release and development
of new urban subdivisions. Analysis indicates that if Council continues with its current urban
stormwater management policy and practices the increase in urban stormwater quantity
and quality discharge would be in the order of 20-30% more than current levels. These
increases, if not managed adequately, will further impact on the local environment and may
pose public safety issues. The opportunities available to further enhance the quality of
stormwater discharges and to increase the potential for beneficial reuse is discussed in
part C.
6.5
Infrastructure Performance Issues
The Eurobodalla water service system faces a number of infrastructure performancerelated issues that need to be addressed in this IWCM strategy.
6.5.1
The Regional Water Supply
Description of Existing Scheme
The regional scheme harvests run-of-river flows from the Buckenboura, Moruya and Tuross
Rivers. The water harvested from the Moruya and Tuross Rivers is fed directly into the
reticulation network after disinfection with chlorine. Excess water from the Moruya River
and water from the Buckenboura River is stored in the Deep Creek Dam off-river storage.
The dam has a capacity of 4 900 ML and maintains supply during drought conditions and
during low and turbid river flow periods. The water from each source can be transferred
along the coast from Long Beach in the north to Mystery Bay in the south.
The Buckenboura River, a tributary of the Clyde River has historically been an unreliable
water source that has failed during several periods of drought. The Buckenboura River
supply infrastructure consists of a concrete weir across the river and a pumping facility with
a single pumping capacity of 2.9 ML/d and a parallel operating capacity of 4.8 ML/d.
The Moruya River is the main source of supply to the regional scheme. Harvested run-ofriver flows are normally supplied to the communities situated between Long Beach in the
north and Tuross Head in the south. Despite no surface flows during the droughts of the
1980s and 1990s, limited extraction was feasible to maintain emergency supply. The
Moruya River supply infrastructure consists of a low and high head pumping facility with a
transfer capacity of about 16.4 ML/d.
The Tuross River is the main source of supply to the southern section of the regional
scheme from Bodalla to Mystery Bay. Despite no surface flows during the droughts of the
1980s and 1990s, limited extraction was feasible to maintain emergency supply. The
Tuross River supply infrastructure consists of a low and high head pumping facility with a
transfer capacity of about 6.7 ML/d.
The Quality of the Source Waters
Council routinely monitors the water quality of the supply sources and the distributed water
at strategic locations. This routine monitoring is carried out in accordance with the NSW
Health quality assurance requirements under the Public Health Act 1991, to monitor long
term trends and for operational and emergency response management.
In 1997 Council undertook a comprehensive water quality monitoring program over a
twelve-month period. The aims of this study were to:
!
Better understand the seasonal variation of the water quality from the various
sources
51
Eurobodalla Integrated Water Cycle Management Strategy
!
Examine the performance and adequacy of the barriers and management
procedures in place to minimise the supply of poor water quality
!
Determine the water quality parameters that frequently exceed the failure criteria
and the consequences of these failures.
The Australian Drinking Water Quality Guidelines were used as the failure criteria when
assessing the medium to long term consequences and service provision risk.
The study found that the water quality of the supply sources is influenced by weather
patterns and activities in the catchment. It concluded that whilst the combination of
management procedures and barriers are effective in reducing the supply of poor water
quality, they do not meet the current best management practice standards.
Security of Supply
Security of supply is a measurement of the reliability of the water supply headworks; in this
case the source rivers and the dam, particularly during drought periods. Supply security is
considered to be adequate when reasonable customer demands can be met on most
occasions without restrictions.
The NSW Government has defined ‘secure yield’ as the maximum supply rate that can be
maintained by the supply system without exceeding any one of the following three
acceptability criteria (NSW Government, Water Supply and Sewerage Management
Guidelines, 1991):
!
Reliability – The proportion of the supply that is unrestricted. Over any extended
period, restrictions should not be in place for more than 5% of the time. In
Eurobodalla for example this would mean that based on 100 years of stream flow
the total duration of water restrictions would be less than 60 months.
!
Robustness – The average frequency of restriction should be less than once every
10 years. More precisely there would be less than a 1-in-10 chance of having to
impose restrictions in any one year.
!
Security - The storage will not be drawn down to below a critical level that would
prevent Council providing even a basic supply or require alternative supply
measures. The IWCM strategy guards against this scenario by ensuring that the
system can supply 80% of unrestricted demand from the time restrictions are
imposed. This is based on the conservative assumption that the full drought of
record could recommence at this time.
The above three acceptability criteria are commonly referred to as the 5/10/20 rule. Implicit
in this rule is the trade-off between risk, community costs and social expectations. This rule
was developed and adopted by the NSW Government in the mid-1980s and has since been
used in the water supply planning for nearly all country towns in NSW. Although the IWCM
strategy guards against storage levels being drawn down to a critical level by ensuring that
the system can supply 80% of unrestricted demand from the time restrictions are imposed,
this margin will reduce over time with aggressive demand management.
The calculation of secure yield requires modelling of the water supply source and system,
which is related to the following:
52
!
Weather pattern in the water supply catchment and the urban areas
!
The environmental needs of the rivers including access sharing rules with other
water users
!
The quantity of water that can be stored
Eurobodalla Integrated Water Cycle Management Strategy
!
The rate of storage depletion during drought and filling after drought
!
The ability to conserve water during drought
Setting the security of supply standard defines the yield of the system, and consequently
the future supply infrastructure provision requirements. For a given level of demand
reduction there is a trade-off between the setting of security of supply standards and the
timing and extent of supply source development.
At one end of the spectrum, an attempt to ‘drought proof’ the regional scheme would incur
considerable capital expenditure and environmental costs, while at the other end insufficient
supply source infrastructure will put the Eurobodalla community at increased risk of running
out of water, with associated economic and social impacts. The 5/10/20 rule aims to
achieve this balance and allows the comparison of different systems. The rules allow a
system to be developed that would provide sufficient storage and management of water
supply through a worse drought than on record. Management during a drought would be
assisted by Council’s restriction policy. Whatever drought it is designed for there is always a
statistical possibility of a worse drought occurring.
The Eurobodalla Shire’s restriction policy aims to maintain a balance between minimising
the frequency of restrictions and maximising the duration that stored water can be made to
last in a drought. The key steps in Council’s current restriction policy are:
Level 1 Restrictions
Level 1 restrictions are implemented when the Deep Creek Dam storage level falls below
80% and supplies from the rivers are no longer practical or very limited.
There is a ban on the use of fixed watering devices such as sprinklers (including pop-ups)
and unattended hoses with the exception of:
!
Hand-held hoses
!
Micro and drip irrigation systems
!
Bowling and golf club greens
!
Commercial market gardens and nurseries
!
Turf wickets available to the general public
!
Public or commercial swimming pools and essential areas.
Level 2 Restrictions
Level 2 restrictions are implemented when Deep Creek Dam storage level falls below 70%
by volume.
There is a complete ban on the use of fixed watering devices such as sprinklers (including
pop-ups) and unattended hoses with the exception of:
!
Bowling and golf club greens
!
Commercial market gardens and nurseries
!
Turf wickets available to the general public
!
Public or commercial swimming pools
53
Eurobodalla Integrated Water Cycle Management Strategy
!
Essential areas (for reasons such as public health) with the concurrence of the
Water and Waste Manager.
Spring loaded taps are to be installed at boat ramps.
Micro irrigation systems and hand-held hoses for garden watering and other external uses
including motor vehicle, boat washing and supply to private swimming pools are restricted
to a total of a 60-minute period between the hours of 6.00am and 8.00am or 5.00pm and
8.00pm daily. Hand-held hoses are to be limited to one hose per property, and washing
down of driveways and footpaths is not permitted, except by bucket.
Businesses such as car yards, public passenger bus services, taxi companies and other
organisations, required under regulations of the RTA to keep vehicles in a clean state, are
restricted to washing vehicles between the hours of 10.00am and 12 noon daily.
Level 3 Restrictions
Level 3 restrictions are implemented when water can only be drawn from Deep Creek Dam
and its storage level falls below 50% by volume.
The restrictions are as per Level 2 with the permitted time reduced to a total of 30 minutes
between the hours of 6.00am and 8.00am or 5.00pm and 8.00pm. Permissible days are
reduced to Tuesdays, Thursdays, Saturdays and Sundays.
Businesses such as car yards, public passenger bus services, taxi companies and other
organisations, required under regulations of RTA to keep vehicles in a clean state, are
restricted to washing vehicles between the hours of 10.00am and 12 noon daily on
Mondays, Wednesdays and Fridays.
Level 4 Restrictions
Level 4 restrictions are implemented when water can only be drawn from Deep Creek Dam
and its storage level falls below 40% by volume.
There is a complete ban on the use of running hoses or taps for any external purpose, with
no exemptions. Water is available for domestic use only and essential areas (for reasons of
public health).
Restrictions after the Drought has Broken
The restrictions will remain in force depending on the storage levels in Deep Creek Dam to
allow the water supply system to replenish the dam at maximum capacity.
1.
Deep Creek Dam volume is less than 50% - Level 2 restrictions to be applied.
2.
Deep Creek Dam volume is between 50% and 70% - Level 1 restrictions to be
applied.
3.
Deep Creek Dam volume in excess of 70% and level rising - no restrictions to be
applied.
Modelling of the Regional Scheme
The regional scheme was modelled using the last 104 years of daily stream flow sequence
up to 2001, the above security of supply criteria and the current supply extraction licence
conditions. The modelling shows that the existing supply infrastructure can maintain an
annual supply of 8 200 ML/a (i.e. secure yield of 8 300 ML/a). This supply rate is far in
excess of the current annual demand of 5 300 ML, however Council’s operating strategy
limits run-of-river pumping during turbid stream flow periods (as this results in water being
supplied to the consumer that does not meet the ADWG for turbidity). This limitation on
54
Eurobodalla Integrated Water Cycle Management Strategy
pumping effectively reduces the security of supply resulting in more frequent restrictions
than predicted (3 times in the past 15 years compared with modelling parameters of 10
restrictions every 100 years). A filtration plant would eliminate the need for turbidity limit on
run-of-river pumping and would restore the original secure yield under the current licence
conditions. The current licence condition allows all the water available at the intakes to be
extracted to meet the urban demands. As a result there is no explicit protection of the
downstream environment and water users particularly during low flow periods. However, in
recognition of the social and environmental values, Council generally tends to cease
pumping when flows in the rivers are low. This has also contributed to lower supply security
and more frequent restrictions than the model suggests, which is based only on the licence
condition.
Current Security of Supply Status
Figure 6-17 shows that the secure yield of the existing scheme based on the current licence
conditions is about 8 200 ML/a. Based on population projections, the existing system of
source infrastructure is adequate to supply demand for the next 40+ years. However, due to
Council’s operating strategy, which limits extraction when the river water is turbid and
protects low flows by ceasing to pump, the actual secure yield is likely to be substantially
less. Due to the lack of operational turbidity data the secure yield based on the current
operational strategy cannot be accurately quantified at this stage.
Whilst the above observations are based on system modelling outcomes, in the
development of the model care has been taken to ensure that it represents the actual
situation as far as practical. There are still areas of uncertainty, and in developing the model
the following assumptions have been made:
!
Extraction is not constrained by water quality of the supply sources (e.g. turbidity)
!
The accuracy of the system modelling outcome is limited by the extent and
accuracy of the last 104 years of historic stream flow and rainfall data used
!
Any changes to catchment land use and irrigation practices will not significantly
alter the stream flow sequence
!
Future climate will be statistically similar to the observed historic climate
!
Future urban water use pattern will be statistically similar to observed historic usage
patterns and that the current legislation and community ‘consciousness and
awareness’ on conservation will continue
!
The population of Eurobodalla will continue to increase albeit at a slower rate than
in the past and that it will remain a popular tourist and holiday destination.
Environmental Flow and Access Sharing
As discussed in section 6.1.1, the Water Management Act will affect how much water is
available for harvesting during low flow periods. Leaving water for the river environment will
improve the environmental health and the long term sustainability of the river, however it
also reduces the secure yield of the water supply system. The quantity of water required for
the environmental flows has yet to be decided by the water management committees. At
the inter-agency meeting (October 2002) it was agreed that the future planning should
consider the following cease to pump and flow access conditions as the base level cases
for the three supply sources:
!
Within the first 10 year cycle of the water sharing plan, cease to pump when
Moruya, Tuross and Buckenboura Rivers flow drops below 12 ML/d, 17 ML/d and
th
1 ML/d respectively at the water supply intake (95 percentile).
55
Eurobodalla Integrated Water Cycle Management Strategy
!
In subsequent reviews of the water sharing plans the cease to pump level may be
th
conservation and an 80 percentile cease to pump level should also be evaluated.
!
In both the above cases, when flow is above the cease to pump level, maximum
water extracted by all users should not exceed 30% of the total flow.
!
All local runoff from the catchment of the Deep Creek off-river storage will be
retained in the storage.
Figure 6-17 shows the impact of the proposed 95/30 licence conditions on the secure yield
of the regional scheme.
9,000
8,000
Consumption ML
7,000
6,000
Historical Annual Demands
5,000
New Baseline
4,000
With Demand Management
3,000
Current Secure Yield
2,000
Secure Yield with 95/30
access
1,000
0
1980
1990
2000
2010
2020
2030
2040
Year
th
Figure 6-17 The Effect of a 95 Percentile 30% Access Licence Condition on Secure
Yield
Figure 6-17 show that through incorporating the 95/30 supply constraints, the existing
system of source infrastructure is adequate to supply the demand for the next few years,
beyond which an increase in supply transfer rate and storage is required to supply the long
term demands.
Figure 6-18 presents the impact of the 80/30 conditions on the secure yield of the regional
scheme. This graph shows that the implementation of the 80/30 supply constraints would
significantly reduce the secure yield below the current demands necessitating an immediate
expansion to the transfer rate and storage capacity.
56
Eurobodalla Integrated Water Cycle Management Strategy
9,000
8,000
Consumption ML
7,000
6,000
Historical Annual Demands
5,000
New Baseline
4,000
With Demand Management
Current Secure Yield
3,000
Secure Yield with 80/30
access
2,000
1,000
0
1980
1990
2000
2010
2020
2030
2040
Year
th
Figure 6-18 The Effect of an 80 Percentile 30% Access Licence Condition on Secure
Yield
From this analysis it is concluded that alteration to the current licence conditions to formally
incorporate low flow and percentage of total flow protection will reduce the ability of the
existing system of source infrastructure to supply demands in the future. To meet this
source infrastructure shortfall, water conservation and supply development strategies are
outlined in subsequent chapters. These measures together will maintain security of supply
during drought while catering for population growth and development.
6.5.2
Sewage Treatment Issues
The following is an overview of the sewage treatment issues in the Eurobodalla Shire.
!
The Batemans Bay sewerage system is under stress and experiences sewage
overflows from the sewer network
!
Odour complaints
!
Pollution reduction programs (PRPs) have been issued for Moruya and Batemans
Bay STP
!
Unsewered villages in sensitive areas pose a significant environmental and health
risk
!
Sewerage systems are vulnerable to power blackouts
!
Lack of storage and detention within systems
!
Peak loads in tourist/ holiday season becoming longer duration as retirees settle.
57
Eurobodalla Integrated Water Cycle Management Strategy
6.5.3
Stormwater Issues
The Eurobodalla Shire Stormwater Issues and Management Opportunities (Ref. 3) report
has identified the main stormwater issues in the Eurobodalla area (Appendix W). A
summary of these issues is given below.
58
!
Aging pipes and incomplete network causing localised flooding
!
Impact of occasional sewer overflows on stormwater quality
!
Nature and state of the infrastructure is unknown
!
Poor quality stormwater is affecting water quality
!
Discharges to SEPP 14 wetlands
!
Stormwater flooding
!
Stormwater inflows into sewer system.
Eurobodalla Integrated Water Cycle Management Strategy
Part C
How Do We Fix the Issues
This Part develops solutions to the issues. Solutions
are developed at regional, local and shire-wide level.
59
Eurobodalla Integrated Water Cycle Management Strategy
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Eurobodalla Integrated Water Cycle Management Strategy
7 Part C Introduction
In this part, the ‘how to fix’ or in other words ‘how to get to where we want to be’ question is
considered and addressed using the IWCM concept.
Since the urban areas are distributed and the issues are unique to each area, this requires
unique solutions to meet the aspirations and demands of each community and the local
environment. There is a need to consider the ‘how to’ at both the regional and local levels.
The IWCM options identified at both levels are then combined to form shire-wide scenarios.
Accordingly, this part of the report evaluates opportunities at both the regional and local
levels, and then provides the shire-wide solutions.
It is important to realise that the ‘how to’ could be achieved in a number of ways which do
not necessarily rely solely on the provision of new infrastructure. Other measures include
non-build management opportunities. Thus the ‘how to’ consists of both structural and nonstructural solutions.
In assessing the opportunities and options available, a triple bottom line (environment,
social and economic) ranking was used as part of the balanced outcomes planning. For
each of the opportunities and options identified, a score ranging from 0 to 3 has been
assigned. A score of 0 is representative that the opportunity does not meet the criteria, and
a score of 3 means that the opportunity is well suited to achieving the objectives of the
criteria.
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Eurobodalla Integrated Water Cycle Management Strategy
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Eurobodalla Integrated Water Cycle Management Strategy
8 Regional Water Cycle Management
Opportunities
8.1
8.1.1
Opportunities for Managing the Regional Water Demands
Status of Current Measures
Eurobodalla has made significant gains in water conservation and demand reduction. For
example:
8.1.2
!
The ‘user pays’ pricing and community awareness programs have resulted in the
household water consumption being on average 20-30% lower than many other
coastal towns in NSW.
!
About 10% of the total reclaimed water produced is recycled.
!
Planning and building controls that actively promote energy efficiency have also
significantly contributed to lower water consumption and the reduction of
greenhouse gas emissions.
Introduction
Whilst the current demand reduction measures have been successful in reducing per capita
water consumption, the annual water consumption will continue to grow as the population
increases resulting in environmental impacts. The community and Council together have
the opportunity to develop further strategies at their own discretion to slow the growth in
water consumption. It is important to note that in order to protect and sustainably manage
the water resources for the future, Eurobodalla would need to continue a sustained pursuit
of a multi-faceted approach to water conservation and demand reduction.
Recommended water conservation and demand reduction programs to be implemented by
Council should include elements such as, water demand reduction through appropriate
planning controls, improved water efficiency, increasing water conservation awareness
through promotion and education, distribution system loss reduction, pricing, urban water
harvesting and water recycling. Effective initiatives are also required to ensure sustainable
commercial growth as increased future commercial water requirements will not be
accommodated for by the new licensing regime under the Water Management Act.
It is crucial that these efforts be sustained and the benefits achieved a decade in advance
of future supply augmentation decisions. The best way to ensure that any water
conservation strategy undertaken will provide long term results is for Council to make a firm
commitment to the program. This commitment may take many forms, some of which
include providing an upper level Council policy covering water conservation, providing
adequate staffing resources and making funds available to implement and effectively
monitor the program options, and including Council’s operations as an integral part of the
program.
The specific staging of the individual options may change depending on the uptake levels
and demand reductions achieved by the water conservation strategy. Therefore it is
important that Council provide resources to monitor the effectiveness of measures that
have been implemented. The direct effects of some components of the demand
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Eurobodalla Integrated Water Cycle Management Strategy
management program such as the education campaign will be difficult to quantify in
isolation of concurrently run measures.
The main advantage of water conservation measures from both the residential and nonresidential sector is the downsizing and deferral of future water supply augmentation costs.
There are also benefits by way of reduced annual operating costs for water treatment and
distribution and reduced annual operating costs for wastewater collection, treatment and
recycling. Some water conservation measures will also reduce household energy bills.
8.1.3
Planning Controls
During the community consultation period, several of the villages were opposed to the
provision of reticulated water and sewerage services as it is seen as a means to facilitate
medium density development. However strategic planning via environmental planning
instruments (EPIs) offers a means by which to regulate development and ensure that it is
undertaken in a sustainable manner. The preparation of EPIs is a transparent process,
which encourages community participation and review. Limiting development should
therefore be effectively achieved through planning controls such as zoning, rather than
limiting the provision of water and sewerage services.
Eurobodalla Council has addressed the energy efficiency of residential housing in its
Residential Design and Development Guidelines Development Control Plan (Ref. 3). The
DCP contains specifics on the energy efficiency and the associated greenhouse gas
emissions for various elements of residential housing. This includes hot water systems,
however the efficiency of water using appliances and practices that affect other areas of the
water cycle such as water sensitive urban design are not specifically covered.
Planning Control Opportunity
Water Efficiency
There is scope for Council to include water efficiency clauses in the Residential Design and
Development Guidelines DCP because in many instances water efficiency indirectly
promotes energy efficiency. For example the installation of AAA rated shower heads and
energy efficient clothes washing machines will reduce hot water consumption and thus
energy consumption. The inclusion of other water efficiency measures such as low flow
dual flush toilets and the planting of drought-resistant native plant species for households
may portray a greater water conservation message in the Residential Design and
Development Guidelines DCP.
Council has the opportunity to increase water efficiency in new residential dwellings by
including specific clauses in this DCP that cover minimum performance standards for all
water using fixtures. Water efficient appliance and fittings such as water efficient shower
roses and aerated taps with Aqualoc tap valves or similar can be installed in new houses at
little or no extra cost. Some measures are already included in the local Eurobodalla Shire
building code and inclusion in development control plans has been proposed.
Water-Sensitive Urban Design
Water-sensitive urban design (WSUD) incorporates both the temporary and permanent
storage of stormwater to reduce the peak flow velocity and the volume of water leaving the
urban environment. It aims to keep the balance between infiltration and runoff from the
urban allotment as close as possible to the pre-development balance. Typical urban
designs increase stormwater runoff by 30% or more due to the addition of impervious
surfaces to the landscape. Better control of the flow and retention of stormwater in the
urban landscape can reduce garden water and landscape water needs at little or no extra
cost. Techniques to reduce flow velocities and volumes from the block can be achieved
through the use of rainwater tanks, natural filtration, surface storage and infiltration into
aquifers. The benefit of incorporating WSUD in new developments extends beyond solely
64
Eurobodalla Integrated Water Cycle Management Strategy
reducing the pressure on drainage systems, with WSUD able to achieve a significant
reduction in the volume of pollutant loads entering the environment.
Thus to gain maximum benefit from this opportunity the Residential Design and
Development Guidelines DCP is extended to cover the following elements as a minimum:
!
AAA water efficient appliances including low flow shower heads, 6 L/3 L dual flush
toilets and aerated taps
!
Elements of water-sensitive urban design
!
Rainwater tanks plumbed for garden watering, toilet flushing and washing machine
use (see Appendix Z on roofwater harvesting), and
!
Site runoff and nutrient loads limited to less than 5% of undeveloped runoff (in
accordance with Draft Strategic Business Objectives in Appendix A).
This opportunity assists Council in meeting its Draft Strategic Business Objectives
(Appendix A) of 100% of development proposals incorporating water resource conservation
concepts.
8.1.4
Water Conservation Education
Promoting the water conservation message through current Council educational programs
has raised the community’s awareness to important water related issues. This awareness
has been heightened by the low storage levels and water restrictions that currently exist
within Eurobodalla Shire and other areas of NSW. The challenge for Council is to ensure
that this increased awareness is translated into lasting behavioural change of customers’
patterns of water use. Residential outdoor water use, which includes garden watering, car
washing, hosing down of hard surfaces and the filling of swimming pools is one area that
has the potential for significant water savings from improved customer education. Changing
the wasteful outdoor water practices of permanent residents and tourists and holidaymakers alike is a key goal of a water conservation education campaign. Further
opportunities to enhance the water conservation message include increasing community
involvement at a local level, targeting specific groups within the community with specially
tailored sessions and promoting the Standards Australia Water Conservation Rating and
Labelling Scheme for water-using appliances.
Water Conservation Education Opportunity
Target Groups
Experience elsewhere shows that generic efficiency programs targeting all customer
categories are not as effective as programs that specifically target a portion of the
community. The residential sector is the largest collective water user within the Eurobodalla
Shire. Therefore an effective program that specifically addresses domestic water-efficient
appliances has probably the greatest capacity to produce significant savings in water use.
Opportunities are also available to reduce the demands for non-residential users by tailoring
efficiency programs based on the type of industry and the customer’s specific water use.
The community is in a key position to become actively involved in the development of water
conservation programs. Incorporating valuable community knowledge is advantageous in
many respects, but perhaps the greatest benefit is the sense of ownership that the
community can claim for programs that they have helped develop. This in turn will lead to
increased uptake levels for any programs that are implemented and therefore improved
results.
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Eurobodalla Integrated Water Cycle Management Strategy
While Council has implemented many educational programs aimed at schools and the
general community, it is recommended that Council develop programs that specifically
target other groups.
!
Builders and plumbers are one such group that will provide extra benefits to the
overall results of a water savings program. Specifically targeting builders and
plumbers as part of a water conservation education program will yield benefits
because of their technical knowledge and the personal contact that they have with
home owners. They are also independent of Council’s operations and provide
another avenue to spread the water conservation message.
!
Architects, landscape gardeners, nursery owners and property developers can also
play an important part in conveying the message of water conservation to new and
existing home owners if they are targeted appropriately. Hunter Water, in
conjunction with the Master Builders Association, has implemented the EcoBuild
advisory service for both building professionals and residential customers, which
provides information regarding water conservation technologies to incorporate into
new or existing dwellings.
!
Council staff can also be targeted for special education sessions that cover watersaving practices both at work and in the home. This will have the benefit of directly
reducing Council’s water use but will also provide a positive example to friends and
neighbours of staff members. Tourists and holiday-makers represent another group
that Council should consider targeting with a specific education campaign. The
influx of tourists, predominantly during the hottest months of the year when peak
demand is at its greatest, represents a significant contributor to excessive water
usage.
Labelling of Water-Efficient Appliances
The Standards Australia Water Conservation Rating and Labelling Scheme is a national
initiative that is designed to provide an easy to understand rating system for the efficiency of
domestic water-using fixtures. The scheme provides each appliance with a rating of either
‘A’, ‘AA’ or ‘AAA’ in a scale of increased water efficiency. This allows customers to make
more informed decisions when purchasing water-using appliances.
As public awareness regarding water conservation issues improves and new technologies
become available, it is assumed that customers will be more prepared to alter their water
usage practices so that overall consumption is reduced.
Garden Watering and Other Outdoor Water Uses
Improved garden watering practices has the potential to produce significant water savings.
Areas of garden watering that are available to ESC to target include higher efficiency
watering systems, appropriate watering times, and planting drought-resistant species and
appropriately landscaped gardens.
Studies have shown that households that use fixed watering systems consume up to 35%
more water than the average household does. A study into outdoor water use in Canberra
conducted by the CSIRO estimated that watering the garden only twice a week would result
in a 25% saving in outdoor water consumption. Also, using a tap timer would provide a 20%
saving and installing a drip system would yield a 10% saving in outdoor water usage. New
technologies are available on the market that are less water intensive than existing
methods of watering such as sensor-controlled systems that only water the roots of plants
once the soil moisture reaches a set value.
Watering gardens in the early morning and evening will reduce evaporation as well as
keeping grass at a reasonable length rather than very short. Using hand-held sprinklers for
garden watering uses less water than automatic and fixed sprinkler systems and has the
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Eurobodalla Integrated Water Cycle Management Strategy
added advantages of better coverage and being able to reduce waste by better targeting
the actual garden area to be watered.
More appropriate gardens and landscaping also reduce water usage. Drought-resistant
native flora species, converting lawn areas that require large amounts of water to mulch
and altering watering habits will also reduce external water demand. Home owners who
water their lawns less regularly force the root system to grow deeper into the soil and thus
be more efficient at extracting moisture from the soil.
While garden watering is the major component of residential outdoor water consumption,
car washing, hosing down of hard surfaces and filling swimming pools collectively also
represent significant water use. Because of many wasteful practices in this area there is
considerable scope to reduce water consumption from these end uses through a water
conservation education program.
Washing cars with a bucket rather than with a hose, sweeping hard surfaces rather than
hosing down and keeping swimming pools covered to reduce evaporation losses are all
improvements to outdoor water usage practices that can be relayed to customers through
the education program. Washing cars over grassed areas rather than on hard surfaces will
also have benefits for the stormwater drainage system.
Water Audit and Retrofit Program
A retrofit program (discussed in Section 8.1.5 and 8.1.6) coupled with a water audit can
form an important component of the information provided to customers in an education
campaign. Conducting a water audit by a suitably experienced officer provides a face-toface contact that is important in delivering the water conservation message. Water audits
can be carried out for both residential and non-residential customers, however the water
usage assessment will change for different non-residential industries.
The officer will provide an assessment of each customer’s current water use and the
efficiency of existing water-using appliances. This will allow recommendations to be made
as to how the customer can further reduce water consumption. It is also important to
emphasise the dollar savings that are available to customers who implement the
recommended water conservation measures, in addition to the benefits to both Council and
the environment,. The costs and benefits of this part of an education program are included
in the retrofit program rather than as part of the water conservation education opportunity.
Water Conservation Education Costs
An allowance of $50 000 per annum for the first 4 years and $25 000 per annum for the
subsequent 4 years and then $10 000 per annum thereafter has been made for the
development and implementation of a coordinated water conservation and education
program incorporating the measures discussed above. It is estimated that this program
could save 0.57 ML/d. Ideally a coordinator would be employed to manage the education
program, or alternatively hire consultants with marketing and PR experience in running
similar programs. Having an ESC staff member manage the education program and the
overall demand management strategy would provide better control and results.
Demonstration House
Another important component for ESC to consider in improving the efficiency of water use
and as part of an education campaign is a water-efficient demonstration house. This would
provide practical, easy-to-use and inexpensive examples of water-efficient appliances that
customers can implement in their own homes. New technologies that reduce the water
consumption for both internal and external end uses should be included in the
demonstration house.
To help offset the capital costs associated with building the demonstration house,
sponsorship can be sought from companies with water-efficient products, which would allow
67
Eurobodalla Integrated Water Cycle Management Strategy
their products to be used and provide exposure to home owners. A whole range of more
sustainable solutions could be included in the demonstration house such as improved
energy efficient appliances, which would yield greater sponsorship opportunities. The costs
involved with a demonstration house would be significant and any undertaking would need
to be thoroughly assessed by ESC before commencement.
8.1.5
Residential Water Efficiency Program
Current and Future Residential Water Consumption
In section 6.4.1 the current water use in the shire was examined. Figure 6-10 showed that
the residential water consumption accounts for 70.1% of the total shire usage, therefore a
program to target residential water usage is recommended.
Average Water Consumption (L/Dwelling/day)
Figure 8-1 shows the daily residential end uses for an average household for 2002 and how
they have been modelled to change by 2032.
180
160
140
120
100
2002
2032
80
60
40
20
0
Toilets
Baths
Showers
Taps/Sinks Dishwashing
Laundry
Internal
Leakage
Outdoor
Residential Water Use
Figure 8-1 Typical Residential Water End Uses for 2002 and 2032 with natural
propagation of water efficient appliances
Figure 8-1 above shows that on average, in excess of 80% of the water used in households
may be attributed to showering, garden watering, clothes washing and toilet flushing. Any
program to reduce residential water consumption should therefore target these areas. The
figure also shows how the typical residential water uses will change over the planning
horizon due to the natural propagation of water-efficient appliances such as toilets, shower
heads and clothes washing machines. It can be seen that the toilet demand will significantly
reduce between 2002 and 2032. The water consumption for both shower roses and clothes
washing machines will also fall over this period but to a lesser extent. The reason for the
significant fall in water demand for toilet flushing is due to the mandatory installation of
water-efficient dual flush toilets through plumbing codes. The installation of other watersaving fixtures however is governed by consumer choice and market forces.
68
Eurobodalla Integrated Water Cycle Management Strategy
Active Retrofit Opportunity
Rather than wait for the natural propagation of water-efficient appliances to occur over time
as old models are replaced, ESC have the option to speed up this process through an
active residential retrofit program. This program involves retrofitting existing houses, rather
than new dwellings, with water-using appliances and fittings of increased water efficiency.
This usually involves replacing the appliance before it has worn out. Therefore financial
incentives are often required from the water utility to encourage customers to install more
water-efficient appliances in the home. New technologies to reduce outdoor water usage
such as drip sprinkler systems and soil moisture sensors that control the operation of
automatic sprinkler systems are now available on the market, however financial incentives
may also be needed to increase sales.
Implementation
As part of this strategy study, a preliminary analysis has been carried out. However, before
a retrofit program is undertaken a detailed demand management strategy is required to
determine the most cost effective retrofit program. Rather than simply increasing the
quantity of efficient end use fixtures over the whole shire, different residential customer
groups can be targeted depending on their water consumption habits. Home owners with
substantial areas of lawn and garden, and especially those who live in new subdivisions
with newly established gardens, can be targeted for outdoor education and financial
incentives. Pensioners who live in older houses can be targeted for retrofitting of low flush
volume toilets or cistern displacement devices and tap aerators. All state housing dwellings
can be included in an indoor retrofit program and include tenants in an outdoor water use
education campaign.
From the data regarding the relative demands and the replacement costs of the residential
end use fixtures, any retrofit demand management program that targets residential
customers should be in the following order of priority;
!
Shower roses
!
Garden watering systems
!
Clothes washing machines
!
Tap aerators, and
!
Toilets.
A preliminary analysis has been carried out that indicates that an active retrofit targeting the
replacement of shower heads with AAA rated shower heads would achieve an annual water
saving of 0.69 ML/d on its own. The cost if an active retrofit program has been estimated at
$100 000 per annum for four years. A trial program should be initially undertaken by Council
to gauge community acceptance and uptake levels for the retrofit scheme and to assess
specific customer groups and areas to target.
Financial incentive programs to encourage the purchase of more efficient washing
machines and garden watering systems may be considered after the shower head
replacement program has been run. Actual uptake levels from the showerhead retrofit
program could be used as an indicator for other proposed programs. The replacement of
11 L single flush toilets with 6 L/3 L dual flush toilets may be justified later within the period
covered by this study.
8.1.6
Non-residential Water Efficiency Program
From Figure 6-10 in section 6.4.1 it was shown that the metered consumption for the nonresidential sector accounts for 29.9% of the total shire water demand. Therefore reducing
water consumption in the non-residential sector can provide significant savings to overall
consumption. The best method of reducing the water consumption of non-residential
customers is by undertaking water audits, which are similar to those discussed in section
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Eurobodalla Integrated Water Cycle Management Strategy
8.1.4 for the residential sector. These audits may be conducted as a free service by Council
at a nominal cost and provide advice to the organisation on how to best conserve water and
hence reduce their water bills. The customers targeted by such a scheme could be
identified through the volume of water used from water bills or by their particular industry.
Program Based on Industry Type
Conducting water audits on an industry-by-industry basis allows programs to be initiated
that have similar salient features for different companies. By analysing the metered
consumption records it is possible to determine which industries have the highest individual
water use. The industries that contribute the greatest to water consumption in Eurobodalla
Shire include hospitality such as motels and clubs, hospitals, caravan parks, retirement
homes grouped by category type. The industries that contain the 35 highest water users in
the shire are shown diagrammatically in Figure 8-2 below.
10.9
11.8
18.2
101.7
27.3
29.3
62.7
Caravan Parks (10)
Houses (5)
Clubs (9)
Business (3)
Retirement Homes (2)
Motels (3)
Community Centre (1)
Hospitals (2)
56.4
Figure 8-2 Major Water Users by Customer Category (ML)
From Figure 8-2 it can be seen that caravan parks and motels are the largest nonresidential contributors on an industry basis to water demand. Therefore these would be
specific customer categories that would yield significant water savings from water audits
and therefore be high on the list of industries for water audits to target.. Interestingly,
residential dwellings also appear among the highest water users.
Council water use should not be exempt from the water audit process. Many of ESC
operations could potentially benefit from more water-efficient practices, such as irrigation of
council gardens and parks, public toilets and beach showers. These demands may be
unmetered and as such are easy to overlook in a demand management strategy.
8.1.7
Unaccounted for Water Assessment and Loss Reduction
It is important for ESC to accurately understand the current level of unaccounted for water
(UFW). Unaccounted-for water is usually in the range of 7–25% of bulk water supply and in
general this figure is related to the age of the distribution system and distribution pressure.
Anecdotal evidence suggests that water utilities tend to have a base UFW level of about 7–
8% for fire fighting, mains flushing and other utility activities. This figure also covers
breakages, overflows and difficult to trace illegal connections. Therefore an UFW level of 7–
8% is difficult to improve upon. However ESC’s UFW level of around 15% offers scope for
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Eurobodalla Integrated Water Cycle Management Strategy
improvement, with potentially substantial financial gains to Council available through
reducing the system leakage.
Council’s annual bulk production and metered consumption figures and the resulting
unaccounted-for water level from 1995 to 2001 are given in Table 8-1 below.
Table 8-1 Annual Unaccounted-for Water Figures From 1995 to 2001
Year
Production
(ML/a)
Consumption
(ML/a)
Unaccountedfor Water (ML/a)
Unaccountedfor Water (%)
1995
4 294
3 257
1 037
24.1%
1996
4 201
3 378
823
19.6%
1997
4 890
4 010
880
18.0%
1998
4 000
3 546
454
11.4%
1999
4 755
3 996
758
15.9%
2000
5 032
4 181
851
16.9%
2001
4 694
4 536
158
3.4%
It can be seen from the above table that the level of UFW has generally been between 10
and 20% of bulk production. The 1995 figure was higher than this range and the value for
2001 was 3.4%, which would reflect metering inconsistencies rather than real data. An
average figure of 16.4% has been assumed for this study (DLWC Eurobodalla Shire
Integrated Water Cycle Plan Supplementary Demand Report, 2002). Comparison of the
bulk production, metered consumption and UFW figures are shown graphically in Figure
8-3 below.
6,000
5,000
Annual Demand (ML/a)
4,000
Annual Consumption
Annual Production
Unaccounted for W ater
3,000
2,000
1,000
0
1995
1996
1997
1998
1999
2000
2001
Year
Figure 8-3 Bulk Production, Metered Consumption and UFW Figures From 1995 to
2001
Experience with other NSW councils that have implemented various metering and loss
reduction measures, suggests that an unaccounted-for water figure of about 15% could be
reduced to 8-9% (DLWC Performance Comparisons, 2000/01). A two-stage approach is
71
Eurobodalla Integrated Water Cycle Management Strategy
recommended to achieve this, with the first stage determining the current level of
unaccounted-for water, which would include assessing the existing metering system and
initiating metering improvements wherever necessary. The second stage is the loss
reduction program, which involves implementing various techniques to reduce system
losses.
Unaccounted for Water Assessment Opportunity
The determination of the current levels of unaccounted-for water would be achieved
through assessing the existing system and installing additional bulk water metering where
necessary, specifically at key reservoirs and pipelines in the short term, with expansion to
all reservoirs in the long term. This critical assessment of ESC’s distribution system will
ensure the detection of any flows that are not currently measured. In addition known points
of water use should be metered, including overhead fillers and Council sites. A program to
regularly calibrate the existing bulk water meters should be commenced and any faulty
meters be either repaired or replaced. The calibration of existing bulk water meters can be
carried out in conjunction with reservoir draw-down tests. An assessment of customer water
meters that have been in service for over 10 years would yield a number of low or zero
reading meters. Replacing faulty customer meters would provide more accurate
consumption records and increased revenue for Council.
Loss Reduction Opportunity
Once the existing system flows are determined and all bulk water meters are reading
accurately, preliminary water balances can be used to prioritise the areas for loss reduction
programs. These priorities can be refined until the target level of unaccounted-for water is
met. Water balances and minimum nightly flow tests can be undertaken at a reducing scale
to narrow the leakage search area. At the individual pipeline scale, physical detection
equipment such as spikes and transmitters or correlators that are operated by suitably
experienced personnel is required. The identification of areas of high pressure in the
distribution system and the installation of pressure reducing valves will help to reduce the
overall system losses by reducing the incidence of burst mains and also the flows from any
ruptures.
Benefits and Costs
As part of the regional supply strategy, this opportunity has been costed at $100 000/a for
the first four years and $20 000/a thereafter and is estimated to save 910 kL/a.
8.1.8
Water Pricing Opportunity
A major instrument of demand management in the urban water sector has been price
reform. The key element of this reform has been the move away from a ‘rating’ structure
based on property value to a ‘pay for service’ system that involves charging for water based
on the volume of water consumed. ESC introduced a ‘user pays’ pricing structure in 1993.
This has resulted in a reduction in water consumption in the non-residential sectors.
ESC’s current water charges comprise:
72
!
Water access charge – a fixed charge that varies only according to meter size.
Most domestic customers have a standard 20 mm diameter meter and therefore
currently pay a uniform water access charge. Consumers with larger meters pay
higher access charges.
!
Water usage charges - these charges are applied to measured consumption at the
customer’s meter. Thus every drop if water that passes through the meter is
charged. The current charge is $0.65/kL.
Eurobodalla Integrated Water Cycle Management Strategy
ESC’s strong belief that water conservation can be promoted through appropriate pricing
has been put into practice with the progressive increase in water prices over a number of
years. Water pricing has increased by 5c/kL/a over the past five years. However, ESC also
recognises that it is desirable to have prices cost-reflective to ensure that those consumers
on low incomes and businesses (and associated employment opportunities) are not
disadvantaged. Current water prices are not sufficient to promote conservation practices by
affluent water customers, and also do not adequately reflect the externalities of water use
such as the cost to the shire for environmental degradation caused by volume extractions.
There are novel approaches to water pricing currently being trialled water authorities both in
Australia and overseas that may bring about reductions in water demand. Two tier water
usage charges can be introduced that have a lower charge below a certain limit and an
increased charge for higher users. The charges can be set so that low income earners are
not disadvantaged and that the more affluent customers have an incentive to use water
more efficiently.
Another pricing option available to Council may be to provide increased water usage
charges during periods of peak demands or periods of hot, dry weather. Eurobodalla Shire
has a large influx of holiday-makers during the summer period and these people may not be
as sensitive to the local water conservation issues as permanent residents. Therefore
introducing increased water prices during these periods could provide a strong message to
all water users that water demands need to be reduced.
Council will need to couple any price increase with an extensive educational campaign to
explain the reasons behind these decisions and the benefits to the community and to the
environment.
Water pricing is an important demand management tool. Under NSW Water Supply
Sewerage and Trade Waste Pricing Guidelines (DLWC), water usage charges should
provide users with the appropriate pricing signal. Under best-practice pricing principles, the
price should reflect the long run marginal cost (LRMC) of the water supply system.
Marginal cost calculations result in a usage charge/kL that reflects the cost of supply. The
current usage charge is 65c/kL which is significantly lower than the LRMC. This results in
inefficient use of water resources and leads to a number of cross-subsidies between water
users. It is estimated that a real increase in the usage charge to around $1.20/kL is
appropriate, with a significant decrease in the fixed access charge. The increased usage
charge will result in a reduction in demand of approximately 0.11ML/day.
Transition to the new pricing structure can be immediate, with the fixed charge being
reduced at the same time to maintain Council's revenue base at an appropriate level. To
minimise anxiety in the community, it should be explained that as both the usage charge
and fixed charge are being adjusted, average water bills will remain at current levels. It
should also be emphasised that low and moderate water users will benefit from the pricing
adjustment and that all users will benefit from the demand reduction effect of the change
through lower treatment and transfer and capital investment costs that will be passed onto
consumers through lower water bills.
8.1.9
Water Waste Ordinance Opportunity
Water waste ordinance can be viewed as a method of water conservation, however
because of limited community acceptance should only be introduced out of necessity.
Members of the community may consider restrictions as an imposition and take up an
emotive debate over their introduction. Water restrictions can adversely impact upon the
high proportion of retirees in the area who spend a large amount of their leisure time
gardening. Allegations may also be made by the community that inadequate management
of the water resources has lead to the need for water restrictions. Therefore it is important
that a rational, thorough and transparent decision-making process is followed and that the
conclusions reached are conveyed to the community.
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Eurobodalla Integrated Water Cycle Management Strategy
Even though water restrictions are generally viewed as an effective method of demand
management, there is evidence to suggest that in some circumstances they may initially,
result in increasing demand. Rather than instilling a conservation mentality in customer’s
minds, some water users may not have realised that water was in short supply but feel that
their present situation is too important to reduce consumption and instead increase their
water use. This is usually seen when restrictions have only recently been introduced and
the level is not very strict. Increased demand reduction will generally occur as the level of
restrictions is increased and the need to conserve water is conveyed to the community.
Also the ability of Council to enforce these restrictions through fines and penalties is
important to the community’s adherence to them.
The present community sentiment toward water restrictions is that they are an imposition
from Council and are only required during periods of severe drought. However, there is an
opportunity to use the introduction of water restrictions in a broader context within in a
demand management framework. Restricting garden watering to early morning and
evening is one water restriction strategy that could be applied permanently. This strategy
not only achieves positive outcomes in terms of water efficiency, but it is more beneficial for
general plant health and growth. One of the major challenges facing ESC through the
implementation of the water conservation strategy is to change customers’ current
behavioural patterns of water use. As community awareness of water conservation issues
increases through the implementation of a successful demand management program, a
greater acceptance toward these issues is likely to result. This may also result in a change
to the community’s current perception of water restrictions. Rather than only introduce
restrictions during periods of severe drought, they could be used to help raise awareness
and reduce peak seasonal summer demands by introducing mild restrictions every
summer. The political repercussions of any decision made with regard to water restrictions
would need to be determined by Council prior to their introduction.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 8-2 Triple Bottom Line Assessment for Regional Water Demand Opportunities
DCP Content
Target Groups
Labelling of water
appliances
Garden Watering
Residential Water
Audit
Non - Residential
Water Audit
Demonstration
House
Showerhead
Retrofit
Toilet Retrofit
Washing Machine
Rebate
UFW and Loss
Reduction
Water Pricing
Water waste
ordinance
Water Use Efficiency
WSUD
Water Conservation Education
Water Efficiency
Planning Controls
Efficient use of fresh water resource
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Minimises low flow water extractions
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Minimises greenhouse gas emissions
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Minimises pollutants being discharged to the aquatic environment
1
3
2
1
1
2
0
0
0
1
1
1
1
0
0
Minimises urban stormwater volumes
0
3
3
0
0
0
0
0
1
0
0
0
0
0
0
Ensure sustainable practices
3
3
3
2
3
2
2
2
2
3
3
3
3
2
2
Environmental Sum
13
18
17
12
13
13
11
11
12
13
13
13
13
11
11
Environmental Rank
3
1
2
10
3
3
12
12
10
3
3
3
3
12
12
Improves security of town water supply
3
3
3
2
3
3
2
2
1
3
3
2
3
3
2
Improves the quality of drinking water
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Improves urban water service levels
2
2
2
1
1
1
1
1
1
2
2
2
3
2
2
Increases public awareness of urban water issues
2
2
2
2
2
3
2
2
2
2
2
2
1
3
3
Minimises non-compliance to policy and legislation
3
3
3
1
2
1
1
1
1
1
1
1
3
3
2
Protects public health
0
2
2
2
0
0
0
0
0
0
0
0
1
0
0
Social Sum
10
12
12
8
8
8
6
6
5
8
8
7
11
11
9
Social Rank
5
1
1
7
7
7
13
13
15
7
7
12
3
3
6
Benefit / Cost ratio (Council)
-
-
-
-
-
16
1.0
2.0
-
4.8
1.4
0.6
14
119
-
Financial Rank
-
-
-
-
2
7
5
-
4
6
8
3
1
TBL Score
-
-
-
-
-
12
32
30
-
14
16
22
9
16
-
TBL Rank
-
-
-
-
-
2
7
6
-
3
4
5
1
4
-
ENVIRONMENTAL
SOCIAL
FINANCIAL
Note: There is a lack of data for the water savings achievable with elements with a – in the Benefit cost ratio row . All planning options have been carried forward to the comprehensive demand management program.
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Eurobodalla Integrated Water Cycle Management Strategy
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Eurobodalla Integrated Water Cycle Management Strategy
8.1.10 Comprehensive demand management program
The opportunities for managing the regional water demand have been assessed on a TBL
basis. The opportunities which give the best outcomes on a triple bottom line basis have
been bundled together to form the comprehensive demand management program. The
elements of this program are:
!
Planing control by means of a DCP covering water sensitive urban design and
water efficiency for all new developments and extensions
!
Best practice water pricing
!
Unaccounted for water assessment and loss reduction program
!
An education program explaining the labelling of water efficient devices
!
An active showerhead retrofit
!
A water conservation education program targeting outdoor and non-residential
water use
The potential water saving of the comprehensive demand management program,
compared to the baseline case is shown in Figure 8-1.
8000
7000
Demand ML/a
6000
5000
Baseline
4000
Demand Management
3000
2000
1000
0
2002
2007
2012
2017
2022
2027
2032
Year
Figure 8-4 Potential Water Savings Through a Comprehensive Demand Management
Program
This comprehensive demand management program should be reassessed when the IWCM
strategy is reviewed in 5 years time.
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Eurobodalla Integrated Water Cycle Management Strategy
8.2
8.2.1
Opportunities for Developing the Local Supply Sources
Roof Water Harvesting
In high rainfall areas, it is possible to harvest considerable amounts of roofwater using
rainwater tanks. Recovery of roof water is not only a function of rainfall and tank size and
roof size, but also a function of water use. The use of rainwater tanks as a supply source
and water conservation measure in highly developed urban areas has increased in recent
years due to varied water applications and improved installations and technology.
In this study the roofwater harvesting using rainwater tanks was modelled as a
supplementary source of supply for the mains water. That is, when available, the harvested
roof water is used first, with mains water meeting the residual demand.
The rainwater tanks installation scenarios analysed included:
!
All new homes (permanent and holiday)
!
All new homes plus 20% of existing homes
!
All new homes plus 40% of existing homes.
For each of the above scenarios the harvested roof water was used for the following uses:
!
Garden watering only
!
Garden watering plus toilet flushing
!
Garden watering, toilet flushing and washing machines.
Modelling was conducted on an individual allotment basis and as part of the regional
scheme. The modelling assumptions, input parameters and the modelling process and
outputs, are discussed in detail in the ‘Yield Study Report’ (see appendix G) and the
Rainwater Tank appendix (appendix Z)
Table 8-4 below presents the percentage of the annual regional demand that can be
supplied by the harvested roof water for the various rainwater tanks installation and
nominated end use scenarios.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 8-3 Percentage of Total Regional Demand That Can Be Supplied Through
Rainwater Tanks (With No Other Demand Measures)
5 kL
Tank
10 kL
Tank
15 kL
Tank
20 kL
Tank
Garden Watering
3%
3%
4%
4%
New houses only
Garden and Toilet Use
4%
5%
5%
5%
(7 430 dwellings)
Garden, Toilet and
Washing Machines Use
5%
6%
7%
7%
New houses and
20% of existing
houses
Garden Watering
4%
5%
5%
5%
Garden and Toilet Use
5%
6%
7%
7%
Garden, Toilet and
Washing Machines Use
6%
8%
9%
10%
Garden Watering
5%
6%
6%
7%
Garden and Toilet Use
6%
8%
9%
9%
Garden, Toilet and
Washing Machines Use
8%
10%
12%
13%
Rainwater Use
(10 120 dwellings)
New houses and
40% of existing
houses
(12 810 dwellings)
Rebates
Council can consider passing on their capital and operational cost saving to landowners
who install rainwater tanks as a rebate (Table 8-4). These calculations, taking into account
the saving to Council in capital and operational costs, can be found in Appendix Z.
Table 8-4 Proposed Rebates For Rainwater Tank Installation
5 kL
10 kL
20 kL+
Garden use only
$470
$640
$735
Garden use plus toilet and/or washing machines
$510
$680
$780
Rainwater Tanks In All New Developments Opportunity
In this opportunity, 10 kL rainwater tanks could be mandated for all new developments, for
garden watering, toilet and washing machine use. This has the potential to reduced the
demands of the system by 425 ML/a or 6% of the regional water demands. Rebates could
be offered either on installation or through developer contributions.
Rainwater Tanks In All New Developments And 20% Of Existing Developments
Opportunity
In this opportunity, 10 kL rainwater tanks could be mandated for all new developments, for
garden watering, toilet and washing machines use. A rebate could also be offered for the
installation of rainwater tanks for garden watering into existing developments. An uptake of
20% may be achieved through the requirements to retrofit extensions to existing houses
with rainwater tanks. For existing houses rebates could be offered to offset the owner’s
cost. The opportunity has the potential to reduce the system demands by 510 ML/a or 7% of
total regional demands.
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Eurobodalla Integrated Water Cycle Management Strategy
Rainwater Tanks In All New Developments And 40% Of Existing Developments
Opportunity
In this opportunity, 10 kL rainwater tanks could be mandated for all new developments, for
garden watering, toilet and washing machines use. A rebate could also be offered for the
installation of rainwater tanks for garden watering into existing developments. In trying to
reach an uptake of 40% of existing houses an active promotion program is required. This
opportunity has the potential to reduce regional water demands by 600 ML/a or 9% in an
average year.
Community Costs of Rainwater Tanks
The cost for a householder to install a tank – taking into account the rebate offered by
council is shown in Table 8-5
Table 8-5 Single Household Cost to Rainwater Tank With Council Rebate
5 kL
10 kL
20 kL
Garden
$1 730
$1 860
$2 765
Garden + internal use
$1 620
$1 580
$2 385
Note: Further details on installation costs can be found in appendix Z
The yearly community costs to install rainwater tanks in
!
all new houses
!
all new houses and 20% of existing houses
!
all new houses and 40% of existing houses
within a 30 year period are shown in Table 8-6. The capital outlay costs do not include any
ongoing Council costs for management of rainwater tanks or householder costs for
operation, maintenance and renewal of tanks and pressure pumps.
Table 8-6 Total Yearly Community Costs for Rainwater Tanks Installation (including
rebate)
Use
5 kL
10 kL
20 kL
Garden
$428 579
$460 784
$684 983
Garden + internal use
$401 328
$391 419
$590 844
Garden
$583 644
$627 502
$932 819
Garden + internal use
$546 534
$533 039
$804 620
Garden
$738 710
$794 220
$1 180 655
Garden + internal use
$691 740
$674 660
$1 018 395
New Houses
New + 20% of
existing houses
New + 40% of
existing houses
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Eurobodalla Integrated Water Cycle Management Strategy
Table 8-7 Triple Bottom Line Assessment for the Regional Rainwater Tanks
Opportunities
10 kL RWTs in all
new
developments
10 kL RWTs in all
new
developments
plus 20%
existing houses
10 kL RWTs in all
new
developments
plus 40%
existing house
Ensures the efficient use of the
fresh water resource
1
2
3
Minimises water extractions and
protects low flows
1
2
3
Minimises greenhouse gas
emissions
2
2
2
Minimises pollutants being
discharged to the aquatic
environment
2
2
2
Minimises urban stormwater
volumes
1
2
3
Ensures sustainable practices
1
2
3
Environmental Sum
8
12
16
Environmental Rank
3
2
1
Improves security of town water
supply
3
3
3
Improves the quality of drinking
water
0
0
0
Improves urban water service levels
2
2
2
Increases public awareness of
urban water issues
2
3
3
Minimises non-compliance to
legislation
2
2
2
Protects public health
0
0
0
Social Sum
9
10
10
Social Rank
3
1
1
4.86
6.93
9.00
Financial Rank
1
2
3
TBL Sum
7
5
5
TBL Rank
3
1
1
ENVIRONMENTAL
SOCIAL
FINANCIAL (Community Costs)
NPV ($m over 30 years)
Technically Council will not incur any costs with the implementation of the above rainwater
tank opportunities. The cost of employing these options would be incurred by the
landowner, who would then be eligible for a rebate. This rebate would reflect the capital and
operating savings to Council as a result of the reduced impacts on the water supply system.
The financial costs given in the table reflect the costs that will be experienced by the
community with the implementation of each of the rainwater opportunities. According to the
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Eurobodalla Integrated Water Cycle Management Strategy
above TBL assessment, mandating rainwater tanks in all new developments and in 20%
and 40% of existing houses rank as equally suitable options in terms of environmental,
social and financial criteria. Whilst opportunity 3 achieves the best environmental outcomes,
it is the most expensive option in terms of community costs.
It is important to note that rainwater tanks are a relatively new concept to many people living
in areas supplied with reclaimed water and it is therefore difficult to predict their uptake by
the community. Whilst Council should aim to retrofit rainwater tanks in 40% of existing
houses, this in reality may be difficult to achieve.
Council has the opportunity to incorporate provisions into its DCP that make any
development application for house extensions or alterations exceeding a certain amount
(say $100 000) be subject to the mandatory installation of a rainwater tank. Through taking
this approach it may be possible to achieve a goal of a 20% retrofit of rainwater tanks in
existing houses.
Having taken into account the various issues surrounding rainwater tanks, mandating
rainwater tanks in all new developments plus 20% of existing houses has been carried
through to the regional supply options.
8.2.2
Stormwater Harvesting
There is the potential to incorporate stormwater harvesting into local stormwater detention
and water quality control features. Preliminary calculations for Eurobodalla Shire rainfall
conditions indicate that a 100 ha catchment draining to a 5 ML water quality control pond
would yield up to 50 ML of water for open space irrigation in a year of average rainfall and
about 30 ML in a dry year.
The potential for stormwater harvesting in Eurobodalla Shire will vary considerably
depending on local topography and other factors. The cost of stormwater control ponds is
site specific, so the unit cost of water from stormwater harvesting systems can vary
considerably. It is likely to be more cost effective to utilise harvested stormwater in water
quality control ponds for public landscape needs rather than to supply residential
consumers. Public open space within Eurobodalla was assessed for its suitability for
stormwater harvesting. This is discussed further in the local water management plans and
in section 6 of appendix W). Incorporating stormwater harvesting in new urban subdivisions
in most cases would be cheaper option. This should be covered by the development control
plan discussed in section 8.1.3.
Stormwater harvesting needs to be balanced with environmental considerations. While it is
beneficial to harvest excess stormwater runoff, harvesting all of the stormwater during dry
periods may impact adversely on local streams and waterways. In high rainfall locations
such as Eurobodalla, with limited irrigation opportunities, it can be argued that it is more
beneficial environmentally to maximise use of reclaimed water first before implementing
stormwater harvesting systems.
8.2.3
Residential Greywater Reuse
Specific greywater reuse is discussed further in the local water management opportunities.
The provision of sewerage systems in currently unsewered areas allows the utilisation of
suitable treatment systems for local greywater reuse. As there are currently no approved
greywater treatment devices (besides those approved for on-site treatment of wastewater)
no recommendations have been made for greywater systems in currently sewered areas. In
areas Council is proposing to provide a reticulated sewerage system, there is the
opportunity for residents to retain their septic tanks and on-site treatment devices for
irrigation purposes.
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Eurobodalla Integrated Water Cycle Management Strategy
8.2.4
Benefits of Utilising Local Water Sources
The advantages of harvesting water in the local area are:
8.3
8.3.1
!
Increased yields during droughts
!
The economic benefits of freeing up peak day capacity in the Eurobodalla system
to serve other users
!
The garden water benefits to householders, particularly during droughts
!
The environmental benefits of reduced freshwater diversions above the tidal limit
!
The environmental benefits of reduced reclaimed water and stormwater discharges
to the estuary or the ocean
!
Reduced stormwater infrastructure
Opportunities for Developing the Regional Supply Sources
General Overview
The introduction of environmental flow regime and water-sharing rules under the Water
Management Act limits the secure yield of the existing regional water supply system.
Among other factors the size and timing of the source infrastructure expansion also
depends on the environmental flow regime and water-sharing rule that will be added to any
new licence condition.
Since it is widely accepted that the ecosystems and the conservation values can become
stressed during low stream flows, in the future water extraction for the regional scheme
would predominantly be during high stream flows. This necessitates filtration of the supply
sources in the short term to protect public health and targeted remedial works, and
protection of the riparian zones to improve the stream water quality in the long term. Thus
all supply opportunities considered include filtration of the surface water supplies. The
recommended filtration processes include the mechanical and chemical-based dissolved air
flotation sand filtration process and the physical and possibly chemical-free membrane
filtration process.
In the long term, the base case environmental flow regime and total flow protection supply
access conditions could be accommodated either by providing new sources of supply (e.g.
new off-river storage or desalination) and/or by utilising the existing sources more
efficiently. Supply opportunities have been developed based on both approaches and the
risks and benefits of each opportunity are also outlined. Since all opportunities have social
and environmental impacts (e.g. other water users, ecosystems, conservation values, etc.),
any decision to expand existing supply infrastructure and/or provide additional sources
would be subject to extensive environmental impact assessment processes, including
community consultation and detailed engineering studies.
Since the timing of the supply source expansions depends on a number of factors such as
extraction regime, restriction policy and demand growth, the order in which the
infrastructure is expanded is crucial to the security of supply. The preferred order is to
improve the existing system reliability and then expand the extraction/transfer capacities
along with water filtration, followed by the expansion of drought storage facility. The first two
measures are referred to as immediate and short term measures, and the
expansion/provision of the drought storage facility is considered as the long term option.
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Eurobodalla Integrated Water Cycle Management Strategy
8.3.2
Immediate Measures
The existing supply scheme has some inherent deficiencies. These deficiencies could be
easily overcome with appropriate immediate measures. Implementing the immediate
measures will greatly assist Council to recover from the current drought and improve the
system reliability. The deficiencies and the recommended immediate measures are
discussed below.
One of the problems Council regularly experiences after drought or after periods of being
solely reliant on the dam is the long period it takes to fill the Deep Creek Dam. Additionally,
Council is also reliant on Deep Creek Dam water to meet peak demands in the Batemans
Bay area, the reason for this being:
!
the small gravity transfer rate between Moruya Main Reservoir and the dam
!
the design and operational problems associated with the Malua Bay booster
pumping station, and
!
the inability of Moruya River pumps to run in parallel.
Hydraulic analysis (see appendix I) indicates that the transfer rate from Moruya main to
Batemans Bay could be increased by either relocating the existing Malua Bay booster
pumps and electrics to the disused Mossy Point booster pumping station, or by installing a
smaller pump within the existing Malua Bay booster pumping station.
Analysis shows that relocating the existing pumps and the electrical components is a more
viable option than installing a smaller pump. This is due to the better dual functionality (i.e.
relative ability to transfer more water in both directions by the same pump) achievable at
Mossy Point compared to Malua Bay. Upgrading the power supply to the Moruya River
pumps will enable parallel operation of the pumps and the ability to harvest more water.
The second issue currently faced by Council is the inability of the Tuross River system to
meet peak demands due to inherent river extraction problems, the flow mismatch between
the low and high head pumps, and the inadequate power supply to run pumps in parallel.
Council is currently implementing measures to overcome the river extraction problems.
Council should also consider eliminating the flow mismatch between the low and high head
pumps by either installing variable speed drives on existing pumps or by installing newer
pumps. The power supply upgrade to the Tuross River pump station should also be
expedited.
The third issue is the inability of the existing telemetry and the control elements on the
reservoirs and valves to operate in a narrow and more efficient range. Newer technologies
are now available to improve this situation. Therefore Council should consider undertaking
a review of the current operating concept with a view to improving efficiency and capacity.
The fourth issue is maintaining an appropriate chlorine residual throught the system. To
addess this requires the provision of rechlorination facilities at strategic locations.
8.3.3
Short term Measures
Short term measures include both the ability to harvest higher river flows and the ability to
transfer and store water quickly in Deep Creek Dam. This could be achieved by
implementing the following works.
!
84
A dedicated pipeline between Moruya River intake and Deep Creek Dam. It is
proposed to locate the pipeline along the existing high voltage transmission
easement. This will minimise environmental and social impacts during construction
and contain development within existing disturbed area. Economic analysis
Eurobodalla Integrated Water Cycle Management Strategy
indicates that the optimum pipe diameter is 600 mm (see appendix J for additional
information).
8.3.4
!
Filtration of the water supplied to the consumers. This could be achieved with two
filtration plants utilising either the dissolved air flotation with sand/coal filtration or
membrane filtration process (see appendix H for a discussion of water treatment
processes). One plant will be located near Denhams Beach reservoir (or near
Moruya main reservoir, See Appendix I) to serve the population between Long
Beach and Tuross Head under normal periods and up to Central Tilba during
drought periods. This plant will filter water sourced from the Buckenboura and
Moruya Rivers as well as that stored in Deep Creek Dam. The other plant will be
located near the Tuross River Intake and will filter water sourced from the Tuross
River. It will predominantly serve the southern population from Bodalla to Central
Tilba. The capacity of both treatment plants is dependent on the extent of bundling
with the other sources and measures.
!
Active water conservation program to bring about behavioural and cultural change
in the use of water among the consumers. This program would be an extension of
Council’s current program and should include school, community and interest group
education through a number of communication channels.
Long term Regional Supply Opportunities
The long term regional supply opportunities are related to securing a water source or
storage to meet drought needs. This could be provided by enlarging the existing Deep
Creek Dam, a new off-river storage and/or by the desalinisation of seawater. A review was
undertaken to evaluate the feasibility and cost of enlarging Deep Creek Dam and to identify
and cost new alternative dam sites in the central and southern area of the shire. The results
of this review are included as appendix K. In summary the review identified two preferred
sites in the southern area (Stoney Creek No. 2 and Tuross No. 2) and one preferred site
(Barretts Creek) in the central area.
Table 8-8 provides the scheme cost of the regional water supply using the regional supply
opportunities. These scheme costs are based on meeting the base case environmental flow
extraction regime of 95/30. Scheme costs to meet a more conservative than the base case
environmental flow extraction regime is provided at the end of this Section for comparison
purposes (80/30 extraction).
Table 8-8 Scheme Estimates of Long Term Regional Supply Opportunities
Opportunity
$/ML of Yield
1
1
Raise Deep Creek Dam
7.7-9.5
2
New southern off-river storage
8.7
3
New central off-river storage
12.6
4
Desalination as new supply source
8.1
The cost of all opportunities includes common immediate and short term measures
Note 1 Costs vary depending on the location of the water filtration plant the northern area of the shire
Appendix L on regional water supply costs and present value analysis provides the detailed
costing information.
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Eurobodalla Integrated Water Cycle Management Strategy
Opportunity 1: Raise Deep Creek Dam
In this opportunity drought storage is increased by raising Deep Creek Dam. The
opportunity limits the environmental footprint of off-river storage mainly to previously
disturbed areas and maximises use of the existing assets. The disadvantages of this option
are that the whole scheme’s drought security is confined to one storage and there is a limit
on Deep Creek Dam’s capacity for expansion. Thus in the unlikely event of any major water
quality and/or structural problem with the dam, the ability of the headworks to meet
demands would be reduced. This opportunity would further stress the already stressed
Moruya River by increasing extraction.
Opportunity 2: New Southern Off-River Storage
This opportunity involves a Southern off-river storage to be filled by high flow band water
from the Tuross River. This option spreads drought security over two storages, resulting in
a reduced risk from water quality and/or structural problems. This opportunity also improves
operational flexibility of the scheme whereby water could be selectively pumped from three
river sources and moved in both directions to the demand centres. It also reduces the
impact that a trunk main break between Moruya and Narooma would have on supply to the
south of the shire.
Further this opportunity helps to minimise urban extraction stress of the Moruya River by
sharing extraction with the Tuross River. In the long term this opportunity would assist in
meeting peak day demand in both Southern and Central areas of the shire without major
distribution pipeline upgrades. It will also enable Council to meet at minimal cost any future
conservative river flow access regime.
Analysis indicates that it is possible to locate the storage high in a catchment to reduce the
environmental impacts of a storage on the downstream catchment. Further, it is also
possible to select a site that can be raised in the future to increase storage capacity.
Opportunity 3: New Central Off-River Storage
This opportunity is based on a central off-river storage to be filled from the high flow bands
of the Moruya River. Extraction of water from the Tuross River would cease, protecting this
river from urban extraction. However, this opportunity would result in increasing urban
expansion stress on Moruya River and risk to regional water supply through greater reliance
on a single source.
Unlike opportunity 1 the drought security risk is spread over two storages resulting in
reduced supply security risks from water quality and dam structural problems. Although, in
this opportunity, the regional scheme could be supplied from a single water filtration plant,
in the long term the coastal distribution pipelines may require significant upgrading to meet
peak day demands.
Unlike opportunity 2, in this opportunity any breakage in the trunk main to Narooma could
result in prolonged supply interruptions. Any future conservative river extraction regimes
would result in significant headworks costs.
Analysis indicates that it is possible to locate the storage high in a catchment to reduce the
environmental impact of storage on the catchment. It is also possible to select a site that
can be raised in the future to increase storage capacity. However suitable locations for such
a storage will incur high pumping costs.
Opportunity 4: Desalination as New Supply Source
This opportunity is based on either a 5 ML/d reverse osmosis unit driven by energy from the
grid or a 5 ML/d composite MED-RO system driven by about 35 solar dishes. Additional
information on desalination processes, unit costs and factors influencing site selection are
provided in appendix M. There are two ways in which desalination could be used in
86
Eurobodalla Integrated Water Cycle Management Strategy
Eurobodalla. The two options are either as a long term regular water source or as a drought
contingency option.
A desalination plant provides a drought proof supply source and the novel technology has
potential to attract tourist visitation. It reduces the dependence on surface waters, however
it produces a brine stream that must be disposed of. The plant needs to be located on the
coast, which may reduce the visual amenity of the area and may be located on a potential
development area. Desalination plants can be expensive to operate due to their high energy
use, which can result in greenhouse gas emission. Like opportunities 2 and 3, it spreads
risks associated with water supply including reducing reliance on extended delivery mains.
Social and Environmental Aspects of the Long term Supply Opportunities
The above opportunities, whilst being developed based on a 50-year planning horizon, will
be implemented in stages. The TBL assessment table below provides the comparative
environmental, social and economic benefit of each strategy option.
Table 8-9 Social and Environmental Aspects – Long term Supply Opportunities
Opportunities
Social
Maximises use of existing assets
Opportunity 1
Raise Deep Creek Dam
Opportunity 2 New
Southern Off-River Storage
Environmental
Proposal footprint
predominantly confined to
previously disturbed areas
Drought security confined to one storage
Limited construction work
Further increases extraction
from Moruya River, although in
high flows
Spreads drought security (and water quality)
risk between two storages and two supply
sources
River harvesting shared
between two sources
Acceptance (and social impact) of proposal to
build new storage
Creates a new footprint and
associated environmental
impact
Reduced reliance on extended delivery mains
Spreads drought security risk between two
storages but extraction based on one supply
source
Opportunity 3 New Central
Off-River Storage
More water available to environment and
irrigators on Tuross River
Acceptance (and social impact) of proposal to
build new storage
Increased reliance on Moruya
River and higher environmental
impacts to river environment
Tuross River environment
protected
High pumping costs
Plant located on possible development area
Opportunity 4 Desalination
Technology has potential to attract tourist
visitation
High energy use, resulting in
greenhouse gas emission
Public acceptance of this option for potable
uses (unknown)
Potential issues with brine
disposal
Enhances drought-proofing of the scheme
Reduced dependence on
surface waters
Reduced reliance on extended delivery mains
Expensive to operate
The Project Team ranked the above opportunities. The triple bottom line assessment
represented in Table 8-10 provides the relative ranking of each strategy option.
87
Eurobodalla Integrated Water Cycle Management Strategy
Deep Creek
Dam
Southern
Dam
Central Dam
Desalination
Table 8-10 Triple Bottom Line Assessment of Regional Water Supply Opportunities
1
2
3
4
Ensures efficient use of the fresh water resource
1
1
1
2
Minimises water extractions and protects low flows
1
1
1
3
Minimises greenhouse gas emissions
1
1
0
0
Minimises pollutants being discharged to the
aquatic environment
2
2
3
0
Minimises urban stormwater volumes
0
0
0
0
Ensures sustainable practices
1
1
0
0
Environmental Sum
6
6
5
5
Environmental Rank
1
1
4
4
Improves security of town water supply
2
3
2
3
Improves the quality of drinking water
3
3
3
2
Improves urban water service levels
2
3
2
3
Increases public awareness of urban water issues
1
1
1
1
Minimises non-compliance to legislation
2
3
2
2
Protects public health
2
3
3
3
Social Sum
12
16
13
14
Social Rank
6
1
3
2
7.7-9.5
8.7
12.6
8.1
Financial Rank
1
3
4
2
TBL Sum
8
5
11
8
TBL Rank
2
1
4
2
ENVIRONMENTAL
SOCIAL
FINANCIAL
$/ML
Note: Ranking are done on $/ML to asses to cost of each supply opportunity to meet the needs of the regional
scheme. The quality of water required by the scheme is determined in section 10
The ranking in the balanced score card suggests that if in the future the existing drought
storage needs to be enhanced then the preferred strategy would be to develop a new offriver storage facility in the south of the shire. This off-river storage would be filled by
harvesting high flow bands from Tuross River (i.e. Opportunity 2).
Sensitivity of Preferred Opportunity to Demand-Supply Variations
The system modelling was carried out on demand projections based in current and future
average annual demands. The secure yield and thus the opportunities are sensitive to the
following aspects of system modelling.
88
!
Increases in water needs during drought periods relative to average annual
demands
!
The 20% demand reduction during drought restrictions
Eurobodalla Integrated Water Cycle Management Strategy
!
Environmental flow protection regime
!
Climatic variation including catchment land use
!
Demand reduction program suggested in this report
These individual impacts are discussed below for Opportunity 2.
Increased Water Needs
Modelling is based on the average demand (not the drought demands). It is important to
note that unrestricted demands are usually higher during drought periods due to higher
evaporation and lower rainfall resulting in greater garden water needs. Demand increase
may be in the range of 10% to 12%. Early restrictions may reduce this impact.
Sensitivity to 20% Demand Reduction During Drought Restrictions
The modelling of the water supply system assumes that a 20% reduction in demand can be
achieved with the imposition of restrictions. Experience from other NSW coastal country
towns has shown that the natural propagation of water efficiency measures and the
voluntary conservative use of water have in many instances reduced the ability of
restrictions to reduce the demands during droughts. Increased water needs during droughts
may exacerbate the effect. The sensitivity analysis on the preferred opportunity with no
demand reduction during a drought shows that the secure yield would reduce by about
14%. To maintain the same secure yield the new drought storage capacity in the south
would need to be about 1 400 ML instead of 100 ML. Alternatively, the construction of the
new southern drought storage would need to be brought forward by about 5–10 years.
Sensitivity to Environmental Flow Protection Regime
During the agency meeting (October 2002 at Batemans Bay), it was suggested that future
water-sharing plans might require a higher low flow protection regime. Whilst such changes
are not expected until at least 2020, the analysis shows that the impact of moving from the
base case 95/30 low flow protection rule to a higher 80/30 low flow protection rule is
significant.
The modelling results show that the existing headworks with higher low flow protection are
inadequate to supply the current demands and therefore larger off-river storage is required
by 2020. As an example, for a yield of 6 980 ML, a 2 800 ML off-creek storage is required
for 80/30 extraction compared to 200 ML with 95/30.
The main social benefit of moving to a higher low flow protection includes the possible
higher economic return from agricultural and oyster farmers resulting in an overall improved
sustainability of these industries. The environmental benefits include the increased
sustainability of rivers and estuaries, and those species that rely on them.
Sensitivity to Climate and Land Use Changes
Evaporation increases due to global warming may lead to increased urban water demands
for outdoor uses. Analysis indicates that this increase could be as high as 10% during
drought periods. It is very likely that this increase in future demand could be offset by the
demand reductions achieved through natural propagation of water efficiency appliances and
fittings, education campaigns and reduced outdoor water use.
Global warming could also have an impact on the streamflows. Climate modelling predicts
that the annual runoffs could vary significantly in the next 50 years. The variation could
result in an increase or decrease in streamflows.
Catchment landuse practices also have an impact on the streamflows. For instance after
the 1939 bushfires in the Melbourne water supply catchment, the streamflows initially
89
Eurobodalla Integrated Water Cycle Management Strategy
increased and then significantly reduced for a prolonged period as a result of the higher
water usage by the forest during their regrowth phase.
Sensitivity analysis with a 10% reduction in the historical streamflows shows little impact on
the secure yield. A 10% decrease in streamflows increases the drought storage
requirements by 200 ML (2032).
Sensitivity to Demand Reduction Programs
The demand reduction programs suggested in a previous Section of this report have the
potential to reduce the base demand by about 12% in the next 30 years.
This will defer the need for the new southern dam by about 15 years. Further it will also
deliver consumer savings in water and energy cost and lessens the environmental impact
of population increases on water resources.
Comparison of the Sensitivity Analysis
Table 8-11 below provides the economic implication of each demand and supply variable to
the preferred opportunity 2. Opportunity 2 is based on the future storage in the south of the
shire.
Table 8-11 Comparative Costs for Stand Alone Supply Demand Sensitivities
Stand Alone Sensitivity to Opportunity 2
Cost Estimates ($m)
Capital Cost
NPV @ 7%
Demand reduction during drought restrictions
82.0
66.8
Higher environmental flow protection
84.8
73.5
Climate and land use changes
55.8
64.9
Demand reduction programs
55.3
64.6
However it should be noted that the economic impact of two or more supply-demand
variations occurring together would be significantly different to that shown in the above
table. Detailed cost information is contained in Appendix L
8.4
Opportunities for Reclaimed Water Use
ESC aims to recycle and reuse reclaimed water to achieve environmental and social
benefits where it is economically viable and socially acceptable. The environmental and
social benefits include:
90
!
Conserving the water resources by reducing water extractions
!
Reducing the direct discharge of reclaimed water to waterways
!
Replacing where appropriate the use of town water with more reliable reclaimed
water
!
Enhancing the quality and sustainability of ground and surface waters
!
Supporting and enhancing the local agricultural industry.
Eurobodalla Integrated Water Cycle Management Strategy
8.4.1
Project Initiatives
In 1998 Council undertook a shire-wide reclaimed water and biosolids reuse study, which
canvassed both local and regional land-based reuse opportunities. In view of the high cost
associated with the regional schemes, Council has been focusing on some of the local
opportunities. Current reuse and recycling initiatives include:
!
Reuse at Batemans Bay and Moruya golf clubs
!
Reuse at Moruya sporting fields
!
Proposed reuse distribution main for the agricultural and industrial areas near
Moruya.
The project to reuse reclaimed water from a reed bed on Tuross golf course, whilst having
secured Government funds, was shelved due to community objections. The use of
reclaimed water from Bingie STP for irrigating Tuross Golf Course is still supported by the
community.
The current reuse projects use about 5% of the average dry weather reclaimed water
volumes produced in the shire. The additional initiatives proposed for the area would use an
additional 5% of the current dry weather shire flows.
8.4.2
Reclaimed Water Volumes
Reclaimed water is currently produced at the five sewage treatment plants owned and
operated by Council. Table 8-12 below shows the current and forecast future volumes
expected to be produced in the next 30 years from the five plants. Additional volumes may
become available if sewage from the currently unsewered villages were to be centrally
treated by Council to secondary standards.
Table 8-12 Reclaimed Water Volume Projections
Volume
Description
Average Daily (ML/d)
Current
Future
Annual (ML/a)
Current
Future
Batemans Bay and
Surrounds
4.0
5.0
1 900
2 300
Tomakin and Surrounds
1.0
1.5
450
700
Moruya and Surrounds
0.8
1.0
380
450
Tuross
0.7
0.8
330
380
Narooma and Surrounds
1.6
2.4
760
1 100
-
0.4
-
200
8.1
11.1
3 820
5 130
Other Villages
Shire Total
Table 8-12 shows that in the next 30 years the reclaimed water volume for the shire will
potentially increase by about 35%.
8.4.3
Reclaimed Water Use
It is important to recognise that the required reclaimed water quality differs for each
intended end use. Therefore, it is important to provide a quality product that is acceptable to
91
Eurobodalla Integrated Water Cycle Management Strategy
that end use. Whilst technology is available to produce reclaimed water of highest purity
devoid of any contaminants, for most end uses this level of treatment is not warranted. See
appendix D for the minimum acceptable quality for most end uses. In Eurobodalla the main
uses for reclaimed water are:
!
Urban open space
!
Industrial
!
Agriculture (broad acre and constructed environment)
!
Residential non-potable
!
Potable (direct and indirect)
!
Environmental
At the inter-agency meeting held in October 2002, the Department of Health asserted that it
would not support potable (direct and indirect) reclaimed water reuse.
Urban Open Space and Industrial
Reclaimed water is currently reused at Batemans Bay and Moruya golf courses. There may
be scope to extend recycled water systems to irrigate other urban open space areas
including:
!
Batemans Bay
Hanging Rock Gardens (16 ha)
!
Tuross
Golf course and Parks (28 ha)
!
Moruya
Racecourse (47 ha)
!
Narooma
Golf course (15 ha)
!
Tomakin
Captain Oldrey Park, The Oaks Ranch Country Golf Club,
Sports Club Park
It is estimated that utilising reclaimed water for these areas would result in the reuse of an
additional 5% of current total shire flow. Currently the abovementioned open space areas
do not use town water supplies, however utilising reclaimed water on these sites would
provide an aesthetic appeal to the area by keeping the grass green all year round including
during drought periods.
Residential Non-Potable
NSW has pioneered the development of water recycling for residential use in Australia. The
1993 NSW Guidelines for Urban and Residential Use of Reclaimed Water were the first of
its kind in Australia. The major residential reuse scheme in Newington Village at Sydney
Olympic Park was commissioned in April 2001. The major residential reuse system at
Rouse Hill in north-western Sydney has been up and running for 18 months. Another major
residential reuse scheme is under construction at Mawson Lakes in Adelaide.
An examination has been made of a possible residential reuse system for the Rosedale
development. The system would feature a service reservoir as a central storage, and a
reticulation system specifically constructed for the delivery of reclaimed water for garden
watering, toilet flushing and washing machines (cold water only). Recycled water for
household use must meet the NSW Guidelines for Urban and Residential Use of Reclaimed
Water developed by the NSW Recycled Water Co-ordination Committee. These guidelines
include limits for microbiological and physical criteria along with general guidelines for
nutrients and trace contaminants. Delivery from a water reclamation facility including
92
Eurobodalla Integrated Water Cycle Management Strategy
membrane filtration and disinfection at the Tomakin STP would be more cost effective than
sewer mining.
Considerable effort is being applied worldwide to the development of appropriate
technologies and management systems for on-site wastewater management systems.
There are a variety of new on-site and decentralised treatment systems coming on to the
market which provide potential to undertake water recycling on a household, neighbourhood
or subdivision scale at a similar or less overall cost than a fully reticulated water recycling
system from a centralised treatment system. A number of these systems have been
successfully implemented in the USA. Factors important for a successful system include a
careful evaluation of the site capability to ensure that there will not be adverse health and
environmental impacts, and the adoption of centralised management of decentralised
treatment and recycling systems.
The bulk supply of reclaimed water to large urban landscaping and industrial customers is
usually more cost effective than residential reuse. Due to the small number of large
commercial and industrial consumers in the Eurobodalla Shire, the potential for commercial
and industrial reuse is minimal.
It might be possible to justify the development of a dual reticulation reclaimed water system
for Rosedale and other new development areas when account is taken of:
!
The benefits of increased yield in droughts
!
The economic benefits of freeing up peak day capacity in the system to serve other
users
!
The garden water benefits to householders, particularly during droughts
!
The environmental benefits of reduced freshwater diversions above the tidal limit,
and
!
The environmental benefits of reduced reclaimed water discharges to the estuary
or the ocean.
Previous analysis indicates that the capital cost associated with a second reclaimed water
reticulation network is about $2 560/lot. This cost includes the plumbing costs. The annual
operating, maintenance, compliance and monitoring costs are about 10% of the capital
cost. Therefore to service 1 000 new lots would cost around $2.6m.
Agriculture – Cropping in Natural and Constructed Environment
Agricultural cropping in the natural environment refers to the conventional practice of broad
acre farming. There are many examples of ‘cropping in the natural environment’ agricultural
reuse schemes in Australia, however most of these are undertaken in areas with lower
rainfall. Examples include irrigation of sugar cane crops along the drier parts of the
Queensland coast, the major scheme to irrigate dairy pasture now under construction in the
northern Shoalhaven area near Nowra in NSW, and irrigation of horticultural crops at
Virginia in South Australia.
Agricultural cropping in a constructed environment includes nurseries and open and
covered hydroponic systems. Although there are currently no such enterprises within
Eurobodalla, Council could promote these types of enterprises given their high margins and
the water use of these types of enterprises. Additional information on these types of
enterprises is contained in appendix N2.
The shire-wide reclaimed water reuse review has identified the Moruya and Tuross River
flats as the two major dairy and agricultural regions in the shire. The Moruya region
comprises approximately 1 000 ha of dairy land and the agricultural and the Tuross region
contains about 1 500 ha.
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Eurobodalla Integrated Water Cycle Management Strategy
The high rainfall within the Eurobodalla Shire would restrict the reuse opportunities available
particularly for cropping in natural environment systems. The high rainfall and the highly
seasonal nature of the NSW south coast climate means that the reuse potential for
cropping under natural conditions is highest during the dry season in late spring and early
summer. Therefore it may be likely that there will be lengthy periods during the wet season
from December to April when little or no reuse is viable. Thus, practical reuse strategies
should aim to reuse a high percentage of dry weather flows, in combination with appropriate
alternative arrangements to treat all wet weather flows to a standard suitable for direct
discharge to the environment.
Two regional schemes could be developed based on opportunistic reuse (i.e. when there is
a demand). These scheme options are discussed below. However, it should be noted that
there are a number of significant constraints to agricultural reuse in the natural environment
such as:
!
Landforms and land slopes
!
High water tables on many areas of the floodplain
!
Shallow acid sulfate soils
!
Large environmental protection zones
!
The potential for elevated sodicity to cause deterioration in soil structure.
Northern Region Scheme
In the northern scheme, the dairy area around Moruya River could be supplied with
reclaimed water produced from the sewage treatment plants located north of Moruya. The
shire-wide reuse study proposed to use a dedicated main to transfer reclaimed water from
the Batemans Bay and Tomakin sewage treatment plants to this area. The shire-wide study
also considered a wet weather/peak demand balancing storage near Moruya to manage the
supply and demand peaks.
A review of the shire-wide reuse study within the integrated water management context
indicated that an alternative option to constructing a new main from Batemans Bay would
be to utilise the existing old 250 mm water supply main. This water main runs parallel to the
new 450 mm main and could be used for transporting the reclaimed water. The disused
Catalina 1 reservoir could then be used as the balancing storage if required. The hydraulic
analysis of the regional water supply indicates that the water supply demands could be met
through the existing 450 mm main and no augmentation to the 450 mm main would be
required if the northern water filtration plant was located near Denhams Beach Reservoir.
The schematic of this scheme concept is shown in Figure 8-5.
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Eurobodalla Integrated Water Cycle Management Strategy
Figure 8-5 Topographic Layout of Northern Regional Scheme
Southern Region Scheme
The southern scheme is based on irrigating the agricultural and dairy farms around the
Tuross River region. Similar to the shire-wide study, it is proposed to use a dedicated main
to transfer reclaimed water from both the Tuross Head and Narooma sewage treatment
plants. However, unlike in the shire-wide study, no wet weather/peak demand balancing
storage is proposed. Farmers would be required to provide their own operational storage,
which would be topped-up from the regional pipe main. The schematic of this scheme
concept is shown below.
95
Eurobodalla Integrated Water Cycle Management Strategy
Figure 8-6 Southern Regional Reuse Scheme
96
Eurobodalla Integrated Water Cycle Management Strategy
Environmental Reuse
Environmental reuse involves the discharge of highly treated reclaimed water back to the
river or aquifer system to improve the sustainability of the water resources. The reclaimed
water quality in most instances would be of a better quality than that of the receiving water.
In Eurobodalla, opportunities for environmental reuse include discharging upstream of
irrigators on the Duea/Moruya River and recharging coastal aquifers such as the Broulee
aquifer. The benefits of both the reuse options are discussed below.
Environmental Flows
Under the NSW Water Reforms, river flow objectives have been developed which give the
environment priority of water use during low flow periods with water only able to be diverted
for human use when minimum environmental needs have been satisfied. In most cases this
requires the construction of additional storage facilities to meet water needs during drought.
Under the Water Management Act, if there are users downstream of the discharge point
(including the environment), then the return of highly treated reclaimed water can be
credited against the extraction limit. Therefore if the environmental flow needs could be met
with reclaimed water, it may be possible to increase the yield of the water supply system
and make savings in water supply augmentation costs. The WM Act supports ‘in principle’
the sustainable use of treated reclaimed water as substitute for environmental flows. It is
understood that the relevant regulatory agencies are developing the rules under which
environmental flow credits would apply for reclaimed water.
There may be the potential to use reclaimed water from the northern regional agricultural
reuse scheme to meet the needs of water extractors. The reclaimed water used for
environmental flow substitution would need to be treated to a high standard to be
acceptable for this purpose. This reuse strategy has the potential to defer the need for
additional water storage in the regional water supply scheme. Environmental return flows
are most needed in dry periods, which tend to coincide with high irrigation demand periods.
It is likely that further studies would be required to demonstrate the environmental
acceptability of this opportunity.
Preliminary yield analysis indicates that every megalitre of reclaimed water substituted for
environmental flow in the Moruya River would provide about 1 ML of extra yield. For
example, 5 ML/d of highly treated reclaimed water with a one-to-three dilution would give an
annual yield of 1 000 ML/a. In assessing and sizing the major scheme components of this
opportunity, it has been assumed that reclaimed water will be available on demand from
Batemans Bay, Tomakin and Moruya. The reclaimed water that would be used as
environmental flow substitute upstream of the water extractors will be filtered in a
membrane plant and disinfected using UV. Performance monitoring results obtained from
reclaimed water plants using this treatment process train show that the reclaimed water
produced is free of pathogens and has water quality comparable to the NSW Guidelines for
Urban and Residential Use of Reclaimed Water (Ref. 2).
In a recent inter-agency meeting (October 2002, Batemans Bay) it was suggested that the
following activities should be undertaken to further establish the feasibility of this
opportunity.
!
A comprehensive risk analysis to demonstrate that the reclaimed water does not
pose any public health or environmental risks including to water users and the
dependent ecosystems.
!
A water balance analysis to demonstrate that the sustainability of the river is
maintained and protected, particularly at low flows.
!
A study to establish the minimum reclaimed water quality to maintain river
sustainability.
97
Eurobodalla Integrated Water Cycle Management Strategy
!
Consultation with the affected property owners and with the Water Management
Committee.
Groundwater Recharge
Another environmental reuse opportunity is the use of stormwater and reclaimed water to
recharge groundwater aquifers. Implementing this type of opportunity would be heavily
dependent on having favourable aquifer conditions.
Extensive groundwater investigations to prove the suitability of the aquifer and to establish
design parameters would be essential before considering this reuse opportunity. Areas
where the opportunity may be viable include South Durras and Broulee.
When evaluating if the Broulee and South Durras Aquifers are appropriate for water storage
and reuse, consideration needs to be given to the designated beneficial uses for the
groundwater. The designated beneficial uses such as irrigation and ecosystem support are
determine from:
!
Background groundwater quality, taking into consideration the National Water
Quality Management Strategy (1992) which specify guideline values for water
quality parameters for different beneficial uses and
!
Local historical and continuing uses of those aquifers where these differ from
national and state guidelines.
Further information on aquifer storage and recovery can be found in the report by the
Centre For Groundwater Studies (2000)
Costs
The costs for the Northern and Southern reuse schemes are presented in Table 8-13.
Table 8-13 Costs for the Regional Reclaimed Water Scheme
8.5
8.5.1
Capital ($1000)
NPV 7% ($m)
Northern Scheme
4 842
5 769
Southern Scheme
10 500
11 415
Regional Integrated Water Cycle Management Options
Overview
Having evaluated the range of water resource opportunities using the IWCM process, the
next step involves combining these opportunities to form integrated water resources
options. These are developed for both the regional water scheme, and for each
village/town.
Traditionally, water utilities have focused on developing greater supply sources to meet the
growing water needs and community expectations. These strategies have been based on
traditional engineering solutions such as developing facilities for supply, treatment, storage
and distribution. With the emphasis solely on maintaining reliable water supplies, little
consideration has been given to the environment.
It has been assessed that on balance, higher protection of the river flows of the existing
supply sources in the future is preferable (i.e. 95/30 environmental flow regime until 2020
98
Eurobodalla Integrated Water Cycle Management Strategy
and 80/30thereafter). In addition, if in the future off-river storage is required it would be
more feasible to construct a facility in the south of the shire to harvest and store high flows
of the Tuross River. Modelling has revealed that with the implementation of the immediate
and short term measures, based on existing supply sources the regional scheme would be
th
able to meet a water demand of 6 400 ML/a while providing 95 percentile low flow
th
protection. Future implementation of 80 percentile low flow would reduce secure yield of
the supply system to 4 500 ML/a and necessitate the provision of additional water storage to
maintain supply during droughts. The integrated options described below are based on new
off-river storage in the south of the shire being implemented by 2020.
Table 8-14 below shows how the various opportunities could be bundled to form integrated
options to meet the projected year 2032 water needs.
Table 8-14 Regional Water Supply Integrated Options
Integrated options
Traditional
1
2
3
4
5
6
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
Non-potable water in
new developments
(dual reticulation)
"
"
Aquifer recharge for
subsequent nonpotable water use
"
"
Limited Demand Management
"
Comprehensive Demand Management
10 kL rainwater tanks in all new
developments and 20% existing
houses
Provision of reticulated water supply to
high priority villages
"
Provision of reticulated water supply to
low priority villages
"
Agriculture
Reclaimed
Water Reuse
"
Environmental flow
substitution
Southern dam for the regional scheme
(x 1000 ML)
8.5.2
7
"
5.6
1.5
0.9
0.93
1.01
1.01
0.84
0
Description of the Regional Water Supply Integrated Options
Traditional
This option consists of:
!
Immediate and short term measures as discussion in section 8.3.3. Initially the
northern and southern filtration plants would be 45 ML/d and 15 ML/d respectively
!
A waterwise education program
!
Provision of reticulated water supply to high priority villages
!
Provision of reticulated water supply to low priority villages
!
Maximised reclaimed water reuse for agriculture
99
Eurobodalla Integrated Water Cycle Management Strategy
!
A southern dam (5 600 ML).
Integrated Option 1: Enhance Existing Supply Scheme Plus Southern Dam and
Comprehensive Demand Management
This option consists of:
!
Immediate and short term measures as discussion in section 8.3.3. The initial
capacity of northern and southern filtration plants would be 26 ML/d and 10 ML/d
respectively.
!
A comprehensive demand management comprising:
!
−
Community education targeting outdoor irrigation
−
A active program to retrofit water efficient fittings and equipment, such as
shower roses and aerated taps
−
Pricing adjustments
−
Active system leak detection and repair
A southern dam (1 500 ML).
Integrated Option 2: Enhanced Existing Supply Scheme Plus Southern Dam,
Comprehensive Demand Management and Rainwater Tanks
This option consists of:
!
Immediate and short term measures as discussion in section 8.3.3. The initial
capacity of northern and southern filtration plants would be 24.5 ML/d and 9.5 ML/d
respectively.
!
A comprehensive demand management comprising:
−
Community education targeting outdoor irrigation
−
A active program to retrofit water efficient fittings and equipment, such as
shower roses and aerated taps
−
Pricing adjustments
−
Active system leak detection and repair
!
10 kL rainwater tank for all new developments with water used for garden watering,
toilet flushing and washing machines, and a retrofit of 10 kL rainwater tanks in 20%
of existing houses
!
A southern dam (900 ML).
Integrated Option 3: Option 2 plus Reticulated Water to High Priority Villages
This option consists of:
!
100
Immediate and short term measures as discussion in section 8.3.3. The initial
capacity of northern and southern filtration plants would be 24.5 ML/d and 9.5 ML/d
respectively.
Eurobodalla Integrated Water Cycle Management Strategy
!
10 kL rainwater tank for all new developments with water used for garden watering,
toilet flushing and washing machines, and a retrofit of 10 kL rainwater tanks in 20%
of existing houses
!
A comprehensive demand management comprising:
−
Community education targeting outdoor irrigation
−
A active program to retrofit water efficient fittings and equipment, such as
shower roses and aerated taps
−
Pricing adjustments
−
Active system leak detection and repair
!
Provision of reticulated water supply to high priority villages
!
A southern dam (930 ML).
Integrated Option 4: Enhanced Existing Supply Scheme Plus Southern Dam, Demand
Management, Rainwater tanks and Reticulated Water to All Villages
This option consists of:
!
Immediate and short term measures as discussion in section 8.3.3. The initial
capacity of northern and southern filtration plants would be 25 ML/d and 9.5 ML/d
!
A comprehensive demand management comprising:
−
Community education targeting outdoor irrigation
−
A active program to retrofit water efficient fittings and equipment, such as
shower roses and aerated taps
−
Pricing adjustments
−
Active system leak detection and repair
!
10 kL rainwater tank for all new developments with water used for garden watering,
toilet flushing and washing machines, and a retrofit of 10 kL rainwater tanks in 20%
of existing houses
!
Provision of reticulated water supply to high priority villages
!
Provision of reticulated water supply to low priority villages
!
A southern dam (1 010 ML).
Integrated Option 5: Option 4 plus Agricultural Reuse
This option consists of:
!
Immediate and short term measures as discussion in section 8.3.3. The initial
capacity of northern and southern filtration plants would be 25 ML/d and 9.5 ML/d
!
A comprehensive demand management comprising:
−
Community education targeting outdoor irrigation
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Eurobodalla Integrated Water Cycle Management Strategy
−
A active program to retrofit water efficient fittings and equipment, such as
shower roses and aerated taps
−
Pricing adjustments
−
Active system leak detection and repair
!
10 kL rainwater tank for all new developments with water used for garden watering,
toilet flushing and washing machines, and a retrofit of 10 kL rainwater tanks in 20%
of existing houses
!
Provision of reticulated water supply to high priority villages
!
Provision of reticulated water supply to low priority villages
!
Opportunistic reclaimed water reuse for agriculture
!
A southern dam (1 010 ML)
Integrated Option 6: Option 5 Plus Dual Reticulation and Aquifer Recharge
This option consists of:
!
Immediate and short term measures as discussion in section 8.3.3. The initial
capacity of northern and southern filtration plants would be 24 ML/d and 9 ML/d
!
A comprehensive demand management comprising:
−
Community education targeting outdoor irrigation
−
A active program to retrofit water efficient fittings and equipment, such as
shower roses and aerated taps
−
Pricing adjustments
−
Active system leak detection and repair
!
10 kL rainwater tank for all new developments with water used for garden watering,
toilet flushing and washing machines, and a retrofit of 10 kL rainwater tanks in 20%
of existing houses
!
Provision of reticulated water supply to high priority villages
!
Provision of reticulated water supply to low priority villages
!
Opportunistic reclaimed water reuse for agriculture
!
Reclaimed water reuse for aquifer recharge for subsequent non-potable water use
(e.g. Broulee)
!
Reclaimed water reuse for non-potable water use in new developments (dual
reticulation) for 1 200 houses (e.g. Rosedale)
!
A southern dam (840 ML)
Integrated Option 7: Option 6 Plus Environmental Flow Substitution
This option consists of:
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Eurobodalla Integrated Water Cycle Management Strategy
!
Immediate and short term measures as discussion in section 8.3.3. The initial
capacity of northern and southern filtration plants would be 23.5 ML/d and 9 ML/d
!
A comprehensive demand management comprising:
−
Community education targeting outdoor irrigation
−
A active program to retrofit water efficient fittings and equipment, such as
shower roses and aerated taps
−
Pricing adjustments
−
Active system leak detection and repair
!
10 kL rainwater tank for all new developments with water used for garden, toilet
flushing and washing machines, and a retrofit of 10 kL rainwater tanks in 20% of
existing houses
!
Provision of reticulated water supply to high priority villages
!
Provision of reticulated water supply to low priority villages
!
Opportunistic reclaimed water reuse for agriculture
!
Reclaimed water reuse for aquifer recharge for subsequent non-potable water use
!
Reclaimed water reuse for non-potable water use in new developments (dual
reticulation)
!
Environmental flow substitution in the Moruya River upstream of irrigators on a
greater than 1:3 dilution basis
!
Non-potable water reuse for garden watering and toilet flushing in new
developments and/or by injecting reclaimed water into the aquifer near Broulee for
subsequent use by the householders through their individual spear points.
Analysis shows that this will defer the need for the southern dam. Analysis indicates that the
Southern dam will be needed between year 2035 and 2040.
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Table 8-15 TBL Assessment for the Regional Water Supply Options
Trad.
Integrated Options
0
1
2
3
4
5
6
7
Ensures the efficient use of the
fresh water resource
0
1
2
2
2
3
3
3
Minimises water extractions and
protects low flows
0
1
2
2
2
3
3
3
Minimises greenhouse gas
emissions
1
3
3
2
1
1
1
2
Minimises pollutants being
discharged to the aquatic
environment
0
0
0
0
0
2
2
2
Minimises urban stormwater
volumes
0
0
2
2
2
2
2
2
Ensure sustainable practices
0
1
2
2
2
3
3
3
Environmental Sum
2
6
11
10
9
14
14
15
Environmental Rank
8
7
4
5
6
2
2
1
Improves security of town water
supply
3
3
3
3
3
3
3
3
Improves the quality of drinking
water
3
3
3
3
3
3
3
3
Improves urban water service
levels
1
1
2
2
3
3
3
3
Increases public awareness of
urban water issues
0
2
3
3
3
3
3
3
Minimises non-compliance to
legislation
0
1
1
2
3
3
3
3
Protects public health
0
0
0
2
3
3
3
3
Social Sum
7
10
12
15
18
18
18
18
Social Rank
8
7
6
5
1
1
1
1
149.1
64.2
73.2
74.7
76.8
86.3
86.8
80.7
Financial Rank
8
1
2
3
4
6
7
5
TBL Sum
24
15
12
13
11
9
10
7
TBL Rank
8
7
5
6
4
2
3
1
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV $m over 30 years (with
Rainwater Tanks)
From the triple bottom line assessment, integrated option 7 provides the best social,
environmental and financial outcomes. This option eliminates the need for a dam within the
next 30 years through the integration of options including rainwater tanks, comprehensive
demand management and environmental flow substitution.
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9 Local Water Management
Opportunities
9.1
Introduction
Eurobodalla Shire is comprised of 15 towns and villages. IWCM strategies have been
proposed for each town and village to address the local landscape, water services and
community issues.
Although community presentation and information sessions were undertaken as part of this
study process, it is generally accepted that these sessions were more regionally focused
and therefore were held at the major urban areas. Thus further consultation will be
undertaken at various villages to gain a greater focus on local issues and management
strategies before any option is selected as the preferred solution for the respective
community.
The ranking process used for the TBL assessment is based on scoring each integrated
option from 0-3. The score is based on the appropriateness of each option in achieving the
specified environmental, social and economic criteria, with 0 representing a poor outcome
and 3 representing the most appropriate option. Equal weighting is given to the
environmental, social and economic criteria.
It is important to note that the discrepancies in the data between dwelling numbers and onsite sewerage systems is due to the data originating from two differing sources, namely the
ABS and Council’s Geographical Information Systems (GIS). The discrepancy can be
attributed to unregistered on-site systems and properties having more than one on-site
facility, and the ABS having collection districts different to the village areas.
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9.2
9.2.1
South Durras
Background
The Village Landscape
South Durras is located in the most north easterly part of the shire. The village is divided
into two main regions, the area south of Durras Lake (an intermittently opening lagoon) and
the area behind the dunes, north-west of Mill Point headland. Urban development is
predominantly concentrated on the foreshores of the Tasman Sea. Access to the village is
from the Princes Highway through South Durras Road, see Figure 9-1 below.
Figure 9-1 South Durras Location
The area surrounding the village consists of sensitive wetlands, Murramarang National Park
and coastal dunes and lakes. These areas act as a natural barrier making it difficult to
expand the current footprint/boundary of the village. However, South Durras contains about
59 vacant lots, which once developed, will reach the maximum dwelling numbers. Council’s
current planning instruments only allow single dwelling developments and require the
development to blend with the natural landscape to minimise the impacts on land and water
management. It is the community expectation that this urban setting/characteristic will be
retained in the future. The village also has three caravan parks and a small commercial
area. South Durras has a population of 326 and 313 houses (ABS 2001). This population
almost doubles during the peak summer holiday season. The 1996 housing monitor
indicated that the vacant lots are being developed at an annual rate of 8. Based on this
figure all vacant lots will be developed by 2005.
Existing Water Management Systems
The village residents rely on rainwater tanks for their potable water needs. Some residents
also extract groundwater using private backyard bores to water their gardens. The caravan
parks use both the harvested roof rain runoff and private bores to meet their water needs.
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Eurobodalla Integrated Water Cycle Management Strategy
During periods of drought and low rainfall the individual property owners purchase water
externally, which in most instances is sourced from the shire’s regional water scheme.
The village residents’ sewerage needs are serviced by their own on-site wastewater
management systems. Council’s GIS records show that there are about 296 on-site
treatment facilities. Of these, 74% are septic tanks with effluent disposal by adsorption
trench and an additional 20% are septic tanks with effluent pump-out. Property owners
arrange for their own septic tank pumpout, which in most instances is treated in one of the
sewage treatment plants in the Shire. The remaining 6% of the systems utilise aerated
processes with on-site effluent irrigation that give higher levels of nutrient removal than
septic systems.
The village has two stormwater catchments. Most of the catchment area is pervious with
underlying sandy soils. Therefore surface runoff is negligible and confined to the roads
within the village. The first catchment drains to Durras Lake and the second catchment to
the sea. There are about 0.97 km of stormwater pipeline and 57 pits along the village roads
that predominantly carry the runoff from the roads.
Figure 9-2 Aerial Photograph of South Durras
9.2.2
What Are the Issues?
The issues associated with the South Durras landscape and water management system
are classified into environmental and social issues, and are discussed below. Other
community services related issues are not included as part of this study.
Environmental Issues
!
Acid sulfate soils exposed from past development are impacting on the water
quality of the lake.
!
The groundwater levels and the extraction rates are not monitored. Anecdotal
evidence suggests that the water level falls during long periods of no rain. However
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Eurobodalla Integrated Water Cycle Management Strategy
no analysis has been undertaken to quantify the sustainability of current
extractions.
!
Due to the sandy nature of the soil it is commonly acknowledged that
sewage/effluent from on-site wastewater management systems will infiltrate the
groundwater aquifer and ultimately end up in the waterways, in this instance into
Durras Lake. This is not acceptable given the comprehensive protection
classification given to Durras Lake by the Independent Inquiry Into Coastal Lakes
(HRC, 2001).
!
Groundwater quality results (taken in mid-1980s) show elevated nitrate levels and
the presence of faecal bacteria confirming the contamination of the groundwater
from poorly managed on-site wastewater management systems. No additional
water quality information is available due to the lack of a monitoring program.
!
Stormwater entering the lake from the developed area may also impact on the
health and visual quality of the lake. The likely pollutants are hydrocarbons from the
roads, litter particularly from the hot spots (e.g. caravan park and commercial area),
and nutrients and particles associated with the sediments. In the absence of
stormwater quantity and quality monitoring, preliminary estimates suggest an
annual flow of 565 kL, with corresponding nitrogen and phosphorus loads of 680 kg
and 90 kg respectively.
!
Degradation of sensitive natural wetlands from stormwater discharge and the
invasion of exotic weeds.
Social Issues
9.2.3
!
Due to the popular nature of the village and its surrounds, there are concerns that
development density will increase or the village footprint will be expanded.
!
Dependence on rainfall has, at times, reduced the reliability of the individual water
systems.
!
Current on-site wastewater management practices are posing a public health risk
particularly during rainy periods.
!
South Durras records the highest number of complaints relating to on-site
wastewater management in the shire.
!
There is no formal approach to stormwater management in the village to promote
the better management and efficient use of this resource.
!
The village residents do not receive ‘tips’ on how to save water and on how to
better manage their on-site wastewater systems.
!
There is no local water provision to fight building fires within the village.
How Do We Fix the Problems?
Overview
South Durras’s water cycle needs to be managed sustainably. This could be achieved
through the implementation of appropriate planning controls. The issues of future
development and acid sulfate soil runoff could be managed by amending the Local
Environmental Plan and development control plans. For instance South Durras is opposed
to the provision of a reticulated water and sewerage system, citing that this will allow the
zoning of the village to change and may result in more medium density development.
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However, zoning and development control plans could be used to maintain the village’s
character.
The management of Durras Lake requires a coordinated management approach by both
Eurobodalla and Shoalhaven councils as the local government boundary splits the lake into
two; South and North Durras. Further, although not discussed in this strategy, there could
be opportunity for integrated and joint management of the water cycle in both villages, as
well as the opportunity for the two councils to develop a joint local environmental plan.
There are a number of opportunities available to manage the water cycle of South Durras.
Traditionally, all opportunities available for the water supply, wastewater and stormwater
were often evaluated in isolation. In this strategy, all available opportunities were identified
and coarse screened (see appendix C). The short-listed water cycle management
opportunities are discussed below.
Water Cycle Management Opportunities
There are both short and medium term measures to improve the water cycle management
at South Durras. The short term measures should be implemented as a matter of priority to
achieve best practice standard immaterial of the medium term opportunities.
Short term Measures
The short term measures include:
!
Identification of all private bores and improving the sustainability of the current
aquifer usage including regular water quality and water level monitoring.
!
Regular monitoring of the on-site wastewater management systems for
performance and integrity.
!
Systematic monitoring of the local waterways and the urban stormwater quality and
quantity.
!
Regular mail-outs of ways to maintain on-site water and wastewater systems
including information on water conservation.
The above short term measures are complimentary to the proposed medium-term
measures and would help Council and the community to manage their water cycle more
sustainably.
Medium to Long term Water Cycle Management Opportunities
Medium-term opportunities are measures related to improving the long term sustainability
of the water cycle. In addition, these opportunities will also reduce the public health and
environmental impacts and enhance the service standards for the water services. The table
below presents these opportunities along with their capital and present value at an annual
discount rate of 7%.
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Table 9-1 Integrated Water Cycle Management Opportunities for South Durras
Cost Estimate
Capital ($m)
NPV @ 7% ($m)
-
2.0
Local water source
1.6
2.3
Regional water source
2.1
2.3
Local water source
2.0
2.6
Regional water source
2.4
2.7
Improved management of existing on-site facilities
0.49
2.7
Enhanced management of existing on-site
facilities
1.42
1.79
Enhanced management of existing on-site
facilities with greywater reuse
3.5
5.0
Centralised management of effluent from on-site
facilities with local treatment
3.19
2.49
Local treatment and
management
3.26
2.53
Transfer to Batemans
Bay system
3.46
2.50
Improved management of existing water supply
Harvested roof water
supplemented with
reticulated water
Provision of full
reticulated water
system
Provision of full
reticulated sewerage
system
Note: NPV’s for on-site systems are based on a rolling program commencing in 2003. NPV’s for sewering South
Durras are based on work commencing in 2009. NPV’s for water are based on work commencing in 2003
Improved Management of Existing Water Supply
Conserving water and using it more efficiently could improve the reliability of the existing
rainwater tank supply. This may be achieved through utilising water efficient appliances and
fixtures such as dual flush toilet, aerated taps, smart and efficient shower roses and
washing machines. Improved reliability could also be achieved by utilising groundwater
obtained from backyard bores for toilet flushing, clothes washing and garden watering. The
water quality from rainwater tanks could be improved through better management practices
such as by installing a first flush device, a coarse filter at the inlet and by regular cleaning.
Harvested Roofwater Supplemented with Reticulated Water
This opportunity continues to utilise existing rainwater tanks for toilet flushing and garden
watering, with a supplemented reticulated water supply for other potable purposes and to
top up the rainwater tanks when needed. This option would eliminate the need to import
water in periods of low rainfall and drought, and would provide water that meets the
Australian Drinking Water Guidelines. The reticulated water could be sourced either:
!
Locally from the coastal aquifer, or
!
From the regional scheme.
In both cases, the reticulation pipes required would be smaller than that required for the
provision of a full reticulated water supply. In this case the average annual and peak
reticulated water demands for the full development situation would be about 68 ML/a and
0.22 ML/d respectively.
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Eurobodalla Integrated Water Cycle Management Strategy
Water sourced from the local bore is likely to have a low pH and be high in iron. The nitrate
value of 4 mg/L recorded in mid-1980s, although high, is still within the recommended
Australian Drinking Water Guidelines. Thus bore water would be required to undergo basic
treatment consisting of aeration followed by filtration. A reticulation scheme based on a
local source would consist of a borefield with at least two bores, a water filtration facility, a
small reservoir, pumping facilities and 50 mm reticulation pipes.
The alternative option of sourcing water from the regional scheme would require a pumping
facility at Batemans Bay, 14 km raising/gravity main, a small reservoir, and approximately
50 mm reticulation pipes.
In both cases no fire fighting provision will be provided in the reticulation pipes.
Provision of Full Reticulated Water Supply
Rainwater tanks can be less reliable than town water supplies and if gutters, roof surfaces
and tanks are not well maintained the resulting water quality may be of a considerably
poorer quality than that from a full reticulated town water supply. A full reticulated system
without the reliance on rainwater tanks would eliminate the need for homeowners to import
water during low rainfall and drought periods, and would provide water that meets the
Australian Drinking Water Quality Guidelines.
Similar to the previous opportunity reticulated water could be sourced from the:
!
Local coastal aquifer, or
!
Regional scheme.
In this case the average annual and peak reticulated water demands for the full
development situation would be about 80 ML/a and 0.33 ML/d respectively.
The scheme facilities required for both the source water options would be similar to those
required in the previous opportunity, except the facility and component sizes will be slightly
larger. The provision of larger pipes and facilities enables the provision of urban fire fighting
services at minimal extra cost.
Improved Management of Existing On-site Wastewater Facilities
The seepage from existing on-site wastewater management systems could be reduced by
regularly emptying the contents of the septic tanks and installing monitoring systems to
prevent septic tank overflows and to allow for the ongoing assessment of the integrity of the
tanks.
A single contract could be arranged by the Council or by the community such that the septic
tanks are pumped at set time intervals. This would cover both effluent and sullage
pumpout. The pumpout cost could be evenly divided among the residents. To facilitate
pumping every tank would require a small holding tank or pumpout facility.
This opportunity would eliminate the risk of effluent contaminating the aquifer and
waterways. Potential disadvantages include odours and noise during pumpouts and the
frequent movement of trucks in the neighbourhood.
Enhanced Management of Existing On-site Wastewater Facilities
There are several options available to upgrade the existing on-site wastewater
management systems to achieve greater public health and environmental outcomes. The
first option is to retain the existing septic tank and upgrade the on-site effluent management
system. An example of this would be the replacement of the adsorption trenches with lined
evapotranspiration beds that achieve a higher level of water and nutrient uptake through
plants.
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Eurobodalla Integrated Water Cycle Management Strategy
Another alternative is to upgrade the septic system to one that achieves nutrient removal
and therefore results in a higher quality effluent discharge (e.g. aerated tanks). This would
increase the potential uses available for the resulting treated effluent.
Both these options would minimise the potential of groundwater contamination and its
associated environmental impacts, as well as reducing the likelihood of public health issues
and odour complaints.
Enhanced Management of Existing On-site Facilities with Greywater Reuse
In this opportunity blackwater (water from kitchen sink and toilet), and greywater (water
from laundry and bathroom), would be managed separately. The blackwater would be
treated in the existing septic tanks with regular pumpouts and the greywater would be
treated on-site using an advanced technology such as aerated tanks. The treated effluent
could then be recycled for garden watering and toilet flushing.
In addition to reducing the amount of imported reticulated water, this would conserve
harvested roof rainwater. With the implementation of an appropriate monitoring system,
long term environmental and water resource sustainability and public health protection
could be achieved.
Centralised Management of Effluent from On-site Facilities
As an alternative to providing a full reticulated sewage system, the effluent from existing onsite systems (e.g. septic tanks) could be collected and transported to a central treatment
facility. This type of system relies on smaller pipes than those required for a conventional
reticulated sewerage system. Pipes can be laid in the ground at a lesser gradient and at a
more shallow depth than that of conventional gravity sewerage, as the pipes carry only
liquid effluent. The solids are captured by the on-site system.
The effluent could be treated locally or transported to Batemans Bay STP. Appendix P
provides information on the various effluent transport and local treatment options.
Treating effluent at a local facility would result in a number of options for the management
of reclaimed water. Preliminary appraisal suggests dunal infiltration, agricultural reuse
(possibly at the Princess Highway) and controlled groundwater injection for subsequent
extraction as the most suitable options worthy of further evaluation.
Costs in Table 9-1 are based on centralised effluent drainage (CED) for transport, a local
package plant for treatment and dunal infiltration.
Provision of Full Reticulated Sewerage System
An alternative to on-site treatment facilities is to transfer wastewater (i.e. black and
greywater) through a centralised sewer transport network to either a local treatment facility
as discussed for the previous opportunity or to the Batemans Bay treatment works. Unlike
the previous opportunity, the sewer transport pipes would need to be larger and possibly
installed at greater depths.
Appendix P provides a detailed description of the available transport and local treatment
options. The shortlisted reclaimed water management options are the same as those
discussed for the above opportunity.
Costs in Table 9-1 are based on a modified gravity transport system, a local package
extended aeration treatment plant and dunal infiltration.
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Eurobodalla Integrated Water Cycle Management Strategy
Social and Environmental Aspects of Medium to Long Term Water Cycle
Management Opportunities
The TBL assessment (Table 9-2) provides the comparative environmental and social
benefits of each water cycle management opportunity.
Table 9-2 Social and Environmental Aspects of the Medium to Long Term
Opportunities for South Durras
Opportunity
Improved management of existing
water supply
Social
Reduces demands for water and
increases security
Increases public awareness of
water conservation issues
Decreases public health risks
and increases security
Local water
source
Eliminates the need to import
water
Water for potable uses would
meet the Australian Drinking
Water Guidelines
Harvested roof
water
supplemented
with reticulated
water
Decreases public health risk and
increases security
Regional water
source
Eliminates the need to import
water
Water for potable uses would
meet the Australian Drinking
Water Guidelines
Environmental
More conservative/efficient use
of water.
Incorporates sustainable use of
water resources
Water extraction could place
pressure on the local aquifer
and the environment
Incorporates sustainable use of
water resources
Reduces pressure on the local
aquifer
Less pressure on local
environments, however
increases pressure on regional
water sources
Decreases public health risk and
increases security
Eliminates the need to import
water
Local water
source
Provision available for fire
fighting purposes
Short term inconvenience for
residents during construction,
i.e. noise, vehicle movement
Water for potable uses would
meet the Australian Drinking
Water Guidelines
Provision of full
reticulated water
system
Water extraction could place
pressure on the local aquifer
and the environment
Increases runoff, which may
result in increased pollutant
loads entering the environment
Possible environmental impact
during construction
Decreases public health risk and
increases security
Eliminates the need to import
water
Regional water
source
Provision available for fire
fighting purposes
Short term inconvenience for
residents during construction,
i.e. noise, vehicle movement
Water for potable uses would
meet the Australian Drinking
Water Guidelines
Improved management of existing onsite facilities
Associated odour and noise
impacts
Inconvenience of pumpout
trucks in the area
Less pressure on local
environments, however
increases pressure on regional
water sources
Increases runoff, which may
result in increased pollutant
loads entering the environment
Possible environmental impact
during construction
Improves environmental
outcomes, minimises the
incidence of septic effluent
contaminating groundwater
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Eurobodalla Integrated Water Cycle Management Strategy
Opportunity
Social
Environmental
Improves air quality and visual
character
Enhanced management of existing onsite facilities
Enhances aesthetic appeal for
the local area, good for tourism
and recreational activities
Reduces impact to local aquifer
and the environment
Improves air quality and visual
character
Enhanced management of existing onsite facilities with greywater reuse
Potential disturbance during
construction period
Enhances aesthetic appeal for
the local area
Reduces impact to local aquifer
and the environment
Maximises water resource use
Decreases demand for water,
increases security
Local treatment
and
management
Centralised
management of
effluent from onsite facilities
Transfer to
Batemans Bay
system
Solution would be tailored to
match local requirements
Potential short term disturbance
during construction period
Less overall environmental
impacts than conventional
gravity systems
Limited additional treatment
infrastructure required
Possible environmental impact
during construction
Existing resources can be
utilised
Less overall environmental
impacts than conventional
gravity systems
Potential short term disturbance
during construction period
Solution would be tailored to
match local requirements
Local treatment
and
management
Provision of full
reticulated
sewerage system
9.2.4
Larger capital investment
required
Short term inconvenience for
residents during construction i.e.
noise, vehicle movement
Limited additional treatment
infrastructure required
Transfer to
Batemans Bay
system
Would encourage local reuse
and recycling
Existing resources can be
utilised
Short term inconvenience for
residents during construction i.e.
noise, vehicle movement
May allow for regional reuse
Improves quality of effluent
discharged to environment
Increases opportunities for
effluent reuse
Possible environmental impact
during construction
Significantly reduces likelihood
of groundwater contamination
Improved quality of effluent
discharged to environment
Increased opportunities for
effluent reuse
Possible environmental impact
during construction
Significantly reduced likelihood
of groundwater contamination
Integrated Water Cycle Management Scenarios
Using the bundling process, the above water management opportunities can be combined
into integrated scenarios. Table 9-3 presents examples of integrated scenarios. Other
scenarios may be developed and considered in subsequent study phases.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-3 Integrated Scenarios for South Durras
Minimal
Improved management of existing water
supply
Harvested roof
water
supplemented with
reticulated water
Local water source
Provision of full
reticulated water
system
Local water source
Traditional
Solution
3
5
"
"
"
Regional water
source
"
"
Enhanced management of existing on-site
facilities
"
Enhanced management of existing on-site
facilities with greywater reuse
"
Centralised management of effluent from
on-site facilities with local treatment
Provision of full
reticulated
sewerage system
4
"
Regional water
source
Improved management of existing on-site
facilities
Integrated Scenarios
"
Local treatment and
management
Transfer to
Batemans Bay
system
"
Minimal Improved management of existing water supply and improved management of existing onsite facilities.
Traditional Provision of reticulated water systems from the regional supply, and the provision of full
reticulated sewerage systems with transfer to the Batemans Bay system.
Integrated Scenario 3 Harvested roof water supplemented with reticulated water from the regional
supply, and centralised management of effluent from on-site facilities with local treatment and
management.
Integrated Scenario 4 Harvested roof water supplemented with reticulated water from a local supply
source and enhanced management of existing on-site facilities.
Integrated Scenario 5 Harvested roof water supplemented with reticulated water from a local supply
source and enhanced management of existing on-site facilities with greywater reuse.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-4 Triple Bottom Line Reporting for South Durras
Minimal
Traditional
Approach
3
4
5
Efficient use of fresh water
resource
3
1
2
3
3
Minimises low flow water
extractions
3
1
2
3
3
Minimises greenhouse gas
emissions
3
1
1
2
2
Minimises pollutants being
discharged to the aquatic
environment
2
2
2
2
2
Minimises urban stormwater
volumes
3
0
2
2
2
Ensures sustainable practices
2
1
1
2
3
Environmental Sum
16
6
10
14
15
Environmental Rank
1
5
4
3
2
Improves security of town water
supply
0
3
3
3
3
Improves the quality of drinking
water
1
3
3
3
3
Improves urban water service
levels
1
3
3
3
3
Increases public awareness of
urban water issues
3
1
2
3
3
Minimises non-compliance to
policy and legislation
1
3
3
3
3
Protects public health
1
3
3
3
3
Social Sum
7
16
17
18
18
Social Rank
5
4
3
1
1
$2.8
$5.0
$4.8
$3.59
$6.80
Financial Rank
1
4
3
2
5
TBL Sum
9
13
10
6
8
TBL Rank
3
5
4
1
2
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV ($m over 30 years)
Using the criteria above Option 4, harvested roof water supplemented with reticulated water from
a local supply source and enhanced management of existing on-site facilities is the preferred
solution. This option performs well in all of the three TBL categories.
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9.3
9.3.1
Nelligen
Background
The Village Landscape
Nelligen is located on the brackish reaches of the Clyde River, which has been identified as
a high value catchment. The 2001 census recorded 219 people in Nelligen. The 1996
housing monitor stated there were 58 vacant lots in Nelligen, with an annual demand of 3
lots. This analysis indicates that there will be a land shortage in the village in 2015. Figure
9-3 contains a locality diagram of Nelligen.
Figure 9-3 Nelligen Location
Existing Water Management Systems
Nelligen is not connected to the regional town water supply and depends solely on water
from rainwater tanks. Sewage is also treated on site. According to the GIS, there are 95 onsite treatment systems in the village. 81% of these are septic tanks with effluent disposal by
adsorption trench, and an additional 14% are septic tanks with effluent pumpout. The
remaining systems utilise aerated processes that give higher levels of nutrient removal.
Being located on the Clyde River, stormwater discharge from Nelligen can impact adversely
on water quality in this high conservation value catchment. Stormwater issues for the village
have not been identified in the stormwater quality management plan due to the village’s
size. Only one stormwater pipe has been identified on the GIS. Figure 9-4 shows the
stormwater catchments for Nelligen.
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Figure 9-4 Aerial Photograph of Nelligen
9.3.2
What are the Issues
The issues associated with the village landscape and water management system are
classified into environmental and social issues, and are discussed below. Other community
services-related issues are not part of this study.
Environmental Issues
!
Stormwater from the developed area may impact on the health and visual quality of
the river. In the absence of stormwater quantity and quality monitoring, preliminary
estimates suggest 400 kL/a of stormwater is generated in Nelligen, containing
480 kg of nitrogen and 64 kg of phosphorus.
!
The current on-site management practices may pose environmental risks, due to
overflows, less than ideal soil types, the slope of the land and oyster farming
downstream from Nelligen.
Social Issues
118
!
The current residents would support the provision of water and sewerage services
as it would allow further development of the village
!
The current on-site management practices may pose a potential public health risk
!
The community does not have access to a secure water supply
!
The area has a high tourist load
!
The river is popular with recreational visitors for such activities as water skiing and
fishing
!
Oyster farming is undertaken downstream of Nelligen.
Eurobodalla Integrated Water Cycle Management Strategy
9.3.3
How Do We Fix the Problems
Overview
It is vital that water management be undertaken in a sustainable manner. One important
mechanism to aid in the achievement of sustainable water management is through planning
controls. Many social and environmental issues such as protecting the amenity and medium
density housing can be addressed through a local environmental plan or development
control plan. Consultation meetings have shown that the community supports further
development in Nelligen. Ensuring this development is undertaken in a sustainable manner
is best achieved through strategic planning via planning instruments. Planning instruments
also provide a forum for public review and participation requiring a mandatory exhibition and
submission period.
The traditional approach to water management is to separate water, wastewater and
stormwater and treat each in isolation. In this strategy, all available opportunities have been
identified and coarse screened (see appendix C). The shortlisted water cycle management
opportunities are discussed below.
Water Cycle Management Opportunities
There are both short and medium term measures to improve the water cycle management
at Nelligen. The short term measures should be implemented as a matter of priority to
achieve best practice standard immaterial of the medium term opportunities.
Short term Measures
The short term measures include:
!
Regular monitoring of the on-site wastewater management systems for
performance and integrity
!
Systematic monitoring of local waterways and urban stormwater quality and
quantity
!
Regular mail-outs of ways to maintain on-site water and wastewater systems
including information on water conservation.
The above short term measures are complimentary to the proposed medium-term
measures and would help Council and the community to manage their water cycle more
sustainably.
Medium to Long term Water Cycle Management Opportunities
Medium-term opportunities are measures related to improving the long term sustainability
of the water cycle. In addition, these opportunities will also reduce public health and
environmental impacts and enhance the standards for the water services. The table below
presents these opportunities along with their capital and present value at an annual
discount rate of 7%.
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Table 9-5 Integrated Water Cycle Management Opportunities for Nelligen
Cost Estimate
Capital ($m)
NPV @ 7% ($m)
-
0.06
Harvested roof water supplemented with reticulated water from
the regional scheme
1.5
1.7
Provision of full reticulated water system from the regional
scheme
1.7
1.9
Improved management of existing on-site facilities
0.18
0.96
0.46
0.61
2.83
1.10
Local treatment and management 1
2.89
1.254
1
1.55
0.27
1.55
0.27
Improved management of existing water supply
Enhanced management of existing on-site facilities
1
Centralised management of effluent from on-site facilities with
local treatment 1
Provision of full
reticulated sewerage
system
Transfer to Batemans Bay system
Transfer to Batemans Bay system
with greywater reuse 2
Note 1: NPV’s for on-site systems are based on a rolling program commencing in 2003. NPV’s for sewering
Nelligen are based on work commencing in 2012. NPV’s for water are based on works commencing in 2003
Note 2: The savings achieved by Council treating less effluent have not been taken take into account in the study
and the costs associated with greywater reuse are community costs
Improved Management of Present Water Supply
The reliability of the existing rainwater tank supply could be improved by conserving water
through more efficient use. Utilising water efficient appliances and fixtures such as dual
flush toilet, aerated taps, smart and efficient shower roses and washing machines are a few
examples.
Harvested Roof Water Supplemented with Reticulated Water
Nelligen is totally dependent upon rainwater tanks for its water supply. Installing a
reticulated system to supplement rainwater supplies would increase the water security. This
type of system would offer a good quality potable water supply whilst continuing to utilise
rainwater tanks for uses such as toilet flushing, washing machines and gardening.
Significant community and health benefits would be expected with a supplemented potable
supply meeting the Australian Drinking Water Guidelines. The reticulated water could be
sourced from the regional scheme. This option would also increase security and eliminate
the need to import water in periods of low rainfall.
The pipes required for a supplemented reticulation scheme would be smaller than for a full
reticulated water supply provision. In this case the average annual and peak reticulated
water demands for the full development situation would be about 24 ML/a and 0.13 ML/d
respectively.
Provision of Full Reticulated Water Supply
Rainwater tanks can be less reliable than town water supplies and if gutters, roof surfaces
and tanks are not well maintained they may result in poor quality water. A full reticulated
town water supply with no rainwater tanks would significantly reduce public health risks
through ensuring that the water supply meets the Australian Drinking Water Quality
Guidelines. This option would also eliminate the need for homeowners to import water
during low rainfall and drought periods.
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Eurobodalla Integrated Water Cycle Management Strategy
Connecting Nelligen to the region’s water supply from Batemans Bay would require a pipe
extension of 7.2 km from Batemans Bay along the existing road line. The average annual
and peak reticulated water demands for the full development situation would be about
28 ML/a and 0.20 ML/d respectively.
The scheme facilities necessary to provide a full reticulated water supply to Nelligen would
be similar to those required for a supplemented reticulated supply as discussed previously.
The facility and component sizes will, however, need to be slightly larger. The provision of
larger pipes and facilities enables the provision of fire fighting services at minimal extra
cost.
Improved Management of Existing On-site Wastewater Facilities
Sewage in Nelligen is currently treated by on-site systems. It is recommended that Council
consider the management options for sewage treatment for the village. The seepage from
existing on-site wastewater management systems could be reduced by regularly emptying
the contents of the septic tanks and installing monitoring systems to prevent septic tank
overflows and to assess the integrity of the tanks. Regular pumpouts and monitoring have
the potential to minimise many of the environmental and public health impacts associated
with the operation of septic systems.
A single contract could be arranged by the Council or by the community such that the septic
tanks are pumped at set time intervals. This would cover both effluent and sullage
pumpout. The cost of this pumpout could be evenly split between the residents. To facilitate
pumping every tank would require a smaller holding tank or pumpout facility.
Although this opportunity would reduce the potential of waterway and aquifer contamination,
it may result in additional community impacts, such as odour complaints associated with
pumpouts and the movement of trucks in the neighbourhood.
Enhanced Management of Existing On-site Wastewater Facilities
There are several options available to upgrade the existing on-site wastewater
management systems to achieve greater public health and environmental outcomes. The
first option is to retain the existing septic tank and upgrade the on-site effluent management
system. An example of this would be the replacement of the adsorption trenches with lined
evapotranspiration beds, which achieve a higher level of water and nutrient uptake through
plants.
Another alternative is to upgrade the septic system to one that achieves nutrient removal
and therefore results in a higher quality effluent discharge (e.g. aerated tanks). This would
increase the potential uses available to the resulting treated effluent.
Both these options would minimise the potential of groundwater contamination and its
associated environmental problems, as well as reducing the likelihood of public health
issues and odour complaints.
Centralised Management of Effluent from On-site Facilities
As an alternative to providing a full reticulated sewage system, the effluent from existing onsite systems (e.g. septic tanks) could be collected and transported to a central treatment
facility. This type of system relies on smaller pipes than those required for a conventional
reticulated sewerage system. Pipes can be laid in the ground at a lesser gradient and at a
more shallow depth than that of conventional gravity sewerage, as the pipes carry only
entrained solids thus having minimal self-cleaning velocity requirements.
The effluent could be treated locally or transported to Batemans Bay STP. Appendix P
provides information on the various effluent transport and local treatment options.
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Eurobodalla Integrated Water Cycle Management Strategy
Treating effluent at a local facility would result in a number of options for the management
of reclaimed water. Appendix P provides a detailed description of the available
management options. Preliminary appraisal suggests river disposal, or agricultural reuse as
the most suitable options worthy of further evaluation.
Costs in Table 9-5 are based on centralised effluent drainage (CED) for transport, a local
package plant for treatment and river disposal.
Provision of a Full Reticulated Sewerage System
An alternative to providing any on-site treatment facilities is to transfer wastewater (i.e.
black and greywater) through a centralised sewer transport network to either a local
treatment facility as discussed for the previous opportunity or to the Batemans Bay STP. A
slight variation on this option would be to incorporate local greywater reuse and only
transfer blackwater to the Batemans Bay STP.
Unlike in the previous opportunity, the sewer transport pipes would need to be larger and
possibly installed at greater depths.
Appendix P provides a detailed description of the available transport and local treatment
options. The shortlisted reclaimed water management options are the same as those
discussed for the above opportunity.
Costs in Table 9-5 are based on a modified gravity transport system, a local package
extended aeration treatment plant and river disposal.
Provision of Full System with Greywater Reuse
On-site systems that achieve a suitable level of treatment for greywater would be
maintained, and blackwater only would be transported to the Batemans Bay STP using the
reticulation systems described above. The resulting greywater could then be utilised for a
variety of outdoor uses and for toilet flushing. Maintaining current aerated systems in
Nelligen for greywater reuse would reduce the volume of wastewater requiring treatment by
0.325 ML/a. If in addition, current septic tanks were converted to rainwater tanks for reuse
purposes an additional 3.6 ML/a could be saved. In addition to reducing the volume of
imported or reticulated water required for Nelligen, this would reduce the hydraulic load on
the Batemans Bay STP. With the implementation of appropriate monitoring systems, long
term environmental and water resource sustainability and public health protection could be
achieved.
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Table 9-6 Social and Environmental Aspects of the Medium to Long Term
Opportunities for Nelligen
Opportunities
Improved management of existing
water supply
Social
Reduces demands for water and
increases security
Increases public awareness of
water conservation issues
Environmental
More conservative/efficient
water use
Decreases public health risks
and increases security
Harvested roof water supplemented
with reticulated water from the regional
scheme
Eliminates the need to import
water
Water for potable uses would
meet the Australian Drinking
Water Guidelines
Incorporates sustainable use of
water resources
Increases pressure on regional
water sources
Decreases public health risk and
increases security
Eliminates the need to import
water
Provision of full reticulated water
system from the regional scheme
Provision available for fire
fighting purposes
Short term inconvenience for
residents during construction,
i.e. noise, vehicle movement
Water for potable uses would
meet the Australian Drinking
Water Guidelines
Improved management of existing onsite facilities
Associated odour and noise
impacts
Inconvenience of pumpout
trucks in the area
Less pressure on local
environments, however
increases pressure on regional
water sources
Increases runoff, which may
result in increased pollutant
loads entering the environment
Possible environmental impact
during construction
Improves environmental
outcomes, minimises the
incidence of septic effluent
contaminating local waterways
Improves air quality and visual
character
Enhanced management of existing onsite facilities
Local treatment
and management
Centralised
management of
effluent from onsite facilities
Enhances aesthetic appeal for
the local area, good for tourism
and recreational activities
Solution would be tailored to
match local requirements
Limited additional infrastructure
required
Transfer to
Batemans Bay
system
Lower cost than conventional
gravity
Existing resources can be
utilised
Reduces impact to local
waterways and the environment
Less overall environmental
impacts than conventional
gravity systems
Less overall environmental
impacts than conventional
gravity systems
Possible environmental impact
during construction
May allow for regional reuse
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Eurobodalla Integrated Water Cycle Management Strategy
Opportunities
Social
Generally accepted by the
community
Solution would be tailored to
match local requirements
Local treatment
and management
Larger capital investment
required
Short term inconvenience for
residents during constructions
i.e. noise, vehicle movement
Limited additional treatment
infrastructure required
Provision of full
reticulated
sewerage
Transfer to
Batemans Bay
system
Existing resources can be
utilised
Short term inconvenience for
residents during construction,
i.e. noise, vehicle movement
Environmental
Improves quality of effluent
discharged to environment
Increases opportunities for
effluent reuse
Possible environmental impact
during construction
Significantly reduces likelihood
of river contamination
Improves quality of effluent
discharged to environment
Increases opportunities for
effluent reuse
Possible environmental impact
during construction
Significantly reduces likelihood
of river contamination
Reduces water demand
Reduces hydraulic and
biological load on the Batemans
Bay system
Transfer to
Batemans Bay
system with
greywater reuse
Limited additional treatment
infrastructure required
Existing resources can be
utilised
Improves quality of effluent
discharged to environment
Incorporates sustainable use of
water resources
Reduces demands on water
resources
Short term inconvenience for
residents during construction,
i.e. noise, vehicle movement
9.3.4
Integrated Water Cycle Management Scenarios
Using the bundling process the above water management opportunities can be combined
into integrated scenarios. Table 9-7 presents examples of integrated scenarios.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-7 Integrated Scenarios for Nelligen
Minimal
Improved management of existing water supply
Traditional
Solution
3
4
5
"
"
"
"
Harvested roof water supplemented with
reticulated water from the regional scheme
Provision of full reticulated water system from the
regional scheme
Improved management of existing on-site facilities
Integrated Scenarios
"
"
Enhanced management of existing on-site
facilities
Centralised
management of
effluent from onsite facilities
Provision of full
reticulated
sewerage
system
"
Local treatment and
management
"
Transfer to Batemans Bay
system
Local treatment and
management
Transfer to Batemans Bay
system
Transfer to Batemans Bay
system with greywater reuse
"
"
Minimal Improved management of existing water supply and improved management of existing onsite facilities.
Traditional Provision of full reticulated water systems from the regional supply scheme, and the
provision of full reticulated sewerage systems with transfer to the Batemans Bay system.
Integrated Scenario 3 Harvested roof water supplemented with reticulated water from the regional
supply scheme, and centralised management of effluent from on-site facilities with transfer to a local
treatment plant.
Integrated Scenario 4 Harvested roof water supplemented with reticulated water from the regional
supply scheme and enhanced management of existing on-site facilities.
Integrated Scenario 5 Harvested roof water supplemented with reticulated water from the regional
supply scheme and provision of full reticulated sewerage system, transfer to Batemans Bay with
greywater reuse.
The triple bottom line assessment below presents the comparative environmental, social
and economic benefits of each integrated scenario example.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-8 Triple Bottom Line Assessment for Nelligen
Minimal
Traditional
Approach
3
4
5
Efficient use of fresh water
resource
2
1
2
2
2
Minimises low flow water
extractions
3
1
2
2
3
Minimises greenhouse gas
emissions
3
0
1
2
1
Minimises pollutants being
discharged to the aquatic
environment
2
2
2
2
2
Minimises urban stormwater
volumes
3
0
2
2
2
Ensures sustainable practices
2
1
2
2
3
Environmental Sum
15
5
11
12
13
Environmental Rank
1
5
4
3
2
Improves security of town water
supply
0
3
3
2
3
Improves the quality of drinking
water
1
3
3
3
3
Improves urban water service
levels
1
3
3
3
3
Increases public awareness of
urban water issues
3
1
2
2
3
Minimises non-compliance to
policy and legislation
1
3
3
3
3
Protects public health
1
3
3
3
3
Social Sum
7
16
17
16
18
Social Rank
5
3
2
3
1
0.24
2.17
3.53
2.20
1.97
Financial Rank
1
3
5
4
2
TBL Score
7
11
11
10
5
TBL Rank
2
4
4
3
1
Opportunities
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV ($m over 30 years)
The TBL assessment using the above criteria ranks option 5 as the best scenario for
Nelligen. This option has harvested roof water supplemented with reticulated water from the
regional supply scheme and provision of a reticulated sewerage system, transfer to
Batemans Bay with greywater reuse.
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Eurobodalla Integrated Water Cycle Management Strategy
9.4
9.4.1
Batemans Bay and Surrounds
Background
The Landscape
The town of Batemans Bay is taken to encompass the areas north of Clyde River including
Maloneys Beach, Long Beach, Surfside and North Batemans Bay, the central business
area of Catalina, Batehaven and Sunshine Bay and the southern areas covering Denhams
Beach, Surf Beach, Lilli Pilli and Malua Bay. The north and central urban areas are located
predominantly on the foreshores of Batemans Bay and the southern areas on the
foreshores of the Tasman Sea. Batemans Bay forms part of the Clyde River estuary system
and is an attractive and popular tourist destination. The tidal regions of the river support the
major oyster industry within the Eurobodalla Shire. The township of Batemans Bay is
located near the junction of Princess Highway and Kings Highway (see Figure 9-5 below).
Figure 9-5 Batemans Bay Topographic Map
This area supports about 45% of the total Eurobodalla Shire’s urban population and the
majority of tourist visitors to the shire. During the peak tourist/holiday season, the population
of Batemans Bay almost doubles. The current permanent population of the area is about
17 800 (6 950 dwellings) and is expected to increase to about 23 700 (8 500 dwellings)
within the current planning period. Council has identified that the majority of this population
growth will be accommodated within the zoned urban expansion areas north of Clyde River,
in the Malua Bay area as new subdivisions, and the remaining within existing developed
areas as infill.
The area also accommodates a large number of holiday/non-resident rate paying dwellings.
Whilst the holiday/non-resident rate paying dwellings are likely to remain an integral part of
this community, the numbers are likely to decline from their current level due to the owners
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Eurobodalla Integrated Water Cycle Management Strategy
moving to permanently live in them (i.e. retiring effect of baby boomers). Due to
development pressure, Council is investigating additional land areas that may be suitable
for urban subdivision. Although the timing of development of the various areas cannot be
predicted with certainty, it is accepted that the adopted population increase is sustainable.
Although Council’s current planning instruments allow for medium density and cluster
development, limits have been placed on building heights and population to floor space
ratio. To secure the built-up character of the future, Council is working with Planning NSW
to develop better and sustainable building envelopes and designs. Census figures show
that the age profile of the population spreads evenly between the age group 0–60 years.
Existing Water Management Systems
The Batemans Bay area is supplied by the regional water supply scheme, with Denhams
Beach service reservoir acting as the main storage. Denhams Beach supports a network of
local service reservoirs, the Long Beach reservoir services the area north of Clyde River,
the Batemans Bay and Catalina No. 2 reservoirs for the central area and the Lilli Pilli, Surf
Beach and Malua Bay reservoirs supply to the southern area.
A centralised sewage treatment plant located north west of Lilli Pilli services the whole
Batemans Bay area. The plant provides secondary treatment of the sewage and is based
on the continuous extended aeration process. The majority of the secondary treated
wastewater is returned to the environment through direct ocean discharge after natural
(pond) disinfection. Up to about 10% of the dry weather reclaimed water is reused on
Catalina Golf Club. The de-watered and stabilised biosolid is used for rehabilitating
Council’s landfill.
The sewer network servicing this area is extensive and has been grouped into three distinct
catchments:
!
The northern catchment serving the area north of Clyde River
!
The central catchment covering the central commercial areas, and
!
The southern catchment servicing the Lilli Pilli and Malua Bay areas (south of STP).
The northern catchment has about 10 pumping stations located along the bay foreshore
and conveys the sewage towards the treatment plant. The central catchment has about 30
pumping stations along the foreshore and a major station that receives the sewage
generated from both the local and north catchments. The sewage from the main pump
station is transferred direct to the treatment plant. The southern catchment also has about
10 pumping stations and a main station, which transfers the collected sewage to the
treatment plant.
The Eurobodalla Stormwater Management Plan has divided the area into 18 subcatchments (see Figure 9-6).
The sub-catchments to the north of Clyde River are predominantly residential. The runoff
from these catchments stems predominantly from house roofs, impervious driveways and
the road network. There are about 1.2 km of pipeline and 501 pits. The stormwater from
these sub-catchments north of the Clyde River drains to Cullendulla Creek and the ocean.
The land use of the seven central sub-catchments is mainly commercial and more than
80% of the area is impervious. There are about 4.83 km of stormwater pipeline and 1 576
pits. The stormwater from two of the sub-catchments drains to the ocean through Wimbie
Creek, Joes Creek and the other subcatchments drain directly to the ocean.
The land use of the six southern sub-catchments is predominantly residential. There are
about 1.13 km of pipeline and 35 pits. The stormwater from two of the sub-catchments
drains to a wetland, and the other sub-catchments drain directly to the ocean.
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Eurobodalla Integrated Water Cycle Management Strategy
Figure 9-6 Batemans Bay Stormwater Sub-Catchments
9.4.2
What Are the Issues?
The issues associated with the landscape and water management systems can be
classified into environmental, social and infrastructure performance, and these are
discussed below.
Environmental and Social Issues
!
Acid sulfate soils exposed from past and current development are impacting the
water quality of local creeks and waterways.
!
Raw sewage overflows from pumping stations enter estuaries during and following
prolonged power failure and during heavy local rainfall. These events have many
adverse affects including:
!
−
The impact on the ocean environment
−
The potential public health impact via the oyster industry and recreational
uses
−
The public inconvenience due to odour and visual impacts
−
The potential revenue loss to the oyster, recreational and hospitality
industries from beach closure and bad publicity.
Release of new areas for development is reducing the ‘natural’ appeal of the area
and is increasing rainfall runoff flows and velocity resulting in an increased
movement of sediment loads to the waterways.
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Eurobodalla Integrated Water Cycle Management Strategy
!
Water quality in Wimbie Creek is poor and odour complaints have been received
from residents living near the intermittently opening lagoon, which is supplied with
flows from Wimbie Creek.
!
In the absence of stormwater quality data the Short Beach Creek, Surf
Beach/Denhams Beach, North Batemans Bay, Surfside and Central Batemans Bay
sub-catchments have been identified, based on land use activity, as being
predominant contributors to litter problems and sediment loads in the surrounding
waterways.
!
Stormwater discharges from the Maloneys Beach, Long Beach, sub-catchments
have the potential to degrade wetlands protected under SEPP14 due to erosion and
the invasion of exotic weeds.
!
The low lying Lilli Pilli, Reedy Creek and Hanging Rock sub-catchments have the
potential to be impacted by catchment flooding and ocean inundation possibly
resulting in public inconvenience and public safety risk.
!
Wimbie Creek sub-catchment has been identified as a potential first priority urban
flooding area.
!
The central Batemans Bay sub-catchment and the Princes Highway (in particular
the bridge across Clyde River estuary) have been identified as a possible major
hydrocarbon pollution area.
Water Infrastructure Performance Issues
At the beginning of this study it was identified that there is a general lack of a systematic
database to record operational issues and daily performance monitoring information. Whilst
a simple data management system was put together for the purposes of this study, there is
a need to expand this data management system and gain a commitment from Council to
maintain its currency and historical information. Council is currently upgrading its telemetry
system to help address this issue.
Water Supply
As Batemans Bay is part of the regional water supply scheme, the water source and supply
issues have been discussed in the regional water supply scheme section (Section 8.2) and
as part of the IWCM opportunities and options. In this section of the strategy, only the
performance and issues relating to the local service reservoir and reticulation will be
discussed along with any specific local quantity, quality and service level issues.
The current and future peak day demands are shown in Table 9-9 Current and Future Peak
Day Demands for Batemans Bay. Analysis indicates that the existing local reservoir
capacity is able to meet Council’s service level for current demands, however it is
inadequate for future demands. Council advised that under current demand conditions the
area meets Council’s service level for mains pressure and fire fighting requirements. No
assessment has been undertaken to verify whether this is the case under the future
demand scenario.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-9 Current and Future Peak Day Demands for Batemans Bay
Current KL/d
2032 KL/d
1 224
2 242
758
919
Surf Beach
1 717
1 522
Catalina 2
9 750
12 377
406
523
13 855
17 583
Long Beach
Lilli Pilli
Batemans Bay
TOTAL
Sewerage
The Batemans Bay sewage treatment plant has a nominal biological capacity of 15 000 EP
(equivalent persons) but has been assessed to have the capability to treat double this
biological load with minor modification. This is due to past conservativeness in design and
improved process designs. However, the plant’s hydraulic capacity is inadequate to meet
current peak loads, particularly when it coincides with a storm event in peak holiday
periods. It is an accepted practice under these circumstances to by-pass secondary
treatment but not disinfection as the strength of the sewage is very weak. In addition to
requiring an upgrade due to inadequate hydraulic capacity, the STP also needs works to
meet current OH&S requirements.
In recent years there have been incidences of sewage overflows from the sewer network
particularly during and after power failure on rainy days. Investigations undertaken by
Council and as part of this study show that these overflows occurs due to a combination of
unreliable power supply to some critical pumping stations, inadequate coverage and
limitation on the existing telemetry system, high storm inflows and inadequate storm
storage capacity. Council has commenced a monitoring program of the pump stations to
determine those pump catchments suffering from inflow and infiltration. A preliminary
analysis of the data shows that the catchments prone to storm inflows include Denhams
Beach (SPS BB38) and Malua Bay (SPS BB44). Analysis also shows that a rainfall event
greater than approximately 6 mm will impact on sewage flows due to storm inflow.
A preliminary pumping and storage capacity analysis of the sewage transport system
indicated that there is inadequate storage capacity in most of the system under current load
conditions to comply with the agreed service levels. The analysis also indicated that the
major and oldest transfer main in the foreshores of central Batemans Bay is most at risk,
with inadequate transfer and storage capacity. Continued strong growth will exacerbate this
problem, potentially resulting in major sewage spills when a power failure coincides with a
peak load and rainfall event. Analysis has also indicated that not all pumping facilities are
controlled by the shire telemetry system and that some of the critical pumping facilities do
not have reliable external power supply and/or provision to connect to an emergency diesel
generator. Council’s operator indicated that pressurisation of the sewer pipeline between
Batehaven and Surf Beach is occurring and that some pump stations do not meet OH&S
requirements. Council has undertaken a comprehensive risk analysis to prioritise the
facilities needing immediate attention and is now in the process of undertaking a
comprehensive review of the transport network for capacity and storage.
The NSW Environment Protection Authority has indicated that there may be less than ideal
mixing of effluent at the current ocean discharge point, and that this may potentially lead to
an environmental health risk.
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Stormwater
In the absence of stormwater quantity and quality monitoring, preliminary estimates suggest
that the annual stormwater volume discharge from the urban area is 16 000 kL, with
nitrogen and phosphorus loads of 15 200 kg and 2 000 kg respectively.
A detailed analysis of each sub-catchment is contained in appendix W. Issues relating to
stormwater management and the infrastructure used for its management have been
identified, as follows:
9.4.3
!
Whilst most of the stormwater pipes have been recorded into the GIS, critical
information such as pipe size, age, slope, etc. is missing.
!
The GIS and the corresponding database does not include information on water
quality control measures that have been installed.
!
There is a general lack of urban stormwater quantity and quality information.
!
There is no formal approach to stormwater management that will result in better
management and efficient use of this resource.
!
Short Beach Creek sub-catchment floods during local rainfall events and requires
larger drainage pipes and/or source control measures, or greater maintenance to
reduce blockages.
!
There are no treatment measures in place to capture/remove hydrocarbon
pollutants from heavy traffic areas.
!
Soil erosion is evident at some discharge points.
!
Of all the sub-catchments in Batemans Bay, Short Beach, Surf Beach, Denhams
Beach, Joes Creek and Wimbie Creek sub-catchments have been identified as
requiring priority stormwater quantity and quality management measures.
!
Except for the regular removal of garbage from the public bins, there is no active
litter and sediment removal/collection program. There is however a gross pollutant
trap in the Batemans Bay Industrial Estate which discharges into Mcleods Creek
(SEPP 14).
How Do We Fix These Issues?
Overview
The landscape of the Batemans Bay area could be managed sustainably through the
implementation of appropriate planning controls. The issues of future development and acid
sulfate soil runoff could be managed by amending the local environmental and development
control plans.
There are a number of opportunities available to manage the water cycle of the Batemans
Bay area. The traditional approach to water management is to separate water, wastewater
and stormwater and treat each in isolation. In this strategy, all available opportunities have
been identified and coarse screened (see appendix C). The coarse screening process
recognises that there are immediate and short term measures, and medium to long term
water cycle management opportunities. The immediate and short term measures need to
be implemented as a matter of priority to achieve legislative compliance and best practice
standards. The shortlisted medium to long term water cycle management opportunities
would, in the long run, deliver water cycle sustainability, public health protection and
improved service standards.
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Eurobodalla Integrated Water Cycle Management Strategy
Immediate Measures
Investigations carried out by Council and as part of this study have identified the following
immediate measures, which include:
!
Improving the reliability of the grid power supply to the major sewage pump
stations. Council has already negotiated with the local power authority to provide
duplicate power supply from a different sub-station. Design work for this is currently
under way.
!
Providing stand-by local power supply using generators to some of the other critical
sewage pump stations where it is environmentally and socially acceptable. Council
has purchased a mobile generator to be used a sewage pump stations during
power failures. Tender documents are currently being prepared and Council is
awaiting State Government funding for construction.
!
Improving the reliability and coverage of monitoring and control of pump stations
using state-of-the-art telemetry system including maximising the use of existing
detention. Council has awarded tenders for the upgrade of the telemetry system,
and has gained financial assistance from the State government.
!
Developing a stormwater inflow and groundwater infiltration strategy for the
sewerage system - Council is currently monitoring a number of pump stations and
sub-catchments to identify, prioritise and develop management strategies for
problem areas. As part of the stormwater management program, Council is
allocating funds to purchase properties in flood prone areas. The proposed inflow
and infiltration strategy in addition to reviewing the current management programs
should also look at other ways to minimise flooding in those areas where purchase
in not possible. Examples include encouraging the implementation of measures
such as rainwater tanks with on-site detention volume, water sensitive urban design
principles or measures to increase the stormwater conveyance capacity.
!
Developing a dynamic model sewage collection and conveyance strategy for the
whole sewerage system including wet weather storage requirements. The dynamic
model is currently being developed and Council has received financial assistance
from the State Government.
!
Detention structures at most at risk downstream costal sewage pump stations.
Construction is to commence in 2003.
Most of the immediate measures are related to sewage collection and transport due to the
high risk impact posed by the uncontrolled overflow of untreated sewage in developed
areas. This poses a greater risk than the discharge of primary and/or secondary treated
effluent through the ocean outfall. Additional reasons include ease of implementation of
these measures at minimal cost with large environmental and social benefits and the
current high performance of the sewage treatment plant in achieving licence conditions.
Short term Measures
The short term measures include:
!
Relieving the current overload of current sewage pump stations by providing
bypass of North Batemans Bay flows by new sewage pump stations and rising main
along Spine Road alignment.
!
Expanding the simple data management system into a comprehensive shire-wide
system to record and store operational and performance monitoring information.
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Eurobodalla Integrated Water Cycle Management Strategy
!
Initiating regular and systematic monitoring of operational parameters such as daily
water use, sewage flows, water quality etc., and more strategic environmental and
social parameters.
!
Establishing a water supply reticulation network model to confirm pressure and
firefighting service standards.
!
Updating the asset registers to ensure the asset information is complete and up-todate.
!
Reviewing and updating the Batemans Bay stormwater management plan with
information and suggestions contained in this report.
Medium to Long term Water Cycle Management Opportunities
The medium to long term opportunities are related to enhancing the sustainability of the
water cycle, protecting public health and the environment and improving the service
standards.
Analysis suggests that even after the implementation of immediate measures, the sewage
management at Batemans Bay needs to be enhanced in the medium to long term due to
inadequate sewage treatment plant hydraulic capacity, and the close proximity of the main
sewer pipeline to the beaches.
Table 9-10 presents the water cycle management opportunities, their relative capital and
present value costs over a 30-year period at an annual discount rate of 7%. For details of
costs see appendix Q. Whilst the costs are indicative only, the relative cost difference
between the opportunities should be similar.
Table 9-10 Medium to Long term Water Cycle Management Opportunities for
Batemans Bay
Costs $m
Opportunity
Capital
NPV@7%
1.25
0.8
10
12.1
13.4
15.9
Transfer of southern catchment sewage load to Tomakin
1
STP
11.8
13.8
Stormwater quantity and quality control measures for
high priority sub-catchments
5.4
5.75
Stormwater quantity and quality control measures for low
priority sub-catchments
1.0
1.1
Local urban open space stormwater reuse
2.4
3
Provision of a new local reservoir
Enhance capability of existing sewage treatment plant
New sewage treatment plant in North Batemans Bay
1
1
Note 1: This cost indicates artificial UV treatment of the effluent. The quality could be further enhanced with sand
or membrane filtration and/or with wetland treatment.
Enhance the Biological and Hydraulic Capability of the Existing Sewage Treatment
Plant
Preliminary investigations suggest that the existing hydraulic capacity of the reactor and
clarifier at the STP is about 6.6 ML/d (27 500 EP) and this capacity could be enhanced by
the addition of chemicals to 9.2 ML/d (38 000 EP) provided the pipelines linking the various
treatment process units are adequate. However, at these high flows, the process safety
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Eurobodalla Integrated Water Cycle Management Strategy
margins are compromised and during wet weather flows plant by-pass will continue to
occur, albeit the frequency may be lower with the proposed inflow reduction management.
The by-pass of raw diluted sewage could be avoided by installing additional clarifiers to
settle the solids and provide some treatment. To reduce public health risk an artificial UV
irradiation plant could be installed at the outlet of the maturation pond, which could be used
to disinfect the effluent prior to discharge through the ocean outfall, and the reclaimed water
used at the golf club. The other works necessary for plant capacity augmentation include:
!
New inlet works
!
Minor process modifications
!
Additional aeration capacity and/or an aerated balancing storage at the inlet, and
!
Overall OH&S improvement for the plant.
An alternative to this process optimisation strategy is to build a parallel process train with
similar capacity to the current plant.
To overcome the incidence of sewage overflows from the coastal area, a dedicated pipeline
along Spine Road alignment could also be installed to convey sewage from the northern
catchment to the treatment plant.
A New Sewage Treatment Plant to Serve the North Batemans Bay Catchment
In this strategy, a new STP with an initial biological capacity of 5 000 EP would be built
north of Clyde River to treat all the sewage generated from the northern catchment. The
plant would be located on Council owned land. The reclaimed water from the plant would be
conveyed via the proposed Spine Road sewage main to the existing outfall. The advantage
of this strategy is the conveyance of reclaimed water across the Clyde River and up to the
existing plant as opposed to the conveyance of raw sewage. Another benefit may be the
reduction and/or elimination in the wet weather storage capacities within the existing sewer
network. In this strategy the existing STP would still need new inlet works and other minor
rehabilitation works to meet OH&S requirements. The reclaimed water discharged from
both STPs would be artificially disinfected using a common UV facility at the existing STP.
Transfer of Southern Catchment Sewage Load to Tomakin Sewage Treatment Plant
In this strategy, the sewage from the southern catchment would be transferred to the
existing Tomakin STP. Reversing the flow from the main southern pump station and
constructing a rising/gravity main to the Tomakin plant could achieve this. The benefit of
this strategy option is that the new rising/gravity main could be integrated with the proposed
rising/gravity main to serve the Rosedale and Guerilla Bay areas. Further, this opportunity
also maximises the utilisation of the currently under loaded Tomakin plant and discharges
the reclaimed water through a relatively better performing ocean outfall (verbal advice from
NSW EPA). In this opportunity the existing Batemans Bay plant would still require new inlet
works and other minor rehabilitation work to meet OH&S requirements. The reclaimed
water discharged from both STPs would be artificially disinfected using UV facilities located
at the respective STPs. The Tomakin plant would need minor upgrades to meet the
increased loads. Preliminary analysis shows that the performance of the plant could be
enhanced by optimising the treatment process and by dosing chemicals during periods of
peak holiday loads.
Assessment of Medium to Long term Water Cycle Management Opportunity
The TBL assessment in Table 9-11 provides the comparative environmental and social
benefits of the sewerage management component of the water cycle management
opportunities for Batemans Bay.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-11 Social, Financial and Environmental Aspects of the Sewage Management
Options for Batemans Bay
Issues Management Strategies
Social
Environmental
Financial
NPV ($m over
30 years)
Sewage Option 1 – Upgrade of the Surf Beach STP and sewer system
-
Transfer of sewage from North Batemans
Bay along Spine Road
-
Enhanced wet weather storage for priority
pump stations
-
Inflow and infiltration minimisation
-
Upgrade STP to a capacity of 38 000 EP
with improved wet weather treatment
Optimisation of
existing assets
12.1
Sewage Option 2 – New Plant in Northern Batemans Bay
-
Build a plant on the northern side of
Batemans Bay with a capacity of 5 000 EP
-
Transfer treated effluent to the Batemans
Bay outfall through a pipeline along Spine
Road
-
Inflow and infiltration minimisation
-
Enhanced wet weather storage for priority
pump stations
Disruption to
local residents.
Possible
opposition to
new treatment
plant
Transfer of effluent
only from Northern
Batemans Bay to
outfall. Possibility of
reuse at growth
areas
15.9
Sewage Option 3 -- Transfer of Southern Catchment to Tomakin Plant
136
-
Transfer of sewage from North Batemans
Bay along Spine Road
-
Inflow and infiltration minimisation
-
Enhanced wet weather storage for priority
pump stations
-
Transfer of sewage from Malua Bay area
through a new rising/gravity main to
Tomakin plant
-
Optimise Tomakin STP to cater for the
Maula Bay load in addition to future local
growth requirement
Use of better outfall
Optimisation of
existing assets
More reuse
possibilities at
Tomakin than
Batemans Bay
13.8
Eurobodalla Integrated Water Cycle Management Strategy
Table 9-12 Triple Bottom Line Assessment of the Sewage Management of the Water
Cycle in Batemans Bay
Option 1
Option 2
Option 3
Efficient use of fresh water resource
1
2
3
Minimises low flow water extractions
1
2
3
Minimises greenhouse gas emissions
1
2
2
Minimises pollutants being discharged to
the aquatic environment
2
2
2
Minimises urban stormwater volumes
0
0
0
Ensures sustainable practices
1
2
3
Environmental Sum
6
10
13
Environmental Rank
3
2
1
Improves security of town water supply
1
2
3
Improves the quality of drinking water
0
0
0
Improves urban water service levels
2
2
2
Increases public awareness of urban
water issues
1
2
3
Minimises non-compliance to policy and
legislation
2
2
2
Protects public health
0
0
0
Social Sum
6
8
10
Social Rank
3
2
1
12.1
15.9
13.8
Financial Rank
1
3
2
TBL SUM
7
7
4
TBL Rank
2
2
1
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV ($m over next 30 years)
A TBL assessment has been used to shortlist the most suitable sewage treatment option
available for Batemans Bay. Using the above social, environmental and economic criteria,
option 3 has been determined as the most appropriate option, and has been carried
through as part of the integrated options.
9.4.4
Integrated Water Cycle Management Scenarios
Using the bundling process the water management opportunities can be combined into
integrated scenarios. Table 9-13 below presents examples of integrated scenarios.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-13 Integrated Water Cycle Management Scenarios for Batemans Bay
Managed Option
Traditional
Approach
Integrated Scenario
2
3
Provision of a new local reservoir
"
Transfer of sewage from northern
catchment via Spine Road alignment
"
"
"
Transfer of southern catchment sewage
load to Tomakin STP
"
"
"
"
"
Stormwater quantity and quality control
measures for high priority sub-catchments
Stormwater quantity and quality control
measures for low priority sub-catchments
Local urban open space stormwater and
reclaimed water use
"
"
"
Traditional Approach Provide a new local reservoir, and transfer of southern catchment sewage
load to Tomakin STP.
Integrated Scenario 2 Transfer of southern catchment sewage load to Tomakin STP, implement
stormwater quantity and quality control measures for high priority sub-catchments and incorporate
local urban open space stormwater reuse.
Integrated Scenario 3 Transfer of southern catchment sewage load to Tomakin STP, implement
stormwater quantity and quality control measures for high and low priority sub-catchments and
incorporate local urban open space stormwater and reclaimed water use.
The TBL assessment (Table 9-14) presents the comparative social and environmental
benefits of each integrated scenario example.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-14 Triple Bottom Line Reporting for Batemans Bay
Traditional
Approach
2
3
Efficient use of fresh water resource
1
2
2
Minimises low flow water extractions
1
2
2
Minimises greenhouse gas emissions
3
3
3
Minimises pollutants being discharged to
the aquatic environment
0
2
3
Minimises urban stormwater volumes
0
2
3
Ensures sustainable practices
0
3
3
Environmental Sum
5
14
16
Environmental Rank
3
2
1
Improves security of town water supply
1
2
2
Improves the quality of drinking water
0
0
0
Improves urban water service levels
3
3
3
Increases public awareness of urban
water issues
0
3
3
Minimises non-compliance to policy and
legislation
2
2
2
Protects public health
2
2
3
Social Sum
8
12
13
Social Rank
3
2
1
14.6
22.6
23.6
Financial Rank
1
2
3
TBL SUM
7
6
5
TBL Rank
3
2
1
Outcomes
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV ($m over next 30 years)
According to the TBL assessment, scenario 3 is the most suitable option in terms of
environmental, social and economic criteria. This option involves transferring sewage loads
from the southern catchment to Tomakin STP, and quantity and quality control of
stormwater in both high and low priority catchments. This scenario also incorporates open
space stormwater and reclaimed water use
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Eurobodalla Integrated Water Cycle Management Strategy
9.5
9.5.1
Mogo
Background
The Village Landscape
Mogo is an historic village located on the Princes Highway between Batemans Bay and
Moruya (see Figure 9-7 below).
Figure 9-7 Mogo Topographic Map
The 2001 census recorded 223 people in Mogo and 110 dwellings. The 1996 housing
monitor stated there were 56 vacant lots in Mogo, with an annual demand of 3 lots. This
analysis indicates that there will be a land shortage in the village by 2015. However,
comparison of the 1996 and 2001 census shows that the number of private dwellings and
the population in the collection district did not change significantly between the two census.
Therefore, the water demands from residential properties have been assumed not to
increase over time. It is assumed that commercial properties will increase at a rate
comparable with the overall population growth.
Existing Water Management Systems
The town is fed by the Mogo reservoir through the supply scheme. The reservoir has
sufficient capacity to cope with the expected 2032 peak day demand of 510 kL/d. The
sewage from the village is treated at the Tomakin STP.
According to the GIS, there are 36 stormwater pits and 4.7 km of pipeline in Mogo. Due to
the town population being less than 1 000 there is no requirement for a stormwater
management plan. Stormwater drains to McLeods and Mogo creeks. An annual estimated
948 kL/a of stormwater is generated in Mogo containing 1 137kg/a of nitrogen and 152kg/a
of phosphorus.
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Eurobodalla Integrated Water Cycle Management Strategy
9.5.2
What Are the Issues?
The issues associated with Mogo landscape and water management system are classified
into environmental and social issues, and are discussed below. Other community servicerelated issues are not in included as part of this study.
Environmental Issues
!
Potential stormwater hotspot pollution sites include the zoo and tourism sources
!
Potential sewage overflow from stormwater influx to sewage pumping station.
Social Issues
9.5.3
!
Maintain the character and lifestyle of the village
!
Tourism is main income for village
!
Stormwater-derived pollution has the potential to reduce recreational and tourism
attractions
!
Problems maintaining a chlorine residual in the water system.
How Do We Fix the Problems?
Water Cycle Management Opportunities
The following are short term measures to improve the water cycle management at Mogo.
Short term Measures
The short term measures include:
!
Improve chlorine residual
!
Systematic monitoring of the local waterways and the urban stormwater quality and
quantity.
The long term water management issues are addressed as part of the regional water
supply scheme and sewage and wastewater management issues in the Tomakin section of
the report.
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Eurobodalla Integrated Water Cycle Management Strategy
9.6
9.6.1
Rosedale and Guerilla Bay
Background
The Village Landscape
Rosedale and Guerilla Bay are two coastal villages located between Batemans Bay and
Tomakin. Development in Rosedale (the most northerly of the two villages) has been
concentrated along Rosedale Beach and Saltwater Creek, while Guerilla Bay has an urban
development corridor stretching in a west-east direction along Burri Point Road. There are
two intermittently opening and closing lagoons near the villages. Access to both villages is
from George Bass Drive. Figure 9-8 shows the location of these two coastal villages.
Figure 9-8 Rosedale and Guerilla Bay Location
The two villages are bordered by the Pacific Ocean to the east but have the potential for
urban expansion towards the north and west. Adjacent to the two villages are sensitive
coastal lagoons which are popular for recreational activities. The 2001 census recorded 197
people in Rosedale/Guerilla Bay, and 272 dwellings. There is an Urban Expansion Zone
located inland of the current development. There are between 1 100 and 1 200 lots
allocated for development in this area which are expected to be fully developed in the next
10 years.
Existing Water Management Systems
The towns are supplied with water through the regional supply scheme discussed earlier.
The annual water demands are approximately 560 kL/d. The villages are supplied through
the Burri Point Reservoir, which has sufficient capacity to cope with the predicted demand
until 2032.
The sewage from the villages is currently treated on site. The Council’s GIS records 272
individual on-site treatment systems in the villages. Over 65% of these are septic tanks with
wastewater disposal by adsorption trench, and an additional 18% are septic tanks with
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Eurobodalla Integrated Water Cycle Management Strategy
wastewater pumpout. The remaining systems utilise aerated processes that give higher
levels of nutrient removal than septic systems.
Figure 9-9 Aerial Photograph of Rosedale and Guerilla Bay Showing Their Proximity
to Tomakin and Mossy Point
9.6.2
What Are The Issues
The issues associated with the Rosedale and Guerilla Bay landscape and water
management system are classified into environmental and social issues, and are discussed
below. Other community services-related issues are not part of this study.
Environmental Issues
!
The soils in the Guerilla Bay and Rosedale area are generally unsuitable for
controlled absorption (soils range from sandy, hard gravel and clay). It is therefore
commonly acknowledged that sewage/wastewater from on-site wastewater
management systems will infiltrate into the groundwater aquifer and ultimately end
up in the waterways. This could be particularly detrimental due to the presence of
two sensitive lagoons in the area.
!
Stormwater entering the lagoon from the developed areas has the potential to
impact upon the health and visual quality of the lagoon. The likely pollutants are
hydrocarbons from the roads, litter particularly from the identified hot spots (e.g.
carparks) nutrients and particles associated with the sediments. In the absence of
stormwater quantity and quality monitoring, preliminary estimates suggest an
annual nutrient load of 795 kL with nitrogen and phosphorus loads of 1 000 kg and
100 kg respectively.
!
The two intermittently opening lagoons can become odorous when closed. This
may be due to the decomposition of seaweed washed in during high storms or
pollution from the urban areas.
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Eurobodalla Integrated Water Cycle Management Strategy
Social Issues
9.6.3
!
The wastewater from the on-site systems poses a risk to public health, with
recorded incidents of overflow into streets.
!
Of the unsewered villages in Eurobodalla Shire, Rosedale and Guerilla Bay have
the highest population with increased public health risk.
!
The village residents do not receive water saving ‘tips’ or information on how to
better manage the on-site wastewater management systems.
!
An urban expansion zone is currently under development inland of the existing
villages.
How Do We Fix The Problems
Overview
The WSUD principles as discussed in Section 8.1.3, could be implemented in Rosedale
and Guerilla Bay to design new developments in an integrated fashion to reduce their
impacts on the environment. Elements of WUSD include:
!
Reduced mains water consumption through the use of water-efficient devices and
rainwater tanks
!
Reduced stormwater flow by on-site detention measures, and
!
Improvements in stormwater quality through natural treatment processes such as
wetlands.
It is recommended that these features be incorporated as part of the planning for the new
development area.
The current sewage management practices are not sustainable due to the significant
impact on the groundwater and the potential to pollute the two nearby lagoons. The majority
of the dwellings in the area use septic systems with adsorption trenches, which are not
suitable for the sandy, gravel and clay soils of the region. Rosedale and Guerilla Bay ranked
the highest priority for management intervention on a risk analysis conducted on most of
the small villages in the Eurobodalla Shire (see appendix X for the assessment criteria).
It is recommended that Council take over the provision of sewage treatment for the villages
as a matter of priority. This could be done through the centralised management of on-site
systems or provision of a centralised treatment facility.
Water Cycle Management Opportunities
There are both short and medium term measures to improve the water cycle management
at Rosedale and Guerilla Bay. The short term measures should be implemented as a
matter of priority to achieve best practice standard immaterial of the medium-term
opportunities.
Short term Measures
The short term measures include:
!
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Regular monitoring of the on-site wastewater management systems for
performance and integrity
Eurobodalla Integrated Water Cycle Management Strategy
!
Systematic monitoring of local waterways and urban stormwater quality and
quantity
!
Regular mail-outs of ways to maintain the on-site water and wastewater systems
including information on water conservation
!
The above short term measures are complimentary to the proposed medium-term
measures and would help Council and the community to manage their water cycle
more sustainably.
Medium to Long term Water Cycle Management Opportunities
Medium-term opportunities are measures related to improving the long term sustainability
of the water cycle. In addition, these opportunities will also reduce public health and
environmental impacts and enhance the service standards for the water services. Table
9-15 presents these opportunities along with their capital and present value at an annual
discount rate of 7%.
Table 9-15 Integrated Water Cycle Management Opportunities for Rosedale and
Guerilla Bay
Cost Estimate
Capital ($m)
NPV @ 7% ($m)
Improved management of existing on-site facilities
$0.41
$2.24
Enhanced management of existing on-site
facilities
$1.31
$1.74
Centralised
management of
effluent from on-site
facilities
Transfer to Tomakin
system
$2.85
$2.43
Transfer to Tomakin
system
$3.06
$2.73
Transfer to Tomakin
system with greywater
reuse of suitable systems
$3.06
$2.73
Transfer to Tomakin
system with greywater
reuse of suitable systems
and roofwater harvesting
utilising disinfected tanks
$3.06
$2.73
Provision of full
reticulated
sewerage system
Note 1: NPV’s for on-site systems are based on a rolling program commencing in 2003. NPV’s for sewering
Rosedale and Guerilla Bay are based on work commencing in 2006
Note 2: The savings achieved by Council treating less effluent have not been taken take into account in the study
and the costs associated with greywater reuse are community costs
Improved Management of Existing On-site Wastewater Facilities
The seepage from existing on-site wastewater management systems could be reduced by
regularly emptying the contents of the septic tanks and putting monitoring systems in place
to prevent septic tank overflows and to assess the integrity of the tanks.
A single contract could be arranged by the Council or by the community such that the septic
tanks are pumped at set time intervals. This would cover both wastewater and sullage
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Eurobodalla Integrated Water Cycle Management Strategy
pumpout. The cost of this pumpout could be evenly divided between the residents. To
facilitate pumping every tank would require a smaller holding tank or pumpout facility.
This opportunity would reduce the issue of wastewater contaminating the local aquifers and
waterways, but may lead to additional community issues in relation to odour and noise
during pumpout and frequent movement of trucks in the neighbourhood.
Enhanced Management of Existing On-site Wastewater Facilities
There are several options available to upgrade the existing on-site wastewater
management systems to achieve greater public health and environmental outcomes. The
first option is to retain the existing septic tank and upgrade the on-site wastewater
management system. An example of this would be the replacement of the adsorption
trenches with lined evapotranspiration beds, which achieve a higher level of water and
nutrient uptake through plants.
Another alternative is to upgrade the septic system to one that achieves nutrient removal
(e.g. aerated tanks) and therefore results in a higher quality wastewater discharge. This
would increase the potential uses of the treated wastewater.
The enhanced management of the current on-site systems would minimise the potential
risk of pollution contaminating the lagoons and waterways as well as reducing the likelihood
of public health issues and odour complaints.
Centralised Management of Effluent from On-site Facilities
As an alternative to providing a full reticulated sewage system, the wastewater from existing
on-site systems (e.g. septic tanks) could be collected and transported to a central treatment
facility. This type of system relies on smaller pipes than those required for a conventional
reticulated sewerage system. Pipes can be laid in the ground at a lesser gradient and at a
more shallow depth than that of a conventional gravity system, as the solids are captured by
the on-site system and the pipes only need to carry liquid wastewater. The wastewater
would be transported to Tomakin STP for treatment.
Provision of Full Reticulated Sewerage System
An alternative to on-site sewerage treatment facilities is to transfer wastewater through a
centralised sewer transport network to Tomakin STP. This opportunity would require the
provision of larger pipes than for the previous option, which would possibly require being
installed at greater depths.
Provision of Full Reticulated Sewerage System with Grey Water Reuse
On-site systems that achieve a suitable level of treatment for greywater would be
maintained, and blackwater only would be transported to the STP using the reticulation
systems described above. The resulting greywater could then be utilised for a variety of
outdoor uses and for toilet flushing. Maintaining current aerated systems in Rosedale and
Guerilla Bay for greywater reuse would reduce the volume of wastewater requiring
treatment by 4 ML/a. In addition to reducing the volume of imported or reticulated water
required for Rosedale and Guerilla Bay, this would reduce the hydraulic load on the
Tomakin STP. With the implementation of appropriate monitoring systems, long term
environmental and water resource sustainability and public health protection could be
achieved.
Provision of Full Reticulated Sewerage System with Grey Water Reuse and Roofwater
Harvesting
This opportunity incorporates components of the previous opportunity. Systems that are not
suitable for greywater reuse (e.g. septic tanks) would be de-sludged and disinfected and
used to collect roofwater for non-potable uses including garden watering and toilet flushing.
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Eurobodalla Integrated Water Cycle Management Strategy
This would result in an additional 9.32 ML/a of wastewater not requiring transportation and
treatment at the Tomakin STP. Together with greywater reuse from aerated systems, a
total of 13.32 ML/a could be saved.
Social and Environmental Aspects of Medium to Long term Water Cycle Management
Opportunities
The TBL assessment in Table 9-16 provides the comparative environmental and social
benefits of each of the water cycle management opportunities.
Table 9-16 Social and Environmental Aspects of the Medium to Long term
Opportunities for Rosedale and Guerilla Bay
Opportunities
Social
Associated odour and noise
impacts
Improved management of existing onsite facilities
Inconvenience of pumpout
trucks in the area
Reduces likelihood of overflows
from on-site systems
Environmental
Improves environmental
outcomes, minimises the
incidence of septic wastewater
contaminating groundwater and
waterways
Improves air quality and visual
character
Enhanced management of existing onsite facilities
Enhances aesthetic appeal for
the local area, good for tourism
and recreational activities
Reduces impact to local aquifers
and the environment
Reduces likelihood of overflows
from on-site systems
Limited additional treatment
infrastructure required
Centralised
management of
effluent from onsite facilities
Existing resources can be
utilised
Transfer to
Tomakin system
Short term inconvenience for
residents during construction,
i.e. noise, vehicle movement
Possible environmental impact
during construction
Less overall environmental
impacts than conventional
gravity systems
May allow for regional reuse
Improves air quality and visual
character
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Eurobodalla Integrated Water Cycle Management Strategy
Opportunities
Social
Environmental
Improves quality of effluent
discharged to environment
Limited additional treatment
infrastructure required
Existing resources can be
utilised
Transfer to
Tomakin system
Short term inconvenience for
residents during construction,
i.e. noise, vehicle movement
Improves air quality and visual
character
Limited additional infrastructure
required
Existing resources can be
utilised
Provision of full
reticulated
sewerage system
Transfer to
Tomakin system
with greywater
reuse of suitable
systems
Improves air quality and visual
character
Short term inconvenience for
residents during construction,
i.e. noise, vehicle movement
Reduces water demands
Decreases hydraulic and
biological loads on the Tomakin
system
Limited additional infrastructure
required
Transfer to
Tomakin system
with greywater
reuse of suitable
systems and
roofwater
harvesting
utilising
disinfected tanks
Possible environmental impact
during construction
Significantly reduces likelihood
of groundwater and waterway
contamination
More efficient use of water
resources, may allow for
regional reuse
Improves quality of effluent
discharged to environment
Increases opportunities for
effluent reuse
Possible environmental impact
during construction
Significantly reduces likelihood
of groundwater and waterway
contamination
More efficient use of water
resources
Improved quality of effluent
discharged to environment
Use of existing resources
Improved air quality and visual
character
Short term inconvenience for
residents during construction i.e.
noise, vehicle movement
Further reduced water demands
Decreased hydraulic and
biological loads on the Tomakin
system
148
Increases opportunities for
effluent reuse
Increased opportunities for
effluent reuse
Possible environmental impact
during construction
Significantly reduced likelihood
of groundwater and waterway
contamination
Maximum use of water
resources
Eurobodalla Integrated Water Cycle Management Strategy
9.6.4
Integrated Water Cycle Management Scenarios for Rosedale and
Guerilla Bay
Table 9-17Integrated Water Cycle Management Scenarios for Rosedale and Guerilla
Bay
Minimal
Improved management of existing onsite facilities
Traditional
Approach
3
Provision of
full reticulated
sewerage
system
6
"
Transfer to Tomakin
system
Transfer to Tomakin
system
5
"
Enhanced management of existing onsite facilities
Centralised
management
of effluent
from on-site
facilities
4
"
"
Transfer to Tomakin
system with
greywater reuse of
suitable systems
Transfer to Tomakin
system with
greywater reuse of
suitable systems
and roofwater
harvesting utilising
disinfected tanks
"
"
Minimal Improved management of existing on-site facilities.
Traditional Provision of full reticulated water systems from the regional supply, and the provision of
full reticulated sewerage systems with transfer to the Tomakin system.
Integrated Scenario 3 Centralised management of effluent from on-site facilities with transfer to the
Tomakin system.
Integrated Scenario 4 Enhanced management of existing on-site facilities.
Integrated Scenario 5 Provision of full reticulated sewerage with transfer to the Tomakin system
and greywater reuse.
Integrated Scenario 6 Provision of full reticulated sewerage with transfer to Tomakin system with
greywater reuse of suitable systems and roofwater harvesting utilising disinfected tanks.
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9.6.5
Triple Bottom Line Assessment for Rosedale and Guerilla Bay
Table 9-18 Triple Bottom Line Assessment for Rosedale and Guerilla Bay
Minimal
Traditional
Approach
3
4
5
6
Efficient use of fresh water
resource
1
0
1
0
1
2
Minimises low flow water
extractions
0
0
1
0
2
2
Minimises greenhouse gas
emissions
1
1
1
2
2
2
Minimises pollutants being
discharged to the aquatic
environment
2
2
2
1
2
2
Minimises urban stormwater
volumes
0
0
0
0
0
2
Ensures sustainable land
use practices
0
1
1
1
2
2
Environmental Sum
4
4
6
4
9
12
Environmental Rank
4
4
3
4
2
1
Improves security of town
water supply
0
0
0
0
2
2
Improves the quality of
drinking water
0
0
0
0
0
0
Improves urban water
service levels
1
3
3
3
3
3
Increases public awareness
of urban water issues
3
1
1
2
2
2
Minimises non-compliance
to policy and legislation
1
3
3
3
3
3
Protects public health
1
3
3
3
3
3
Social Sum
6
10
10
11
13
13
Social Rank
6
4
4
3
1
1
2.24
3.06
2.45
1.74
3.06
3.06
Financial Rank
3
4
2
1
4
4
TBL Score
13
12
9
8
7
6
TBL Rank
6
5
4
3
2
1
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV ($m over 30 years)
According to the TBL assessment criteria, the best option is to transfer sewage to Tomakin,
with the on-site systems retained for greywater treatment or roof water harvesting as
appropriate. Although the cost of this option does not vary significantly from the other
integrated scenarios, it performs best overall against the social and environmental criteria
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9.7
9.7.1
Tomakin and Surrounds
Background
The Landscape
Tomakin and the surrounds comprises the urban areas of Tomakin, Mossy Point and
Broulee. These three urban areas are located along the foreshores of Broulee Bay. Mossy
Point lies in the central area and is bounded by Candlagan Creek to the south and the
Tomaga River to the north. The upper tidal reaches of the Tomaga River support several
oyster farms. Around Mossy Point several sensitive wetlands can be found. Figure 9-10
shows the location of Tomakin and surrounding areas.
Figure 9-10 Tomakin Topographic Map
The 2001 census recorded 2 388 people in the area and 2 100 dwellings. Council has
identified that the population growth in this area will be accommodated within the zoned
urban expansion areas near Tomakin as new subdivision and the remaining within existing
developed areas. Due to development pressures, Council has also nominated additional
land areas west of Tomakin that may be suitable for urban subdivision. Although the timing
of development of the various areas cannot be predicted with certainty, it is accepted that
the predicted population increase is sustainable. This area also supports a significant tourist
population, with the population increasing to about 1 600 during the peak holiday season.
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Eurobodalla Integrated Water Cycle Management Strategy
Existing Water Management System
The area is supplied by the regional water supply scheme, which fills three local service
reservoirs, Tomakin Heights for the small number of houses in Barlings Drive, Burri Point
Reservoir for Rosedale, Guerilla Bay and Tomakin, and Mossy Point for the Mossy Point
and Broulee areas. The Tomakin Heights reservoirs have a combined capacity of 0.2 ML.
The capacity of Mossy Point reservoirs is 4.6 ML and Burri Point is 5.0 ML. Current and
future average and peak day demands are shown in Table 9-19.
During the 1982/83 drought, bores were sunk along Broulee Road, South of Broulee to
provide drought security for the regional scheme. . These bores were used for three months
until the end of the 1983 drought and were subsequently capped.
Recent water quality testing of these bores indicated elevated arsenic iron and nitrate
levels, which may be in part from the past poor management of septic tanks. This has
raised serious doubts over the long term sustainability of these bores Many of the Broulee
residents to date use bore water from their backyard bore, predominantly to water their
gardens.
Table 9-19 Current and Future Average and Peak Day Demands for Tomakin
Current
2032
ADD kL/d
PDD kL/d
ADD kL/d
PDD kL/d
Mossy Point
814
1 791
748
1 646
Burri Point
560
1 233
1 299
2 858
Tomakin Heights
21
46
18
41
TOTAL
835
1 837
766
1 687
A centralised sewage treatment plant located north-east of Tomakin services the three
urban centres and the village of Mogo. The STP provides secondary treatment and is
based on the continuous extended aeration process. After natural disinfection the majority
of the secondary treated water is returned to the environment through direct ocean
discharge. The de-watered and stabilised biosolid is used for rehabilitating Council’s landfill.
There are five stormwater sub-catchments within Tomakin, which include Barlings Beach,
Tomakin, Mossy Point North, Candlagan Creek and South Broulee. The land use within
these areas is primarily residential. Figure 9-11 shows the location of these subcatchments.
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Eurobodalla Integrated Water Cycle Management Strategy
Figure 9-11 Tomakin Stormwater Sub-Catchments
9.7.2
What Are the Issues?
The issues associated with the landscape and water management systems can be
classified into environmental, social and water infrastructure performance. These issues are
discussed below.
Environmental and Social Issues
!
Possible public concern with regard to insufficient disinfection of effluent during
peak load and/or wet periods.
!
Possible sewage overflows from the sewer network as the system ages and loads
increase leading to a greater environmental problems and health risks for the local
community.
!
Odour at the inlet works of the STP resulting in customer complaints. Pressure
from developers to reduce the size of the STP buffer zones will only exacerbate this
issue.
!
High water tables in the area leave the community exposed to possible flooding.
!
Urban water flooding occurs frequently in Candlagan Creek and South Broulee.
!
Discharge of stormwater into vulnerable ecosystems and wetlands. If unabated, the
impact will become significant when new development commences adjacent to
environmentally sensitive areas.
!
Historical water quality tests show that the aquifer around Broulee is of poor quality
due to old septic tank systems.
!
Present groundwater extraction volumes may be unsustainable.
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Eurobodalla Integrated Water Cycle Management Strategy
!
There is a need to sustainably manage the use of the Broulee aquifer for continued
use by both the environment and the water users.
Water Infrastructure Performance Issues
Water Supply
Analysis indicates that the existing local reservoir capacity meets Council’s service level for
current and future demands. Council has advised that under current demand conditions the
system also meets Council’s service level for mains pressure and fire fighting requirements.
Some residents use groundwater for garden watering. Based on past water quality data, the
practice poses a minor risk to the users however over-use of this resource poses a threat to
the environment. Measures should be taken to ensure this source is sustainably managed
for continued use by the environment and the householders.
Sewage
The nominal design capacity of the plant will be exceeded by around 2015, however the
reactor and the clarifier has been assessed to have a treatment capability in excess of
3.7 ML/d or 15 000 EP. This means the plant has the capacity to process loads for the next
30+ years, provided the pipeline linking the various treatment process units is adequate.
However, the plant needs some rehabilitation works to meet current OH&S legislation.
It is important to note that if the option to transfer sewage from the southern catchment of
Batemans Bay to Tomakin STP is implemented, the Tomakin STP would require increased
capacity to be implemented in 2-3 years time, rather than 15 years as indicated earlier.
The sewer network servicing Tomakin and the surrounding area is extensive and has been
grouped into three distinct catchments, the southern catchment serving the Broulee area,
the central catchment covering the Mossy Point area, and the northern catchment covering
the Tomakin area. There are six pumping stations in Broulee located along the bay
foreshore that transfer the sewage towards the treatment plant. There are three pumping
stations in Mossy Point and a major station that receives the sewage generated from both
the local and Broulee catchments. The sewage from the main pump station is transferred to
a main pumping station in the Tomakin catchment, which together with the local flows
transfers the sewage to the STP.
Due to its relative recent construction and the lower than anticipated load, the sewer
network has been performing satisfactorily during and after power failure and during rainy
periods. Due to the long transport network, high levels of hydrogen sulfide are generated
causing odours and impacting on the life of the assets. In view of the proximity of the main
transport link to the surrounding beaches, it is suggested Council undertake a
comprehensive risk analysis to identify potential failure modes and the critical facilities in
the network system. This analysis could then be used to develop critical control and
management response plans.
Although the EPA has assessed the performance of the outfall as being among the best in
NSW, in order to meet best practice standards Council should consider disinfecting the
wastewater prior to its discharge to the ocean environment. This, in addition to meeting best
practice standards, would also provide increased public health protection and improve the
aesthetic and environmental appeal of the area. Similar to the Batemans Bay system,
options available to enhance the discharge quality include wetland treatment, air flotation
and sand or membrane filtration. Reclaimed water reuse and recycling strategies are
discussed in Section 3.
Stormwater
The Barlings Beach sub-catchment encompasses vulnerable ecosystems and a significant
wetland that will need protection when development occurs. The main road that leads into
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Eurobodalla Integrated Water Cycle Management Strategy
the residential areas requires some structural solutions to improve water quality. An
estimated 7.92 ML/a of stormwater is generated in Tomakin and the surrounding area
annually, containing 7 400 kg/a of nitrogen and 1 000 kg/a of phosphorus. Candlagan Creek
is a priority catchment for stormwater management.
9.7.3
How Do We Fix these Issues?
Overview
The landscape of the Tomakin region could be managed sustainably through the
implementation of the appropriate planning controls. The issues of future development and
acid sulfate soil runoff could be managed by amending the local environmental plan and
development control plans.
There are a number of opportunities to manage the water cycle of Tomakin and the
surrounding natural and urban landscapes. The opportunities available for stormwater,
wastewater and water supply were traditionally examined individually. In this strategy, all
available opportunities have been identified and coarse screened (see Appendix C). The
coarse screening process recognises that there are immediate and short term measures,
and medium to long term water cycle management opportunities. The immediate and short
term measures need to be implemented as a matter of priority to achieve legislative
compliance and best practice standards. The short-listed medium to long term water cycle
management opportunities would in the long run deliver water cycle sustainability, public
health protection and improved service standards.
Immediate Measures
Investigations carried out by Council and as part of this study have identified the following
immediate measures, which include:
!
A risk assessment of the sewerage system to identify critical facilities and to
develop mitigative measures and critical control and response management plans.
!
Developing a storm water inflow and groundwater infiltration strategy.
Short term Measures
The short term measures include:
!
Expanding the simple data management system into a comprehensive Shire wide
system to record and store operational and performance monitoring information.
!
Initiating regular and systematic monitoring of the operational parameters such as
daily water use, sewage flows, water quality etc and more strategic environmental
and social parameters.
!
Establishing a water supply reticulation network model to confirm pressure and
firefighting service standards.
!
Updating the asset registers to ensure the asset information is complete and up to
date.
!
Addition of a UV treatment plant for disinfecting the reclaimed water.
!
Odour and hydrogen sulfide control.
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Eurobodalla Integrated Water Cycle Management Strategy
Medium to Long Term Water Cycle Management Opportunities
The medium to long term opportunities are related to enhancing the sustainability of the
water cycle, protecting the public health and environment and improving the service
standards.
As part of a long term strategy, the water quality and quantity of the Broulee aquifer needs
to be managed so that the environment and current water users can continue to enjoy this
resource in a sustainable manner. Options include:
!
Reduce or ration the volume of water extracted from the aquifer.
!
Inject and store highly treated reclaimed water from the Tomakin STP into the
aquifer such that a balance is maintained between extraction and injection. If more
local users take-up this option within sustainability limits, it has the potential to
reduce demand on the regional water supply scheme and increase the secure yield
of the regional supply infrastructure.
Mossy Point and Broulee areas receive town water supplied through the regional water
supply scheme. Water is supplied through the 4.6 ML Mossy Point Reservoir. There is
sufficient capacity for all future growth. Some residents in Broulee use groundwater for nonpotable external use.
Table 9-20 Costing of Management Opportunities presents the water cycle management
opportunities, their relative capital and present value costs over a 30-year period at an
annual discount rate of 7%. Whilst the costs are indicative only, the relative cost difference
between the opportunities should be similar.
Table 9-20 Costing of Management Opportunities in Tomakin and Surrounds
Costs ($)
Opportunity
Capital
NPV @ 7%
Process optimisation strategy
1.7 M
1.64 M
Construct a parallel process train
2.85 M
2.3 M
Stormwater quantity and quality control measures for
high priority sub-catchments
1.72
1.8
Stormwater quantity and quality control measures for low
priority sub-catchments
0.5
0.53
Enhance
capability of
existing STP
1
Enhance the Biological and Hydraulic Capability of the Existing Tomakin Sewage
Treatment Plant
The Tomakin STP has a nominal biological capacity of 8 000 EP however the reactor and
clarifier has been assessed to have a treatment capacity able to process double this
biological load (3.7 ML/d or 15 000 EP) with minor modification. This is due to past
conservativeness in design and improved design techniques. The biological treatment
capacity of the reactor and clarifier could be further increased to about 4.9 ML/d
(20 000 EP) by the addition of chemicals provided the pipeline linking the various treatment
process units are adequate. It is an accepted practice under these circumstances to bypass the secondary treatment, and only apply disinfection, as the strength of the sewage is
very weak.
An alternate to the process optimisation strategy is the traditional strategy including a
parallel process train with similar capacity to the current plant is built.
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Eurobodalla Integrated Water Cycle Management Strategy
Reclaimed Water Reuse
Wastewater can be treated to a suitable level for a variety of beneficial reuse. These
include industrial, agricultural, open space irrigation, non-potable domestic reuse and
indirect potable reuse. The opportunity exists in Tomakin and Surrounds to utilise effluent
reuse for open space irrigation, for dual reticulation in new developments or could form part
of the regional reuse scheme.
Stormwater Quality and Quantity Control measures
Stormwater can be collected and stored, and then treated for release at a controlled rate.
The temporary storage of flood waters will have the effect of attenuating the peak flow rate
of discharge downstream which should reduce the size of drainage works required
downstream. It can substantially reduce the release of nutrients and pollutants to the
catchment. If sufficient open space is available, retaining and treating stormwater can
provide a cost effective means of upgrading stormwater drainage capacities with significant
environmental benefits.
Stormwater Reuse
Stormwater can be collected and stored, and then treated to a suitable level for a variety of
uses. Stormwater can be collected through individual rainwater tanks or through detention
basins. The temporary storage and reuse of flood waters will have the effect of attenuating
the peak flow rate of discharge downstream which should reduce the size of drainage
works required downstream. If sufficient open space is available, stormwater retention can
provide a cost effective means of upgrading stormwater drainage capacities, and reduce
pressure on treated water supplies and waterways. Rainwater tanks can supply many
indoor and outdoor domestic uses, and detention basins can be used for open space
irrigation or form part of the regional scheme.
9.7.4
Integrated Water Cycle Management Scenarios
Using the bundling process the above water management opportunities could be combined
into integrated scenarios. Table 9-21 presents examples of integrated scenarios.
Table 9-21 Integrated Water Cycle Management Scenarios for Tomakin and
Surrounds
Scenario
Management Option
Sewerage system upgrade
Minimal/ Traditional
2
3
"
"
"
"
"
Stormwater quality and quantity control
for high priority catchments
Stormwater quality and quantity – low
priority sub-catchments
"
Minimal/traditional Upgrade sewerage system.
Integrated Scenario 2 Upgrade sewerage system and reclaimed water reuse.
Integrated Scenario 3 Upgrade sewerage system, reclaimed water reuse and stormwater quality
and quantity control.
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Eurobodalla Integrated Water Cycle Management Strategy
The TBL assessment (Table 9-22) presents the comparative environmental, social and
economic benefits of each of the integrated scenarios.
Table 9-22 Triple Bottom Reporting for Tomakin and Surrounds
Minimal/
Traditional
2
3
Efficient use of fresh water resource
0
2
2
Minimises low flow water extractions
0
2
2
Minimises green house gas
emissions
2
3
3
Minimises pollutants being
discharged to the aquatic
environment
1
2
3
Minimises urban stormwater volumes
0
1
2
Ensure sustainable practices
0
2
3
Environmental Sum
3
12
15
Environmental Rank
3
2
1
Improves security of town water
supply
0
2
2
Improves the quality of drinking water
0
0
0
Improves urban water service levels
2
2
2
Increase public awareness of urban
water issues
0
2
3
Minimises non-compliance to policy
and legislation
3
3
3
Protects public health
3
3
3
Social Sum
8
12
13
Social Rank
3
2
1
3.9
5.7
6.2
Financial Rank
1
2
3
TBL Sum
6
6
5
TBL Rank
2
2
1
Outcomes
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV ($m over 30 years)
On a TBL basis the best option is option 3, the upgrading of the STP and stormwater quality
and quantity control for high and low priority catchments
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Eurobodalla Integrated Water Cycle Management Strategy
9.8
9.8.1
Moruya and Moruya Heads
Background
The Landscape
The town of Moruya is located in the central region of the Shire. It is the third largest town in
the Eurobodalla Shire and has the potential to become the industrial centre of the region.
The majority of the town development is concentrated on the southern side of the Moruya
River. The catchment supports a large dairy farming industry, aquaculture and recreational
activities. Figure 9-12 shows the location of Moruya.
Figure 9-12 Moruya Topographic Map
The population of Moruya recorded at the 2001 census was 2 314 for Moruya and 730 for
South Head and a total of 1 630 dwellings. The town supports the highest ratios of
permanent to holiday residents than other areas of the Shire. The 1996 housing monitor
stated there was 2 429 vacant lots in Moruya and Moruya Heads, with an annual demand of
34 lots. This analysis indicates that there is sufficient capacity for the predicted future
growth within the 30 year planning framework.
Existing Water Management Systems
The town is serviced by the regional water supply scheme. Water is supplied through the
6.0 ML Moruya Town 2 Reservoir and the 3.0 ML Moruya South Head Reservoir.
A recent upgrade of the system involved the construction of a new connection to transport
sewage from South Head to the Moruya STP. This coincided with the STP upgrade which
has increased its capacity from 4 000 EP to 8 000 EP. The plant upgrade involved
converting it from an intermittent extended aeration plant to a continuous extended aeration
plant. The STP now has chemical phosphorous, biological nitrogen removal capabilities.
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The UV disinfection process has been upgraded to tertiary lagoons and an effluent balance
tank with overflow to the storm catch ponds. The plant can treat three times average dry
weather flow. The current average dry weather flow is 600 kL/d. This is expected to
increase to 1 090 kL/d when all Moruya Head properties are connected.
Reclaimed water is currently being used for the irrigation of golf course. The remaining
treated water is discharged to Ryans Creek. A pollution reduction program has been issued
by the EPA to investigate the long term sustainability of the discharge to the estuary.
Council is planning to sewer the industrial estate to the north of Moruya.
Moruya is estimated to generate 6 413 kL/a stormwater with loadings of 5 350 kg/a of
nitrogen and 700 kg/a phosphorous. The urban centres contribute 8.3% of the total nitrogen
and 25.3% of the total phosphorous load to the system. This load is expected to increase by
40% over the next 25 years. Appropriate management of stormwater quality is required to
reduce this impact.
9.8.2
What Are the Issues?
The issues associated with the landscape and water management systems can be
classified into environmental, social and water infrastructure performance. These issues are
discussed below.
Environmental and Social Issues
!
Flood waters from the Moruya River inflow into the sewers increasing the potential
of sewer overflows and the associated health risks.
!
There is a pollution reduction program on the STP to investigate the effects of
nutrient loads on the estuary
!
Stormwater from Moruya is adversely impacting on the water quality in the estuary.
!
Moruya River is stressed under low flows due to town water and irrigation
extractions.
!
Localised flooding occurs in low lying areas.
!
The community perceives that the disposal of sewage effluent into the estuary has
a potential health risk to oyster growers and recreational users.
!
Farmers located in the Moruya catchment lack access to freshwater resources and
this is adversely affecting their productivity.
Water Infrastructure Performance Issues
Water Supply
An analysis of the reservoirs indicates that there is sufficient capacity to supply the year
2032 peak day demands.
Sewage
Available data suggests that pump stations 1,2,3,4,5,6 and 7 require upgrading to minimise
overflows and odour.
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9.8.3
How Do We Fix These Issues?
Overview
The landscape of this region could be managed sustainably through the implementation of
the appropriate planning controls. The issues of future development and acid sulfate soil
runoff could be managed by amending the local environmental and development control
plans.
There are a number of opportunities available to manage the water cycle of Moruya and
South Heads. Traditionally all opportunities available for the water supply, wastewater and
stormwater were often evaluated in isolation. In this strategy, all available opportunities
were identified and coarse screened (see Appendix C). The coarse screening process
recognises that there are immediate and short term measures, and medium to long term
water cycle management opportunities. The immediate and short term measures need to
be implemented as a matter of priority to achieve legislative compliance and best practice
standards. The short-listed medium to long term water cycle management opportunities
would in the long run deliver water cycle sustainability, public health protection and
improved service standards.
Short term Measures
The short term measures include:
!
Expanding the simple data management system into a comprehensive Shire wide
system that is able to record and store operational and performance monitoring
information.
!
Initiating regular and systematic monitoring of the operational parameters such as
daily water use, sewage flows, water quality etc and more strategic environmental
and social parameters.
!
Establishing a water supply reticulation network model to confirm pressure and
firefighting service standards.
!
Updating the asset registers to ensure the asset information is complete and up to
date. Underway
Medium to Long term Water Cycle Management Opportunities
The medium to long term opportunities are related to enhancing the sustainability of the
water cycle, protecting the public health and environment and improving the service
standards.
Table 9-23 presents the water cycle management opportunities, their relative capital and
present value costs over a 30-year period at an annual discount rate of 7%. Whilst the costs
are indicative only, the relative cost difference between the opportunities should be similar.
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Table 9-23 Costing of Management Opportunities for Moruya and Moruya Heads
Financial ($m)
Issues Management
Strategies
Upgrade pump stations
(Underway)
Sewer the industrial
estate (underway)
Social
Environmental
Capital
NPV @ 7%
$2.2
$2.3
Reduced potential for
odour complaints.
Lessened risk of
overflow.
Improved efficiency of
existing assets.
Limited footprint of
construction.
Lessened public health
risk.
Reduced risk of
overflows to sensitive
environment and water
bodies.
$1.1
$1.15
Economical
Lay a re-use pipeline
alongside the sewer
pipeline
Improved use of
valuable resource.
Limited footprint of
construction of this
option.
$0.40
$42
Lay a reuse pipe north
Saving of potable
(costly) treated water.
Return of resource to
the water cycle.
$0.45k
$0.47
Stormwater retention
quality and quantity
control for high priority
areas
Eliminates urban
flooding
Reduces pollution of
waterways
$0.056
$0.060
Stormwater quality and
quantity control for low
priority areas
Eliminates urban
flooding
Reduces pollution of
waterways
$1.0
$1.1
Sewage System Upgrade
The existing sewage treatment plant upgrade works were completed last year. The plant
has sufficient capacity for the next 30 years. Some sewer pipes and pump stations required
upgrading to overcome overflow and odour problems. This work is underway.
Stormwater Retention Basins
Stormwater retention basins are designed to collect and store flood run-off for release at a
controlled rate. The temporary storage of flood waters will have the effect of attenuating the
peak flow rate of discharge downstream which should reduce the size of drainage works
required downstream. Such temporary storage areas are sometimes formed naturally by
restrictions in the drainage systems and may be constructed artificially. If sufficient open
space is available, stormwater retention can provide a cost effective means of upgrading
stormwater drainage capacities.
Effluent Reuse
Wastewater can be treated to a suitable level for a variety of beneficial reuse. These
include industrial, agricultural, open space irrigation, non-potable domestic reuse and
indirect potable reuse. The opportunity exists in the Moruya area to utilise effluent for
agricultural and industrial reuse.
Integrated Water Cycle Management Scenarios
Using the bundling process the above water management opportunities can be combined
into integrated scenarios. The table below presents examples of integrated scenarios.
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Table 9-24 Integrated Water Cycle Management Scenarios for Moruya and Moruya
Heads
Management Option
Scenario
Traditional
2
3
"
"
Effluent reuse
"
"
Stormwater quality and quantity control
in high priority areas
"
"
Sewage system upgrade and extension
Stormwater quality and quantity control
in low priority areas
"
"
Minimal/traditional Sewerage system upgrade.
Integrated Scenario 2 Sewerage system upgrade, effluent reuse and stormwater in high
priority catchments.
Integrated Scenario 3 Sewerage system upgrade and effluent reuse and stormwater in
high and low priority catchments
The TBL assessment (Table 9-25) presents the comparative environmental, social and
economic benefits of each integrated scenarios.
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Table 9-25 Triple Bottom Line Reporting for Moruya and Moruya Heads
Minimal/
Traditional
2
3
Efficient use of fresh water resource
0
3
2
Minimises low flow water extractions
0
2
2
Minimises green house gas
emissions
2
2
2
Minimises pollutants being
discharged to the aquatic
environment
0
2
1
Minimises urban stormwater volumes
0
2
0
Ensure sustainable practices
0
3
2
Environmental Sum
2
14
9
Environmental Rank
3
1
2
Improves security of town water
supply
0
2
2
Improves the quality of drinking water
0
0
0
Improves urban water service levels
3
3
3
Increase public awareness of urban
water issues
0
2
3
Minimises non-compliance to policy
and legislation
3
3
3
Protects public health
3
3
3
Social Sum
9
13
14
Social Rank
3
2
1
3.5
4.4
5.5
Financial Rank
1
2
3
TBL Sum
7
5
6
TBL Rank
3
1
2
Outcomes
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV ($m over 30 years)
The triple bottom line assessment for Moruya is that the sewerage system upgrade, effluent
reuse and stormwater management in high priority catchments provide the best outcomes
based on the above criteria.
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9.9
9.9.1
Congo
Background
The Village Landscape
Congo is a small village located near Moruya. It is bounded by Congo Creek to the north
and the Tasman Sea to the east. The 2001 census recorded 143 people in Congo and 95
dwellings. The 1996 housing monitor recorded 27 vacant lots in Congo, with a predicted
annual demand of 2 lots. This analysis indicates that there will be a land shortage by 2010.
Figure 9-13 Location of Congo
Existing Water Management Systems
The village residents rely on rainwater tanks for their potable water needs. During periods of
drought and low rainfall the individual property owners purchase water externally, which in
most instances is sourced from the Shire’s regional water scheme. Some groundwater may
be available from the coastal sands, but the sustainability and capacity of this resource is
currently unknown.
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Figure 9-14 Aerial Photograph of Congo
The village residents manage their own on-site wastewater systems. According to Council’s
GIS, there is currently 80 on-site treatment facilities. 81% of these are septic tanks with
effluent disposal by adsorption trench. The remaining systems utilise aerated processes
that give higher levels of nutrient removal than septic systems.
Congo has 0.6 km of stormwater pipes with 84 stormwater pits recorded on the GIS.
Stormwater is not discharged to local rivers and there are no vulnerable ecosystems near
the village. An estimated 1 424 kL/a of stormwater is generated in Congo, containing
1 410 kg /a of nitrogen and 190 kg/a of phosphorous.
9.9.2
What Are the Issues?
The issues associated with the village landscape and water management system are
classified into environmental and social issues, and are discussed below. Other community
services related issues are not part of this study.
Social and Environmental Issues
9.9.3
!
The impact of sewage overflow pose a public health and environmental risks,
!
The land is not suitable for soil adsorption systems.
How Do We Fix the Problems?
Overview
It is vital that water management be undertaken in a sustainable manner. One important
mechanism to aid in the achievement of sustainable water management is through planning
controls. Many social and environmental issues such as acid sulfate soils can be addressed
through a local environmental plan or development control plan. Planning instruments also
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provide a forum for public review and participation with all plans requiring a mandatory
exhibition and submission period.
The traditional approach to water management is to separate water, wastewater and
stormwater and treat each in isolation. In this strategy, all available opportunities have been
identified and coarse screened (see Appendix C). The short listed water cycle management
opportunities are discussed below.
Water Cycle Management Opportunities
There are both short and medium term measures to improve the water cycle management
at Congo. The short term measures should be implemented as a matter of priority to
achieve best practice standard immaterial of the medium term opportunities.
Short Term Measures
The short term measures include:
!
Regular monitoring of on-site wastewater management systems for performance
and integrity
!
Systematic monitoring of local waterways and urban stormwater quality and
quantity.
!
Regular mail-outs of ways to maintain the on-site water and wastewater systems
including information on water conservation
The above short term measures are complimentary to the proposed medium term
measures and would help Council and the community to manage their water cycle more
sustainably.
Medium to Long Term Water Cycle Management Opportunities
Medium term opportunities are measures related to improving the long term sustainability of
the water cycle. In addition, these opportunities will also reduce public health and
environmental impacts and enhance the standards for the water services. Table 9-26
presents these opportunities along with their capital and present value at an annual
discount rate of 7%.
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Table 9-26 Costs of Opportunities for Congo
Cost Estimate
Capital ($m)
NPV @ 7% ($m)
-
$0.06
Harvested roof water supplemented with
reticulated water from the regional scheme
$0.84
$1.0
Provision of full reticulated water system from the
regional scheme
$1.1
$1.3
Improved management of existing on-site facilities
$0.12
$0.68
Enhanced management of existing on-site
1
facilities
$0.38
$0.51
Centralised management of effluent from on-site
1
facilities with local treatment
$2.3
$0.56
Local treatment and
2
management
$2.4
$0.78
Transfer to Moruya
$2.5
$0.67
Local treatment and
management with greywater
2
reuse of suitable systems
$2.4
$0.78
Improved management of existing water supply
Provision of
full reticulated
sewerage
system
Note 1: NPV’s for on-site systems are based on a rolling program commencing in 2003. NPV’s for sewering
Congo are based on work commencing in 2024. NPV’s for water are based on works commencing in 2003.
Note 2: The savings achieved by Council treating less effluent have not been taken take into account in the study
and the costs associated with greywater reuse are community costs
Improved Management of Present Water Supply
The reliability of the existing rainwater tank supply could be improved by conserving water
through more efficient use. Utilising water efficient appliances and fixtures such as dual
flush toilet, aerated taps, smart and efficient shower roses and washing machines are a few
examples. There may be the potential to utilise groundwater, this option however would
require further investigation.
Harvested Roofwater Supplemented with Reticulated Water
Congo is totally dependent upon rainwater tanks for its water supply. Installing a reticulated
system to supplement rainwater supplies would increase water security. This type of system
would offer a good quality potable water supply whilst continuing to utilise rainwater tanks
for uses such as toilet flushing, washing machines and gardening. Through supplying
reticulated potable water, significant community and health benefits would be expected. The
reticulated water could be sourced from the regional scheme
The pipes required for a supplemented reticulation scheme would be smaller than for a full
reticulated water supply provision. In this case the average annual and peak reticulated
water demands for the full development situation would be about 17 ML/a and 0.09 ML/d
respectively.
Provision of Full Reticulated Water Supply
Connecting Congo to the region’s water supply would require a 5 km pipeline from the
transfer main between Moruya and Bodalla along existing roads. As the houses currently
have rainwater tanks they could be retained and used for external water usage. If town
water is supplied to the village it is recommended that consideration be given to sewering of
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Eurobodalla Integrated Water Cycle Management Strategy
the town at this time, as additional water consumption will increase the on-site septic
systems loads.
Rainwater tanks can be less reliable than town water supplies and if gutters, roof surfaces
and tanks are not well maintained it may result in poor quality water. A full reticulated town
water supply would significantly reduce public health risks through ensuring that the water
supply meets the Australian Drinking Water Quality Guidelines. This option would also
eliminate the need for houses to import water during low rainfall and drought periods
In this case the average annual and peak reticulated water demands for the full
development situation would be about 20 ML/a and 0.14 ML/d respectively.
The scheme facilities necessary to provide a full reticulated water supply to Congo would be
similar to those required for a supplemented reticulated supply as discussed previously.
The facility and component sizes would however be required to be slightly larger. The
provision of larger pipes and facilities would enable the provision of fire fighting services at
minimal extra cost.
Improved Management of Existing On-site Wastewater Facilities
Sewage is currently treated by on-site systems. The seepage from existing on-site
wastewater management systems could be reduced by regularly emptying the contents of
the septic tanks and installing monitoring systems to prevent septic tank overflows and to
assess the integrity of the tanks. Regular pumpouts and monitoring has the potential to
minimise many of the environmental and public health impacts associated with the
operation of septic systems.
A single contract could be arranged by the Council or by the community such that the septic
tanks are pumped at set time intervals. This would cover both effluent and sullage
pumpout. The cost of this pumpout could be evenly split among the residents. To facilitate
pumping every tank would require a smaller holding tank or pumpout facility.
Although this opportunity would reduce the potential for waterway and aquifer
contamination, it may but result in additional community impacts, such as odours
associated with pumpouts and the movement of trucks in the neighbourhood.
A risk analysis undertaken for most of the villages of Eurobodalla indicated that Congo has
the least environmental and social risk associated with their current management practices.
Nevertheless, if Council adopts management solutions for the other small villages, there
may be economies of scale in considering the inclusion of Congo in a Shire-wide septic
management scheme.
Enhanced Management of Existing On-site Wastewater Facilities
There are several options available to upgrade the existing on-site wastewater
management systems to achieve greater public health and environmental outcomes. The
first option is to retain the existing septic tank and upgrade the on-site effluent management
system. An example of this would be the replacement of the adsorption trenches with lined
evapotranspiration beds, which achieve a higher level of water and nutrient uptake through
plants.
Another alternative is to upgrade the septic system to one that achieves nutrient removal
and therefore results in a higher quality effluent discharge (e.g. aerated tanks). This would
increase the potential uses available to the treated effluent.
Both these options would minimise the potential for groundwater contamination, and its
associated environmental problems as well as reducing the likelihood of public health
issues and odour complaints.
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Centralised Management of Effluent from On-site Facilities
As an alternative to providing a full reticulated sewage system, the effluent from existing onsite systems (e.g. septic tanks) could be collected and transported to a central treatment
facility. The pipes used may be smaller and could be laid in ground flatter and at a shallow
depth than conventional gravity sewerage, as the pipes carry only entrained solids thus
requiring minimal self cleaning velocity. The effluent collected form Moruya would be
transported to Moruya STP for treatment.
Provision of Full Reticulated Sewerage System
An alternative to providing any on-site treatment facilities is to transfer both the solids and
liquid through a common sewer transport network to Moruya STP. Unlike in the previous
opportunities the sewer transport pipes would need to be larger and possibly installed at a
greater depth. Installing sewerage reticulation to transfer to Moruya STP would require 9.5
km of pipeline along existing roads.
Provision of Full Reticulated Sewerage System with Grey Water Reuse
On-site systems that achieve a suitable level of greywater treatment would be maintained,
and blackwater only would be either transported to the Moruya STP using the reticulation
systems described above, or would undergo local treatment and management. The
resulting greywater could then be utilised for a variety of outdoor uses and for toilet flushing.
Maintaining current aerated systems in Congo for greywater reuse would reduce the
volume of wastewater requiring treatment by 0.86 ML/a. If in addition, current septic tanks
were converted to rainwater tanks for reuse purposes an additional 2.8 ML/a could be
saved. This in addition to reducing the volume of imported of reticulated water required for
Moruya, would reduce the hydraulic load on the Moruya STP. With the implementation of
appropriate monitoring systems, long term environmental and water resource sustainability
and public health protection could be achieved.
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9.10 Bodalla
9.10.1 Background
The Village Landscape
Bodalla is located just south of the Tuross River, approximately 7.5km west of Potato Point.
Urban development in Bodalla is concentrated along the Princess Highway, which also
serves as its major access. Figure 9-15 shows the locality of Bodalla.
Figure 9-15 Location of Bodalla
The land surrounding Bodalla consists of the Tuross River, Borang Lake, the Bodalla State
Forest and farmland. The 2001 census recorded 316 people in Bodalla and 200 dwellings.
The 1996 housing monitor stated there were 75 vacant lots in Bodalla, with an annual
demand of 1 lot. This indicates that there is sufficient land for urban expansion. In
investigating the integrated water options, allowance has been made for an annual demand
of 2 lots per annum. Figure 9-16 contains an aerial photograph of the area.
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Eurobodalla Integrated Water Cycle Management Strategy
Figure 9-16 Aerial Photograph of Bodalla
Existing Water Management Systems
Bodalla is connected to the regional water supply scheme, supplied through the 3 ML
Bodalla Park reservoir. This reservoir is capable of supply the estimated 2032 peak day
demand of 729 kL/d.
The village has on-site treatment for its sewage. According to the GIS, there are currently
133 on-site treatment facilities. The majority (84%), of these are septic tanks with effluent
disposal by adsorption trenches, which generally do not comply with the performance
objectives of Environmental and Health Protection Guidelines (1998). The remaining
systems utilise aerated processes that give higher levels of nutrient removal that septic
systems. A STP is proposed for Bodalla.
Bodalla has not been considered under the Shire’s stormwater management plan due to it’s
population being less than 1 000. There is 460 m of stormwater pipe recorded in Bodalla,
and eight discharge points. As the urban area is surrounded by agricultural land and the
stormwater must travel overland for more than 400 m to reach the nearest waterways, the
stormwater impacts from Bodalla are considered to be of low priority. An estimated
403 kL/a of stormwater is generated in Bodalla, containing 483 kg/a of nitrogen and 64kg/a
of phosphorous.
9.10.2 What Are the Issues
The issues associated with the village landscape and water management system are
classified into environmental and social issues, and are discussed below. Other community
issues are not part of this study.
Environmental Issues
!
172
There is currently pollution from on-site wastewater treatment systems due to small
lot sizes.
Eurobodalla Integrated Water Cycle Management Strategy
Social Issues
!
Current on-site wastewater management practices pose a public health risk
especially during rainy periods,
!
There are often odour complaints from residents,
!
The village has received funding for sewerage under the Small Towns Program
administered by DLWC, and the Department of Aboriginal Affairs and Council,
!
The village residents do not receive any water saving ‘tips’ or information on how to
better manage on-site wastewater management systems.
9.10.3 How Do We Fix the Problems?
Water Cycle Management Opportunities
There are both short and medium term measures to improve the water cycle management
at Bodalla. The short term measures should be implemented as a matter of priority to
achieve best practice standard immaterial of the medium term opportunities.
Short Term Measures
The short term measures include:
!
Regular monitoring of the on-site wastewater management systems for
performance and integrity,
!
Systematic monitoring of local waterways and urban stormwater quality and
quantity,
!
Regular mail-outs of ways to maintain the on-site water and wastewater systems
including information on water conservation.
The above short term measures are complimentary to the proposed medium term
measures and would help Council and the community to manage their water cycle more
sustainably.
Medium to Long Term Water Cycle Management Opportunities
Medium term opportunities are measures related to improving the long term sustainability of
the water cycle. In addition, these opportunities will also reduce public health and
environmental impacts and enhance the service standards for the water services. Table
9-27 presents these opportunities along with their capital and present value at an annual
discount rate of 7%.
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Table 9-27 Integrated Water Cycle Management Opportunities for Bodalla
Cost Estimate
Capital ($m)
NPV @ 7% ($m)
2.57
2.85
Package Treatment Plant
2.66
2.93
Package Treatment Plant
with greywater reuse of
1
suitable systems
2.66
2.93
Package Treatment Plant
with greywater reuse of
suitable systems and
roofwater harvesting
1
utilising disinfected tanks
2.66
2.93
Centralised management of effluent from onsite facilities
Provision of
full reticulated
sewerage
system
Note 1: As this is a strategy document, the saving s to Council for greywater reuse have not been costed. These
option will incur greater community costs
Centralised Management of Effluent from On-site Facilities
As an alternative to providing a full reticulated sewage system, the effluent from existing onsite systems (e.g. septic tanks) could be collected and transported to a central treatment
facility. This type of system relies on smaller pipes than those required for a conventional
reticulated sewerage system. Pipes can be laid in the ground at a lesser gradient and at a
more shallow depth than that of conventional gravity sewerage, as the solids are captured
by the on-site system and the pipes only need to carry liquid effluent. This option has been
priced with a package treatment plant and opportunistic reuse
Reed beds are local treatment option that may be viable in Bodalla. Constructed Reed beds
use passive biological systems to treat a variety of wastes such as human, animal, plant
and industrial wastes. It is an extremely effective system with many environmental benefits
when compared with traditional treatment options.
Provision of Full Reticulated Sewerage System
An alternative to on-site treatment sewerage facilities is to transfer wastewater through a
Centralised sewer transport network to a treatment plant as described above. Unlike in the
previous opportunities the sewer transport pipes would be larger and possibly installed at
greater depths.
Provision of Full Reticulated Sewerage System with Grey Water Reuse
On-site systems that achieve a suitable level of treatment for greywater would be
maintained, and blackwater only would be transported to the STP using the reticulation
systems described above. The resulting greywater could then be utilised for a variety of
outdoor uses and for toilet flushing. Maintaining current aerated systems in Bodalla for
greywater reuse would reduce the volume of wastewater requiring treatment by 1.3 ML/a.
This in addition to reducing the volume of imported of reticulated water required for Bodalla,
would reduce the hydraulic load on the future Bodalla STP. With the implementation of
appropriate monitoring systems, long term environmental and water resource sustainability
and public health protection could be achieved.
Provision of Full Reticulated Sewerage System with Grey Water Reuse and Roofwater
Harvesting
This opportunity incorporates the components of the previous opportunity. In addition to the
elements described above, systems that are not suitable for greywater reuse (e.g. septic
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Eurobodalla Integrated Water Cycle Management Strategy
tanks) would be de-sludged and disinfected and used to collect roofwater for non-potable
uses including garden watering and toilet flushing. This would result in an additional
3.16 ML/a of wastewater not requiring transportation and treatment. Together with
greywater reuse from aerated systems, a total of 4.36 ML/a could be saved.
Social and Environmental Aspects of Medium to Long Term Water Cycle
Management Opportunities
The TBL assessment in Table 9-28 provides the comparative environmental and social
benefits of each water cycle management opportunities.
Table 9-28 Social and Environmental Aspects of the Medium to Long Term
Opportunities for Bodalla
Social
Environmental
Limited additional infrastructure
required
Use of existing resources
Centralised management of effluent from
on-site facilities
Improved air quality and visual
character
Improved environmental
outcomes
Potential disturbance during
construction period
Limited additional infrastructure
required
Use of existing resources
Package Treatment
Plant
Improved air quality and visual
character
Potential disturbance during
construction period
Improved environmental
outcomes
More efficient use of
resources as part of the
regional reuse scheme
Limited additional infrastructure
required
Provision of full
reticulated
sewerage
system
Package Treatment
Plant with greywater
reuse of suitable
systems
Use of existing resources
Improved air quality and visual
character
Improved environmental
outcomes
More efficient use of
resources
Potential disturbance during
construction period
Package Treatment
Plant with greywater
reuse of suitable
systems and roofwater
harvesting utilising
disinfected tanks
Limited additional infrastructure
required
Use of existing resources
Improved air quality and visual
character
Improved environmental
outcomes
More efficient use of
resources
Potential disturbance during
construction period
9.10.4 Integrated Water Cycle Management Scenarios
Using the bundling process the above water management opportunities can be combined
into integrated scenarios presents examples of integrated scenarios. Table 9-29 presents
these integrated scenarios for Bodalla.
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Table 9-29 – Integrated Water Cycle Management Strategies for Bodalla
Traditional
Approach
Centralised management of effluent from on-site
facilities
Package Treatment Plant
Provision of
full reticulated
sewerage
system
2
3
4
"
"
Package Treatment Plant with
greywater reuse of suitable
systems
"
Package Treatment Plant with
greywater reuse of suitable
systems and roofwater harvesting
utilising disinfected tanks
"
Traditional Provision of full reticulated sewerage systems with a package treatment plant.
Integrated Scenario 2 Centralised management of effluent from on-site facilities
Integrated Scenario 3 Provision of full reticulated sewerage systems with a package treatment plant
with greywater reuse of suitable systems.
Integrated Scenario 4 Provision of full reticulated sewerage systems with a package treatment plant
with greywater reuse of suitable systems and roofwater harvesting utilising disinfected tanks.
9.10.5 Triple Bottom Line Assessment
Table 9-30 shows the triple bottom line reporting for the integrated options water cycle
options at Bodalla.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-30 Triple Bottom Line Assessment for Bodalla
Traditional
Approach
2
3
4
Efficient use of fresh water resource
0
1
2
2
Minimises low flow water extractions
0
0
2
2
Minimises green house gas emissions
1
2
2
2
Minimises pollutants being discharged to
the aquatic environment
3
3
3
3
Minimises urban stormwater volumes
0
0
0
2
Ensure sustainable land use practices
2
2
3
3
Environmental Sum
6
8
12
14
Environmental Rank
4
3
2
1
Improves security of town water supply
0
0
1
2
Improves the quality of drinking water
0
0
0
0
Improves urban water service levels
2
2
2
2
Increase public awareness of urban water
issues
1
2
3
3
Minimises non-compliance to policy and
legislation
3
3
3
3
Protects public health
3
3
3
3
Social Sum
9
10
12
13
Social Rank
4
3
2
1
2.93
2.57
2.93
2.93
Financial Rank
2
1
2
2
TBL Score
10
7
6
4
TBL Rank
4
3
2
1
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV ($m over 30 years)
According to the TBL assessment, the most suitable option for Bodalla is to incorporate
greywater reuse and roof water harvesting where appropriate, with a package treatment
plant.
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Eurobodalla Integrated Water Cycle Management Strategy
9.11 Potato Point
9.11.1 Background
The Village Landscape
Potato Point overlooks the Tasman Sea. The village is bounded by National Park with
Potato Point Beach to the north and Jamisons Beach to the south. Potato Creek flows to
the north of the village and there is an intermittent lagoon to the south west of the village.
The population recorded at Potato Point in the 2001 census was 133. There is limited land
available for development and there is no possibility for new land as the village is bounded
by National Park.
Figure 9-17 Potato Point Location
Existing Water Management Systems
Potato Point is supplied with water from the 3 ML Potato Point Reservoir, and is connected
to the regional water supply scheme. The Potato Point Reservoir has sufficient storage to
meet current and future peak day demands.
Sewage in Potato Point is treated by on-site systems. According to the GIS there are
currently 120 on site treatment facilities. Of these nearly 70% are septic tanks with effluent
disposal by adsorption trench and an additional 8% are septic tanks with effluent pump-out.
The remaining systems utilise aerated processes that result in a higher level of nutrient
removal than septic systems.
There is no stormwater infrastructure recorded in Council’s GIS. Stormwater is likely to flow
overland until adsorbed by the sandy soils or until it reaches Potato Creek. An estimated
207 kL/a of stormwater is generated in Potato Point, containing 250 kg/a of nitrogen and
30 kg/a of phosphorous.
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Eurobodalla Integrated Water Cycle Management Strategy
Figure 9-18 Aerial Photograph of Potato Point
9.11.2 What Are the Issues?
The issues associated with the village landscape and water management systems are
classified into environmental and social issues, and are discussed below. Other community
services related issues are not part of this study.
Social and Environmental Issues
!
Insufficient sewage treatment through on-site systems may result in environmental
degradation,
!
A risk assessment of the social and environmental issues for most of the villages
ranked Potato Point as the third highest priority for management intervention.
9.11.3 How Do We Fix the Problems
Overview
It is vital that water management be undertaken in a sustainable manner. One important
mechanism to aid in the achievement of sustainable water management is through planning
controls. Many social and environmental issues such as acid sulfate soils and medium
density housing can be addressed through a local environmental plan or development
control plan. Planning instruments also provide a forum for public review and participation
with all plans requiring a mandatory exhibition and submission period.
The traditional approach to water management is to separate water, wastewater and
stormwater and treat each in isolation. In this strategy, all available opportunities have been
identified and coarse screened (see Appendix C). The short listed water cycle management
opportunities are discussed below.
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Eurobodalla Integrated Water Cycle Management Strategy
Water Cycle Management Opportunities
There are both short and medium term measures to improve the water cycle management
at Potato Point. The short term measures should be implemented as a matter of priority to
achieve best practice standard immaterial of the medium term opportunities.
Short Term Measures
The short term measures include:
!
Regular monitoring of the on-site wastewater management systems for
performance and integrity,
!
Systematic monitoring of local waterways and urban stormwater quality and
quantity,
!
Regular mail-outs of ways to maintain on-site wastewater systems including
information on water conservation.
The above short term measures are complimentary to the proposed medium term
measures and would help Council and the community to manage their water cycle more
sustainably.
Medium to Long Term Water Cycle Management Opportunities
Medium term opportunities are measures related to improving the long term sustainability of
the water cycle. In addition, these opportunities will also reduce public health and
environmental impacts and enhance the service standards for the water services. Table
9-31 presents these opportunities along with their capital and present value at an annual
discount rate of 7%.
Table 9-31 Integrated Water Cycle Management Opportunities for Potato Point
Cost Estimate
Capital ($m)
NPV @ 7% ($m)
Improved management of existing on-site facilities
$0.18
$0.96
Enhanced management of existing on-site
facilities
$0.57
$0.77
Provision of
centralised effluent
management
Transfer to Bodalla
system
$1.72
$0.68
Transfer to Bodalla
system
$1.9
$0.72
Transfer to Bodalla STP
with greywater reuse
and roof water
harvesting
$1.9
$0.72
Provision of full
reticulated sewerage
system
Note 1: As this is a strategy document, the saving s to Council for greywater reuse have not been costed. This
option will incur greater community costs
Note: NPV’s for on-site systems are based on a rolling program commencing in 2003. NPV’s for sewering Potato
Point are based on work commencing in 2020
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Eurobodalla Integrated Water Cycle Management Strategy
Improved Management of Existing On-site Wastewater Facilities
Sewage is currently treated by on-site systems. The seepage from existing on-site
wastewater management systems could be reduced by regularly emptying the contents of
the septic tanks and installing monitoring systems to prevent septic tank overflows and to
assess the integrity of the tanks.
A single contract could be arranged by the Council or by the community such that the septic
tanks are pumped at set time intervals. This would cover both effluent and sullage
pumpout. The cost of this pumpout could be evenly divided between the residents. To
facilitate pumping every tank would require a smaller holding tank or pumpout facility.
Although this opportunity would reduce the potential of waterway and aquifer contamination,
it may but result in additional community impacts, such as odour complaints associated with
pumpouts, and the movement of trucks in the neighbourhood.
Enhanced Management of Existing On-site Wastewater Facilities
There are several options available to upgrade the existing on-site wastewater
management systems to achieve greater public health and environmental outcomes. The
first option is to retain the existing septic tanks and upgrade the on-site effluent
management system. An example of this would be the replacement of the adsorption
trenches with lined evapotranspiration beds, which achieve a higher level of water and
nutrient uptake through plants.
Another alternative is to upgrade the septic system to one that achieves nutrient removal
and therefore results in a higher quality effluent discharge (e.g. aerated tanks). This would
increase the potential uses of the treated effluent.
Both these options would minimise the potential of groundwater contamination, and its
associated environmental problems as well as reducing the likelihood of public health
issues and odour complaints.
Centralised Management of Effluent from On-site Facilities
As an alternative to providing a full reticulated sewage system, the wastewater from existing
on-site systems (e.g. septic tanks) could be collected and transported to a central treatment
facility. This type of system relies on smaller pipes than those required for a conventional
reticulated sewerage system. Pipes can be laid in the ground at a lesser gradient and at a
more shallow depth than that of conventional gravity sewerage, as the solids are captured
by the on-site system and the pipes only need to carry liquid wastewater. The wastewater
would be transported to Bodalla STP for treatment.
Reed beds are local treatment option that may be viable in Potato Point. Constructed Reed
beds use passive biological systems to treat a variety of wastes such as human, animal,
plant and industrial wastes. It is an extremely effective system with many environmental
benefits when compared with traditional treatment options.
Provision of Full Reticulated Sewerage System
An alternative to treating sewerage on-site is to transfer wastewater (i.e. black and grey
water) through a centralised sewer transport network to either a local treatment facility as
discussed for the previous opportunity, or to the (proposed) Bodalla STP.
Unlike in the previous opportunity the sewer transport pipes would be required to be larger
and possibly need to be installed at greater depths.
Appendix P provides a detailed description of the available transport and local treatment
options. The shortlisted reclaimed water management options are the same as those
discussed for the above opportunity.
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Eurobodalla Integrated Water Cycle Management Strategy
The costs in Table 9-31 is based on modified gravity transport system with transfer to the
Bodalla STP.
Provision of Full System with Greywater Reuse
On-site systems that achieve a suitable level of treatment for greywater would be
maintained, and blackwater only would be transported to the Bodalla STP using the
reticulation systems described above. The resulting greywater could then be utilised for a
variety of outdoor uses and for toilet flushing. Maintaining current aerated systems in Potato
Point for greywater reuse would reduce the volume of wastewater requiring treatment by
2.7 ML/a. This in addition to reducing the volume of imported of reticulated water required
for Potato Point, would reduce the hydraulic load on the Bodalla STP. With the
implementation of appropriate monitoring systems, long term environmental and water
resource sustainability and public health protection could be achieved.
Provision of Full System with Grey Water Reuse and Roof water harvesting
This option is as per the previous option, with the incorporation of rainwater tanks. Systems
that are not suitable for greywater reuse (e.g. septic tanks) would be de-sludged and
disinfected and used to collect roofwater for non-potable uses including garden watering
and toilet flushing. This would result in an additional 3.68 ML/a of wastewater not requiring
transportation and treatment at the Bodalla STP. Together with greywater reuse from
aerated systems, a total of 6.38 ML/a could be saved.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-32 Social and Environmental Aspects of the Medium to Long Term
Opportunities for Potato Point
Opportunities
Improved management of existing
on-site facilities
Social
Associated odour and noise
impacts
Inconvenience of pumpout trucks
in the area
Environmental
Improved environmental
outcomes, minimises the
incidence of septic effluent
contaminating groundwater
Improved air quality and visual
character
Enhanced management of existing
on-site facilities
Centralised
management
of effluent
from on-site
facilities
Local treatment
and management
(Reed beds)
Transfer to
Bodalla system
with greywater
reuse
Provision of
full reticulated
sewerage
system
Enhanced aesthetic appeal for
the local area, good for tourism
and recreational activities
Reduced impact to local
waterways and the environment
Would encourage local reuse and
recycling
Solution would be tailored to
match local requirements
Limited additional infrastructure
required
Use of existing resources
Short term inconvenience for
residents during construction i.e.
noise, vehicle movement
Less overall environmental
impacts than conventional gravity
systems
Improved quality of effluent
discharged to environment
Increased opportunities for
effluent reuse
Possible environmental impact
during construction
Significantly reduced likelihood of
groundwater contamination
Limited additional treatment
infrastructure required
Transfer to
Bodalla system
and grey water
reuse and
roofwater
harvesting
Existing resources can be utilised
Improved quality of effluent
discharged to environment
Short term inconvenience for
residents during construction i.e.
noise, vehicle movement
Increased opportunities for
effluent reuse
Reduced demand on reticulated
water resources
Reduced hydraulic and biological
loads on the Bodalla sewerage
system
Possible environmental impact
during construction
Significantly reduced likelihood of
groundwater contamination
9.11.4 Integrated Water Cycle Management Scenarios
Using the bundling process the above water management opportunities can be combined
into integrated scenarios. Table 9-33 presents examples of integrated scenarios. Other
scenarios may be developed and considered in the subsequent study phase.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-33 Integrated Scenarios for Potato Point
Minimal
Improved management of existing onsite facilities
Traditional
Solution
4
5
"
Local treatment
and management
(Reed beds)
Transfer to
Bodalla system
Provision of full
reticulated
sewerage system
3
"
Enhanced management of existing onsite facilities
Centralised
management of
effluent from onsite facilities
Integrated Scenarios
"
"
Transfer to
Bodalla system
with greywater
reuse and roof
water harvesting
"
Minimal Improved management of existing on-site facilities.
Traditional Provision of full reticulated sewerage system with transfer to the Bodalla system and
greywater reuse.
Integrated Scenario 3 Enhanced management of existing on-site facilities.
Integrated Scenario 4 Centralised management of effluent from on-site facilities with local treatment
and management.
Integrated Scenario 5 Provision of full reticulated sewerage system with transfer to the Bodalla
system greywater reuse and roofwater harvesting.
The TBL assessment (Table 9-34) presents the comparative environmental, social and
economic benefits of each integrated scenarios.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-34 Triple Bottom Line Assessment of Scenarios for Potato Point
Minimal
Traditional
Approach
3
4
5
Efficient use of fresh water
resource
0
1
0
1
2
Minimises low flow water
extractions
0
2
0
1
2
Minimises green house gas
emissions
1
1
2
2
2
Minimises pollutants being
discharged to the aquatic
environment
2
2
2
2
2
Minimises urban stormwater
volumes
0
0
0
0
2
Ensures sustainable
practices
1
2
2
2
3
Environmental Sum
4
8
6
8
13
Environmental Rank
5
2
4
2
1
Improves security of town
water supply
0
1
0
1
2
Improves the quality of
drinking water
0
0
0
0
0
Improves urban water
service levels
1
3
2
3
3
Increase public awareness
of urban water issues
2
2
2
2
3
Minimises non-compliance
to policy and legislation
1
3
3
3
3
Protects public health
2
3
3
3
3
Social Sum
6
12
10
12
14
Social Rank
5
2
4
2
1
0.96
0.72
0.77
0.68
0.72
Financial Rank
1
2
3
1
2
TBL Score
14
6
11
5
4
TBL Rank
5
2
4
2
1
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV ($m over 30 years)
The preferred option for Potato Point according to the above assessment criteria is the
provision of a full reticulated system with transfer to the Bodalla STP and incorporating
greywater reuse and roof water harvesting where appropriate.
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Eurobodalla Integrated Water Cycle Management Strategy
9.12 Dalmeny Kianga and Narooma
9.12.1 Background
The Landscape
Dalmeny, Kianga and Narooma are located in the south of the Shire. The towns are
situated on sensitive waterways which include the Wagonga inlet, and the Kianga, Little and
Nangudga Lakes. Figure 9-19 shows the location of Dalmeny, Kianga and Narooma.
Figure 9-19 Dalmeny, Kianga and Narooma Topographic Map
The 2001 census recorded 1 785 people in Dalmeny, 1 145 in Kianga and 2 267 in
Narooma. There are 747 lots available at Dalmeny, 273 at Kianga, 172 at North Narooma
and 869 at Narooma. This is sufficient for to meet the projected growth of the area over the
30 year planning timeframe.
Existing Water Management Systems
Dalmeny, Kianga and Narooma are connected to the regional water supply system.
The Kianga STP services the Dalmeny, Kianga and Narooma communities. It has a design
capacity of 12 000 EP and currently uses a continuous and intermittent extended aeration
processes decommissioned. The plant utilises secondary treatment processes and natural
disinfection prior to discharging to the ocean. Similar to the other STPs, stabilised and
dewatered biosolid is used in the rehabilitation of Council’s landfill.
An estimated 8 490 kL/a of stormwater is generated in Narooma. The subcatchment that
drains to Little Lake has been ranked as a priority catchment for the region. Dams on the
Narooma golf course are used to retain stormwater for on-site reuse. Figure 9-20 shows the
stormwater sub-catchments for this area.
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Eurobodalla Integrated Water Cycle Management Strategy
Figure 9-20 Dalmeny/Kianga/Narooma Stormwater Sub-Catchments
9.12.2 What Are the Issues?
The issues associated with the landscape and water management systems can be
classified into environmental, social and water infrastructure performance. These issues are
discussed below.
Environmental and Social Issues
!
Wagonga Inlet contains oyster leases. The discharge of sewage and stormwater
runoff to the environment poses not only a risk to public health but a risk also of
productivity loss to the oyster industry,
!
The community perception is that the treatment works discharges to the adjacent
lake, whereas the effluent is actually discharged into the ocean,
!
Overflow may occur from pump stations during power outages,
!
There is a history of community complaints about odours from the inlet works of the
STP.
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Eurobodalla Integrated Water Cycle Management Strategy
Water Infrastructure Performance Issues
Water Supply
Narooma town reservoir does not have sufficient capacity to supply future peak day
demands in isolation, however the North Narooma Reservoir has sufficient capacity to
supply both North Narooma and Narooma.
Sewage
Pump stations 4,5,19 are prone to surcharge during power outages and some pump
stations may need upgrading to cope with future growth. The Kianga STP is predicted to
reach its design capacity in 2011. Odour from the pump stations has historically been an
issue. The system has recently been upgraded with biological deodorisation beds, which
appears to have addressed the issue, although the system has not yet undergone a holiday
loading since their construction.
Stormwater
The stormwater generated in Narooma is expected to carry 7.6 tonnes per annum of
nitrogen and 1.20 tonnes per annum of phosphorous. These nutrients have the potential to
affect the health of Wagonga Inlet and the surrounding waterways.
9.12.3 How Do We Fix these Issues?
Overview
There are a number of opportunities to manage the water cycle of the towns of Dalmeny
Kianga and Narooma and the surrounding landscape. The traditional approach to water
management is to separate water, wastewater and stormwater and treat each in isolation.
In this plan, all available opportunities have been identified and coarse screened (see
Appendix C). The coarse screening process recognises that there are immediate and short
term measures, and medium to long term water cycle management opportunities. The
immediate and short term measures need to be implemented as a matter of priority to
achieve legislative compliance and best practice standards. The short-listed medium to
long term water cycle management opportunities would in the long run deliver water cycle
sustainability, public health protection and improved service standards.
Immediate Measures
To reduce the risk of potential overflows one of the following strategies may be employed;
!
Provide additional storage at the critical pump stations and/or,
!
Ensuring a more reliable main power supply system or stand-by power.
Short term Measures
The short term measures include:
188
!
Expanding the simple data management system into a comprehensive Shire wide
system to record and store operational and performance monitoring information.
!
Initiating regular and systematic monitoring of operational parameters such as daily
water use, sewage flows, water quality etc and more strategic environmental and
social parameters.
!
Establishing a water supply reticulation network model to confirm pressure and
firefighting service standards.
Eurobodalla Integrated Water Cycle Management Strategy
!
Updating the asset registers to ensure the asset information is complete and up to
date.
!
Improve the reliability and system operation of the sewerage systems through
telemetry controls, oxygen injection and power supply.
Medium to Long term Water Cycle Management Opportunities
Enhancements to the STP capacity and effluent quality using one of the following
measures,
!
Based on Studies done for Batemans Bay and Tomakin it appears that the
performance of Kianga plant could be optimised by chemical dosing to
accommodate the projected loads,
!
Adding a parallel secondary treatment facility,
!
Odour concerns could be addressed through:
−
Odour bed and scrubber to neutralise the smell at plant inlet works,
−
Protection of buffer zone from future development.
Table 9-35 Medium to Long Term Water Cycle Management Opportunities for
Dalmeny, Kianga and Narooma
Costs $m
Opportunity
Capital
NPV@7%
1.9
2.0
3.8
2.7
Stormwater quantity and quality control measures for
high priority sub-catchment
2.2
2.6
Stormwater quality and quantity control for low priority
sub-catchments
1.0
1.1
Local urban open space stormwater reuse
2.64
2.8
Option 1 – Plant performance
optimisation strategy
Enhancement to
sewerage system
management
-
Reticulation improvement to
fix major I/I problem
-
UV plant to improve effluent
quality
-
Optimise treatment plant
operation
Option 2 – Traditional strategy
-
Reticulation improvement to
fix major I/I problem
-
UV plant to improve effluent
quality
-
Parallel treatment train
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Eurobodalla Integrated Water Cycle Management Strategy
Improve current Sewage Treatment System
This option involves upgrading the Kianga STP to address the long term odour impacts and
to meet operational compliance. Upgrading the plant would include the medium to long term
management measures identified above, and pump station improvements.
Increase Treatment Capacity
Kianga STP requires upgrading to meet future demands. This could be achieved by
constructing a parallel treatment facility or by optimising the existing treatment train.
Stormwater Quality and Quantity Control measures
Stormwater can be collected and stored, and then treated for release at a controlled rate.
The temporary storage of flood waters will have the effect of attenuating the peak flow rate
of discharge downstream which should reduce the size of drainage works required
downstream. It can substantially reduce the release of nutrients and pollutants to the
catchment. If sufficient open space is available, retaining and treating stormwater can
provide a cost effective means of upgrading stormwater drainage capacities with significant
environmental benefits.
Stormwater Reuse
Stormwater can be collected and stored, and then treated to a suitable level for a variety of
uses. Stormwater can be collected through individual rainwater tanks or through detention
basins. The temporary storage and reuse of flood waters will have the effect of attenuating
the peak flow rate of discharge downstream which should reduce the size of drainage
works required downstream. If sufficient open space is available, stormwater retention can
provide a cost effective means of upgrading stormwater drainage capacities, and reduce
pressure on treated water supplies and waterways. Rainwater tanks can supply many
indoor and outdoor domestic uses, and detention basins can be used for open space
irrigation or form part of the regional scheme.
Table 9-36 Social and Environmental Aspects of the Medium to Long Term
Opportunities for Dalmeny, Kianga and Narooma
Opportunity
Social
Environmental
Reduced potential for odour
complaints.
Improve current sewage system
management
Lessened risk of overflow.
Improved efficiency of existing
assets
Limited footprint of construction.
Will meet future demand loads
Reduces stormwater impacts
and flooding.
Stormwater quality and quantity
control measures
Cost effective means of
upgrading stormwater
capacities.
Help protect oyster industry with
improved run-off entering local
waterways.
Improved public health
outcomes
190
Controls pollutants entering the
environment.
Improves quality of local
waterways
Reduces erosion from increased
run-off.
Allows for future reuse
opportunities.
Eurobodalla Integrated Water Cycle Management Strategy
Opportunity
Social
Environmental
Reduces stormwater impacts
and flooding.
Controls pollutants entering the
environment.
Cost effective means of
upgrading stormwater
capacities.
Improves quality of local
waterways
Stormwater reuse
Help protect oyster industry with
improved run-off entering local
waterways.
Improved public health
outcomes
Reduces erosion from increased
run-off.
Efficient use of water resources.
Reduces pressure on water
supply sources for irrigation
purposes
9.12.4 Integrated Water Cycle Management Scenarios
Using the bundling process, the above water management opportunities can be combined
into integrated scenarios. Table 9-37 presents some examples of integrated scenarios.
Table 9-37 Integrated Water Cycle Management Scenarios for Dalmeny, Kianga and
Narooma
Management Option
Improve current sewage system
management
Stormwater quantity and quality control
measures for high priority areas
Scenario
Minimal/
Traditional
2
3
"
"
"
"
"
Stormwater quantity and quality control
measures for low priority areas
"
Stormwater harvesting and reuse for open
space, playing fields and golf course
irrigation
"
Minimal/traditional Improve current sewage treatment system and increase treatment capacity.
Integrated Scenario 2 Improve current sewage treatment system, increase treatment capacity and
incorporate stormwater quality and quantity control measures.
Integrated Scenario 3 Improve current sewage treatment system, increase treatment capacity,
incorporate stormwater quality and quantity control measures and stormwater reuse.
The TBL assessment (Table 9-38) presents the comparative environmental, social and
economic benefits of each integrated scenario example.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-38 Triple Bottom Line Assessment of Scenarios for Dalmeny, Kianga and
Narooma
Traditional
Approach
2
3
Efficient use of fresh water resource
0
2
3
Minimises low flow water extractions
0
0
3
Minimises green house gas emissions
2
2
1
Minimises pollutants being discharged to
the aquatic environment
1
3
3
Minimises urban stormwater volumes
0
3
3
Ensures sustainable practices
1
2
3
Environmental Sum
4
12
16
Environmental Rank
3
2
1
Improves security of town water supply
0
0
2
Improves the quality of drinking water
0
0
0
Improves urban water service levels
2
3
3
Increase public awareness of urban
water issues
1
2
3
Minimises non-compliance to policy and
legislation
2
2
2
Protects public health
2
3
3
Social Sum
7
10
13
Social Rank
3
2
1
2.7
4.6
8.5
Financial Rank
1
2
3
TBL Score
7
6
5
TBL Rank
3
2
1
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV ($m over 30 years)
According to the TBL assessment, integrated option 3 would produce the best outcome in
terms of the environmental, social and financial criteria. Option 3 represents the option with
the greatest integration and includes improving the current sewage treatment system,
increasing treatment capacity; incorporating stormwater quality and quantity control
measures and stormwater reuse.
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Eurobodalla Integrated Water Cycle Management Strategy
9.13 Mystery Bay
9.13.1 Background
The Village Landscape
Mystery Bay is located in the south easterly region of the Shire. The village is situated on
the coastline at Cape Dromedary and is surrounded by farmland to the west. Access to the
village is from the Princess Highway, see Figure 9-21 below.
Figure 9-21 Mystery Bay
According to the 2001 census, the population of Mystery bay is 185, and there are 111
dwellings. The 1996 housing monitor stated there were 243 vacant lots in Mystery Bay, with
an annual demand of 6 lots. This analysis indicates that there is sufficient land available for
release to supply the predicted population growth.
Existing Water Management Systems
Mystery Bay is connected to the regional water supply scheme through the 1.2 ML Mystery
Bay Reservoir. This has sufficient capacity to supply the predicted 2032 peak day demand
of 252 kL/d.
The village is serviced by on site systems. According to the GIS, there are currently 93 onsite treatment facilities. Over 50% of these are septic tanks with effluent disposal by
adsorption trench, which are unsuitable for the soil conditions, and nearly an additional 10%
are septic tanks with effluent pump-out. The remaining systems utilise aerated processes
that give higher levels of nutrient removal than septic systems.
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Eurobodalla Integrated Water Cycle Management Strategy
There are 1.6 km of stormwater pipes and 7 discharge points in Mystery Bay. There are no
permanent streams nearby however 5 of the discharge points discharge directly to
intermittent streams and two of these to the Swamp Oak vulnerable ecosystem. An
estimated 340 kL/a of stormwater is generated in Mystery Bay, containing 409 kg/a of
nitrogen and 55 kg/a of phosphorous.
9.13.2 What Are the Issues?
The issues associated with the village landscape and water management system are
classified into environmental and social issues, and are discussed below. Other community
services related issues are not part of this study.
Environmental Issues
!
Risk of sewage overflows from on site systems to sensitive waterbodies,
!
Urban stormwater discharge is impacting on intermittent streams,
!
Clay soils in the area have a low septic adsorption capacity, resulting in the
potential contamination of local waterways.
Social Issues
!
The current sewage management systems / practices poses a risk to public health,
!
Odour complaints from residents from on site systems,
!
The water supply and wastewater systems are experiencing pressure from
population growth,
!
The community relies on the pristine nature of the catchment for its recreational
activities.
9.13.3 How Do We Fix The Problems?
Water Cycle Management Opportunities
There are both short and medium term measures to improve the water cycle management
at Mystery Bay. The short term measures should be implemented as a matter of priority to
achieve best practice standard immaterial of the medium term opportunities.
Short Term Measures
The short term measures include:
!
Regular monitoring of on-site wastewater management systems for performance
and integrity,
!
Systematic monitoring of local waterways and urban stormwater quality and
quantity,
!
Regular mail-outs of ways to maintain after the on-site water and wastewater
systems including information on water conservation.
The above short term measures are complimentary to the proposed medium term
measures and would help Council and the community to manage their water cycle more
sustainably.
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Eurobodalla Integrated Water Cycle Management Strategy
Medium to Long Term Water Cycle Management Opportunities
Medium term opportunities are measures related to improving the long term sustainability of
the water cycle. In addition, these opportunities will also reduce public health and
environmental impacts and enhance the service standards for the water services. Table
9-39 presents these opportunities along with their capital and present value at an annual
discount rate of 7%.
Table 9-39 Cost Estimates of Medium to Long Term Water Cycle Management
Opportunities for Mystery Bay
Cost Estimate
Capital ($m)
NPV @ 7% ($m)
Improved management of existing on-site facilities
0.10
0.56
Enhanced management of existing on-site
facilities
0.446
0.60
Local treatment and
management
2.44
0.74
Transfer to Kianga system
2.27
0.68
Local treatment and
management
2.44
0.94
Local treatment and
management with greywater
2
reuse
2.44
0.94
Transfer to Kianga system
2.45
0.722.1
Centralised
management of
effluent from onsite facilities
Provision of full
reticulated
sewerage system
Note 1: NPV’s for on-site systems are based on a rolling program commencing in 2003. NPV’s for sewering
Mystery Bay are based on work commencing in 2021
Note 2: The savings achieved by Council treating less effluent have not been taken take into account in the study
and the costs associated with greywater reuse are community costs
Improved Management of Existing On-site Wastewater Facilities
The seepage from existing on-site wastewater management systems could be reduced by
regularly emptying the contents of the septic tanks and putting monitoring systems in place
to prevent septic tank overflows and to assess the integrity of the tanks.
A single contract could be arranged by the Council or by the community such that the septic
tanks are pumped at set time intervals. This would cover both effluent and sullage
pumpout. The cost of this pumpout could be evenly split between the residents. To facilitate
pumping every tank would need to be provided with a smaller holding tank or pumpout
facility.
This opportunity would remove the issue of effluent contaminating the aquifer and
waterways, but raises community issues in relation to odour during pumpout and frequent
movement of trucks in the neighbourhood.
Enhanced Management of Existing On-site Wastewater Facilities
There are several options available to upgrade the existing on-site wastewater
management systems to achieve greater public health and environmental outcomes. The
first option is to retain the existing septic tank and upgrade the on-site effluent management
system. An example of this would be the replacement of the adsorption trenches with lined
evapotranspiration beds, which achieve a higher level of water and nutrient uptake through
plants.
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Eurobodalla Integrated Water Cycle Management Strategy
Another alternative is to upgrade the septic system to one that achieves nutrient removal
and therefore results in a higher quality effluent discharge (e.g. aerated tanks). This would
increase the potential uses of the treated effluent.
Both these options would minimise the potential of environmental degradation as well as
reducing the likelihood of public health issues and odour complaints.
Centralised Management of Effluent from On-site Facilities
As an alternative to providing a full reticulated sewage system, the effluent from existing onsite systems (e.g. septic tanks) could be collected and transported to a central treatment
facility. This type of system relies on smaller pipes than those required for a conventional
reticulated sewerage system. Pipes can be laid in the ground at a lesser gradient and at a
more shallow depth than that of conventional gravity sewerage, as the solids are captured
by the on-site system and the pipes only need to carry liquid wastewater.
Appendix P provides a description of the available effluent transport and local treatment
options. The effluent could also be transported to Narooma STP for treatment.
The reclaimed water could also be managed in a number of ways, if the effluent was
treated at a local treatment facility. Appendix C provides a detailed description of the
available management options. Preliminary appraisal suggests dunal infiltration and
agricultural reuse are suitable disposal methods. Costs in Table 14.1 are based on
Centralised effluent drainage (CED) for transport, a reed bed system for treatment and
dunal infiltration as an opportunity or transfer to the Kianga STP as an alternative.
Provision of Full Reticulated Sewerage System
An alternative to on-site sewerage treatment facilities is to transfer wastewater through a
centralised sewer transport network to either a local package treatment facility or to Kianga
STP.
Unlike in the previous opportunity the sewer transport pipes would be larger and possibly
installed at greater depths.
Appendix P provides a detailed description of the available transport and local treatment
options. The shortlisted reclaimed water management options are the same as those
discussed for the above opportunity.
Costs in Table 9-39 are based on a modified gravity transport system, a local package
extended aeration treatment plant and dunal infiltration.
Provision of a Full reticulated sewerage system with greywater reuse and roof water
harvesting
On-site systems that achieve a suitable level of treatment for greywater would be
maintained, and blackwater only would be transported to the STP using the reticulation
systems described above. The resulting greywater could then be utilised for a variety of
outdoor uses and for toilet flushing. Maintaining current aerated systems in Mystery Bay for
greywater reuse would reduce the volume of wastewater requiring treatment by 3.35 ML/a.
This in addition to reducing the volume of imported of reticulated water required for Mystery
Bay, would reduce the hydraulic load on the Kianga STP. With the implementation of
appropriate monitoring systems, long term environmental and water resource sustainability
and public health protection could be achieved.
Systems that are not suitable for greywater reuse (e.g. septic tanks) would be de-sludged
and disinfected and used to collect roofwater for non-potable uses including garden
watering and toilet flushing. This would result in an additional 2.32 ML/a of wastewater not
requiring transportation and treatment at the Kianga STP. Together with greywater reuse
from aerated systems, a total of 5.67 ML/a could be saved.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-40 Social and Environmental Aspects of The Medium to Long Term
Opportunities for Mystery Bay
Opportunities
Improved management of existing
on-site facilities
Social
Associated odour and noise
impacts
Inconvenience of pumpout trucks
in the area
Environmental
Improved environmental
outcomes, minimises the
incidence of septic effluent
contaminating groundwater
Improved air quality and visual
character
Enhanced management of existing
on-site facilities
Enhanced aesthetic appeal for
the local area, good for tourism
and recreational activities
Reduced impact to local
waterways and the environment
Potential disturbance during
construction period
Local treatment
and
management
Centralised
management of
effluent from onsite facilities
Transfer to
Narooma
system
Solution would be tailored to
match local requirements
Potential disturbance during
construction period
Limited additional treatment
infrastructure required
Existing resources can be utilised
Potential disturbance during
construction period
Solution would be tailored to
match local requirements
Local treatment
and
management
Solution would be tailored to
match local requirements
Larger capital investment
required
Short term inconvenience for
residents during construction i.e.
noise, vehicle movement
Would encourage local reuse and
recycling
Less overall environmental
impacts than conventional gravity
systems
Possible environmental impact
during construction
Less overall environmental
impacts than conventional gravity
systems
May allow for regional reuse
Improved quality of effluent
discharged to environment
Increased opportunities for
effluent reuse
Possible environmental impact
during construction
Significantly reduced likelihood of
groundwater contamination
Solution would be tailored to
match local requirements
Provision of full
reticulated
sewerage
system
Local treatment
and
management
with greywater
reuse
Larger capital investment
required
Short term inconvenience for
residents during construction i.e.
noise, vehicle movement
Decreased reticulated water
demands
Improved quality of effluent
discharged to environment
Increased opportunities for
effluent reuse
Possible environmental impact
during construction
Significantly reduced likelihood of
groundwater contamination
Decreased hydraulic and
biological loads on the system
Limited additional treatment
infrastructure required
Transfer to
Narooma
system
Existing resources can be utilised
Short term inconvenience for
residents during construction i.e.
noise, vehicle movement
Improved quality of effluent
discharged to environment
Increased opportunities for
effluent reuse
Possible environmental impact
during construction
Significantly reduced likelihood of
groundwater contamination
197
Eurobodalla Integrated Water Cycle Management Strategy
9.13.4 Integrated Water Cycle Management Scenarios
Using the bundling process the above water management opportunities could be combined
into integrated scenarios. Table 9-41 presents examples of integrated scenarios.
Table 9-41 Integrated Scenarios for Mystery Bay
Minimal
Solution
Improved management of existing
on-site facilities
Traditional
Approach
Integrated Scenarios
3
"
Local treatment
and management
"
Transfer to
Kianga system
Local treatment
and management
Provision of
full
reticulated
sewerage
system
5
"
Enhanced management of
existing on-site facilities
Centralised
management
of effluent
from on-site
facilities
4
"
Local treatment
and management
with greywater
reuse
"
Transfer to
Kianga system
Minimal Improved management of existing on-site facilities.
Traditional Provision of full reticulated sewerage systems with local treatment and management.
Integrated Scenario 3 Centralised management of effluent from on-site facilities with local treatment
and management.
Integrated Scenario Enhanced management of existing on-site facilities.
Integrated Scenario 5 Provision of full reticulated sewerage systems with local treatment and
management and greywater reuse.
The TBL assessment (Table 9-42) presents the comparative environmental, social and
economic benefits of each integrated scenario example.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-42 Triple Bottom Line Assessment of Mystery Bay
Integrated Scenarios
Minimal
Solution
Traditional
Approach
3
4
5
Efficient use of fresh
water resource
0
0
0
0
2
Minimises low flow water
extractions
0
0
0
0
2
Minimises green house
gas emissions
1
1
1
2
1
Minimises pollutants
being discharged to the
aquatic environment
2
2
2
2
3
Minimises urban
stormwater volumes
0
0
0
0
0
Ensure sustainable
practices
0
0
0
0
2
Environmental Sum
3
3
3
4
10
Environmental Rank
3
3
3
2
1
Improves security of
town water supply
0
0
0
0
2
Improves the quality of
drinking water
0
0
0
0
0
Improves urban water
service levels
1
3
3
3
3
Increase public
awareness of urban
water issues
1
1
1
2
2
Minimises noncompliance to policy and
legislation
1
3
3
3
3
Protects public health
2
3
3
3
3
Social Sum
5
10
10
11
13
Social Rank
5
3
3
2
1
0.56
0.94
0.74
0.60
0.72
Financial Rank
1
4
3
2
4
TBL Score
9
10
9
6
6
TBL Rank
4
4
3
1
1
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV
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Eurobodalla Integrated Water Cycle Management Strategy
The preferred option according to the above criteria is the enhanced management of onsite systems (option 4) or local treatment and management with greywater reuse (Option5),
Option 5 ranked better in terms of social and environmental criteria, however it is more
expensive than option 4.
200
Eurobodalla Integrated Water Cycle Management Strategy
9.14 Central Tilba and Tilba Tilba
9.14.1 Background
The Village Landscape
The villages of Central Tilba and Tilba Tilba are located in the south eastern corner of the
Shire. Access to both villages is via the Princess Highway through Punkally Tilba Road and
Corkhill Drive for Central Tilba and Tilba Tilba respectively, see Figure 9-22 below.
Figure 9-22 Central Tilba and Tilba Tilba Location
Both villages are historic and central Tilba is listed by the National Trust. The land
surrounding the villages consists of the Gulaga National Park, sensitive vegetation
ecosystems and farmland. Population estimates for the village have not been prepared as
they are much smaller than the ABS collection districts. According to the 1996 land monitor
there is likely to be a land shortage in the next few years unless more land is subdivided.
Existing Water Management Systems
Central Tilba and Tilba Tilba are part of the regional water supply and sewage is treated on
site. Council’s GIS records 45 on-site treatment facilities, 62% are septic tanks with effluent
disposal by adsorption trench and an additional 13% are septic tanks with effluent pumpout. The remaining 25% are treated by aerated systems. Soil adsorption systems generally
do not comply with the performance objectives of Environmental and Health Protection
Guidelines: On-site Sewage Management for Single Households (1998)
Stormwater from these villages is released into intermittently flowing streams that form part
of the Bobundara Creek Catchment.
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Eurobodalla Integrated Water Cycle Management Strategy
9.14.2 What are the Issues?
The issues associated with the village landscape and water management system are
classified into environmental and social issues, and are discussed below. Other community
issues are not part of this study.
Environmental Issues
!
An estimated 120 kL/a of stormwater is generated in Central Tilba and Tilba Tilba,
containing 145 kg/a of nitrogen and 20kg/a of phosphorous.
!
The villages are located on granite and basalt, resulting in poor adsorption of septic
effluent.
Social Issues
!
There are potential public health risks associated with the current on-site
wastewater management systems, particularly during rainy periods.
!
At present, pump outs are causing public nuisance (odours) and disruptions.
!
The villages are historic and hence a popular tourist area. The amenity of this area
should not be diminished and as a result the community favours sewering of the
villages to maximise the economic potential of tourism.
!
The village residents do not receive water saving ‘tips’ and information on how to
better manage on-site wastewater management systems.
9.14.3 How Do We Fix the Problems?
Overview
Tilba Tilba and Central Tilba contain lots sizes that are less than the recommended size for
sustainable land application and current pump-out arrangements pose social issues. To
address the issue of effluent disposal, the village could be sewered. There is the possibility
of agricultural re-use and the level of nutrient removal required will dictate if current on-site
treatments could be conveyed from the villages, disinfected and re-used or if further off-site
treatment is required.
Water Cycle Management Opportunities
There are both short term and medium term measures to improve the water cycle
management at Central Tilba and Tilba Tilba. The short term measures could be
implemented as a matter of priority to achieve best practice standard of the medium term
opportunities.
Short Term Measures
The short term measures include:
!
Regular monitoring of the on site wastewater management systems for
performance and integrity,
!
Systematic monitoring of local waterways and urban stormwater quality and
quantity.
The above short term measures are complimentary to the proposed medium term
measures and would help Council and the community to manage their water cycle more
sustainably.
202
Eurobodalla Integrated Water Cycle Management Strategy
Medium to long Term Water Cycle Management Opportunities
Medium term opportunities are measures related to improving the long term sustainability of
the water cycle. In addition these opportunities will also reduce public health and
environmental impacts and enhance the service standards for the water services. Table
9-43 presents these opportunities along with their capital and present value at a rate of 7%.
Table 9-43 Integrated Water Cycle Management Options for Central Tilba and Tilba
Tilba
Cost Estimate
Capital ($m)
NPV @ 7% ($m)
Improved management of existing on-site facilities
0.060
0.327
Enhanced management of existing on-site
1
facilities
0.22
0.29
Centralised management of effluent from on-site
1
facilities with agricultural reuse
1.91
0.93
Provision of sewerage system with package plant
1
with agricultural reuse
1.94
0.95
Note 1: NPV’s for on-site systems are based on a rolling program commencing in 2003. NPV’s for sewering
Nelligen are based on work commencing in 2012
Improved Management of Existing On-site Wastewater Facilities
The seepage from existing on-site wastewater management systems could be reduced by
regularly emptying the contents of the septic tanks and putting monitoring systems in place
to prevent septic tank overflows and to assess the integrity of the tanks.
A single contract could be arranged by the Council or by the community such that the septic
tanks are pumped at set time intervals. This would cover both effluent and sullage
pumpout. The cost of this pumpout could be evenly split between the residents. To facilitate
pumping every tank would need to be provided with a smaller holding tank or pumpout
facility.
This opportunity would remove the issue of effluent contaminating the aquifer and
waterways, but raises community issues in relation to odour during pumpout and frequent
movement of trucks in the neighbourhood.
Enhanced Management of Existing On-site Wastewater Facilities
There are several options available to upgrade the existing on-site wastewater
management systems to achieve greater public health and environmental outcomes. The
first option is to retain the existing septic tank and upgrade the on-site effluent management
system. An example of this would be the replacement of the adsorption trenches with lined
evapotranspiration beds, which achieve a higher level of water and nutrient uptake through
plants. This however may not be a viable option in Central Tilba and Tilba Tilba due to the
step gradient of the landscape and the high percentage of rock.
Another alternative is to upgrade the septic system to one that achieves nutrient removal
and therefore results in a higher quality effluent discharge (e.g. aerated tanks). This would
increase the potential uses of the treated effluent.
Both these options would minimise the potential of environmental degradation as well as
reducing the likelihood of public health issues and odour complaints.
203
Eurobodalla Integrated Water Cycle Management Strategy
Centralised Effluent Drainage System
As an alternative to putting in a full sewerage system, the effluent from existing on-site
systems would be collected and transported to a treatment plant. The pipes used would be
smaller than the full reticulated sewerage system, because the on-site systems would
remove most of the solid material from the sewerage. Installing shallow pipes has the
added cost benefit due to the rocky nature of the ground. The treatment process proposed
is reed beds, which rely on the natural process of plants to treat the wastewater. Effluent
disposal would be through agricultural reuse.
Package Sewage Treatment Plant with Agricultural Reuse
A reticulated sewage network could be provided to the villages with treatment of the
wastewater at a centralised treatment plant located locally with the effluent being reused
opportunistically on local agricultural properties and discharged to local streams during wet
weather. A modified gravity sewage network has been costed.
The TBL assessment in Table 9-44 provides the comparative environmental and social
benefits of each water cycle management opportunity.
Table 9-44 Social and Environmental Aspects of The Medium to Long Term
Opportunities for Central Tilba and Tilba Tilba
Social
Improved management of
existing on-site facilities
Enhanced management of
existing on-site facilities
Odours associated
Improved air quality and visual
character
Potential disturbance during
construction period
Amenity of popular tourist area not
diminished
Centralised management of
effluent from on-site facilities
with agricultural reuse
Less opportunity for public nuisance
and disruptions caused by
pumpouts
Short term disruption due to
decommissioning of open trenches
and construction of centralised
system
Environmental
No discharge of septic effluent to the
environment
Further degradation of environment
halted
Decreased risk of overflows to
sensitive environments including
local waterbodies
Improved effluent quality discharged
and lessened potential impact of
overflows
Resource returned at more
beneficial stage of the water cycle
Reduced public health risk
Amenity of popular tourist area not
diminished
Provision of full reticulated
sewerage system with
package plant with agricultural
reuse
Less opportunity for public nuisance
and disruptions caused by
pumpouts
Short term disruption due to
decommissioning of open trenches
and construction of centralised
system
Decreased risk of overflows to
sensitive environments including
local waterbodies
Improved effluent quality discharged
and lessened potential impact of
overflows
Resource returned at more
beneficial stage of the water cycle
Reduced public health risk
9.14.4 Integrated Water Cycle Management Scenarios
Using the bundling process the above water management opportunities can be combined
into integrated scenarios. Table 9-45 present examples of integrated scenarios.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-45 Integrated Scenarios for Central Tilba and Tilba Tilba.
Minimal
Solution
Improved management of
existing on-site facilities
Traditional
Approach
Integrated Scenarios
3
"
Enhanced management of
existing on-site facilities
"
Centralised management of
effluent from on-site
facilities with agricultural
reuse
Provision of modified
gravity sewerage system
with package plant with
agricultural reuse
4
"
"
Minimal Improved management of existing on-site facilities.
Traditional Provision of full reticulated sewerage systems with package treatment plant and
agricultural reuse.
Integrated Scenario 3 Enhanced management of existing on-site facilities.
Integrated Scenario 4 Centralised management of effluent from on-site facilities with agricultural
reuse.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 9-46 Triple Bottom Line Assessment of Central Tilba and Tilba Tilba
Minimal
Solution
Traditional
Approach
Efficient use of fresh water
resource
0
Minimises low flow water
extractions
Integrated Scenarios
3
4
1
0
1
0
2
0
2
Minimises green house gas
emissions
1
1
2
1
Minimises pollutants being
discharged to the aquatic
environment
2
2
2
2
Minimises urban
stormwater volumes
0
0
0
0
Ensure sustainable
practices
1
2
1
2
Environmental Sum
4
8
5
8
Environmental Rank
4
1
3
1
Improves security of town
water supply
0
2
0
2
Improves the quality of
drinking water
0
0
0
0
Improves urban water
service levels
2
3
3
3
Increase public awareness
of urban water issues
1
2
2
2
Minimises non-compliance
to policy and legislation
2
3
3
3
Protects public health
2
3
3
3
Social Sum
7
13
11
13
Social Rank
4
1
3
1
0.33
0.95
0.29
0.93
Financial Rank
1
4
2
3
TBL Score
9
6
8
5
TBL Rank
4
2
3
1
ENVIRONMENTAL
SOCIAL
FINANCIAL
NPV ($m over 30 years)
According to the TBL assessment, centralised management of effluent from the existing onsite system with the incorporation of agricultural reuse is the most suitable options for Tilba
Tilba and Central Tilba.
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Eurobodalla Integrated Water Cycle Management Strategy
9.15 Akolele
9.15.1 Background
The Village Landscape
Akolele is situated on the north eastern shores of Wallaga Lake, which is at the border of
Eurobodalla and Bega Shires. Figure 9-23 shows the location of Akolele.
Figure 9-23 Akolele Topographic Map
The 1996 housing monitor recorded 19 vacant lots in Akolele. There is sufficient land
available for release to supply the predicted population growth.
Existing Water Management Systems
Akolele is connected to the Bega water supply scheme.
According to the Council’s GIS records, there are 35 on-site treatment facilities in the
village, of which 71% are septic tanks with effluent disposal by adsorption trench and an
additional 9% are septic tanks with effluent pump-out. The remaining systems utilise
aerated systems that result in higher levels of nutrient removal than septic systems.
There are 300 m of stormwater pipe recorded in the village with two discharge points to
Wallaga Lake. An estimated 130 kL/a of stormwater is generated in Akolele, containing
150kg /a of nitrogen and 20 kg/a of phosphorous.
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Eurobodalla Integrated Water Cycle Management Strategy
9.15.2 What Are the Issues?
The issues associated with the village landscape and water management system are
classified into environmental and social issues, and are discussed below. Other community
services related issues are not part of this study.
Environmental Issues
!
On-site systems may be impacting on water quality within the lake,
!
Stormwater discharges to the lake may impact on water quality.
Social Issues
!
Potential health risk associated with recreational use of lake due to seepage from
on-site systems.
9.15.3 How Do We Fix the Problems?
Overview
Water Cycle Management Opportunities
There are both short and medium term measures to improve the water cycle management
at Akolele. The short term measures should be implemented as a matter of priority to
achieve best practice standard immaterial of the medium term opportunities.
Short Term Measures
The short term measures include:
!
Improved management of existing on-site wastewater facilities,
!
Regular monitoring of the on-site wastewater management systems for
performance and integrity,
!
Systematic monitoring of local waterways and urban stormwater quality and
quantity,
!
Regular mail-outs of ways to maintain on-site wastewater systems including
information on water conservation
The above short term measures are complimentary to the proposed medium term
measures and would help Council and the community to manage their water cycle more
sustainably.
Medium to Long Term Water Cycle Management Opportunities
Council has decided that Akolele will be sewered in conjunction with the sewering of
Wallaga Lake Heights. Both towns will be connected to the Bermagui STP. As a result the
long term options for Akolele have not been investigated as part of this study.
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Eurobodalla Integrated Water Cycle Management Strategy
10 Shire Wide Integrated Water Cycle
Management Scenarios
10.1 Overview
This report has identified both immediate and short term measures together with the
medium-long term water cycle management opportunities and options at the regional and
local level. The nominated immediate measures when implemented will ensure legislative
compliance, and the short term measures will assist in future planning and in achieving best
practice management standards. Thus it is expected that Council will implement both the
immediate and short term measures as a matter of priority. The medium to long term water
cycle management options, are envisaged as meeting the long term future vision for the
Shire.
This study has identified and evaluated all the water sources options available both at the
regional and local individual town and village level, (see Appendix C on Coarse screening)
using the TBL assessment. Using the bundling process, IWCM options were then
developed incorporating the most viable opportunities at both the regional and local level.
In order to assist the Shire community in adopting the most appropriate type of water
management option to meet future needs, a number of scenarios have been developed
using the local and regional integrated options. As the management of the urban water
supply and reclaimed water is done at a regional level, it was decided during the process to
use the regional IWCM options as the basic templates for establishing the Shire wide
scenarios.
In view of the large number of towns and villages in Eurobodalla, a number of simple
decision processes were adopted, to assist with the Shire wide scenario building process.
There are nine small towns that rely on on-site sewerage systems. In considering a Shire
wide response it was necessary to rank these towns on a priority basis. The details of this
assessment are contained in Appendix X (risk assessment of villages). The assessment
identified high and low priority groups
High Priority
Low Priority
South Durras
Akolele
Nelligen
Central Tilba, Tilba Tilba
Bodalla
Mystery bay
Rosedale and Guerilla Bay
Potato Point
Congo
The current on-site wastewater management in the villages classed as high priority are
posing significant environmental, public health and social impacts.
Similarly, in order to differentiate the villages requiring improved water supply systems into
high and low priority groups, the preferences expressed by the local residents were used.
The residents at the village of Nelligen for example, indicated at the first round of
community consultation, a desire to have improved water supply management, therefore
this villages has been placed in the high priority group. The South Durras and Congo
209
Eurobodalla Integrated Water Cycle Management Strategy
villages have been placed in the low priority group, as the residents from both villages did
not rank an improved water supply as of high importance.
Urban stormwater management has also been classified into high and low priority locations.
This division is based on the type of issue and the impact it has on the environment and
community.
10.2 Scenario Building
The Table 10-1 below presents examples of Shire wide integrated scenarios, developed
using the regional integrated water cycle management options. In order to simplify the
building and assessment process the IWCM options available at each village have been
reduced to two options; improve the existing on-site water supply and wastewater
management systems or provide a reticulated water and sewerage system.
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Eurobodalla Integrated Water Cycle Management Strategy
Table 10-1 Shire Wide Integrated Water Cycle Management Scenarios
Integrated Shirewide Scenarios
0
DM + RWT +
Agri. + reuse
+ pot.
6 + EF
Substitution
7
DM + RWT +
Agri.
6
DM + RWT
5
DM + RWT
4
DM + RWT
3
DM
2
Traditional
1
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
"
Non-potable water in new
developments (dual
reticulation)
"
"
Aquifer recharge for
subsequent non-potable
water use
"
"
Limited Demand Management
Comprehensive Demand Management
Water sensitive urban design for all new
developments and 10kL rainwater tanks in
20% existing houses
Provision of reticulated water supply to high
priority villages
"
Provision of reticulated water supply to low
priority villages
"
Agriculture
Reclaimed
Water Reuse
Environmental flow
substitution
"
Southern storage for the regional scheme
(x1000ML) to meet secure yield
5.6
1.5
0.9
0.93
1.01
1.01
0.84
0
Divert Batemans Bay northern catchment
sewage to Batemans Bay STP along Spine
Road and enhance Batemans Bay STP
"
"
"
"
"
"
"
"
Divert Batemans Bay southern catchment
sewage to Tomakin STP and enhance
existing Tomakin STP capability
"
"
"
"
"
"
"
"
Enhance the existing Narooma plant’s
capability when load meets capacity
"
"
"
"
"
"
"
"
Improved management of urban stormwater
in high priority catchments
"
"
"
"
Improved management of urban stormwater
in low priority catchments
"
Retic Sge. – High Priority Villages
"
Retic Sge. – Low Priority Villages
"
Enhanced Mgmt. of on-site facilities
"
"
"
"
"
"
"
"
"
"
"
"
"
Note 1: High priority stormwater catchments are Little Lake, Joes Creek, Wimbie Creek, Batemans Bay, Short
Beach Creek, Candlagan Creek, Surf Beach, and Denhams Beach.
Note 2: Improved sewage management is the option identified by the triple bottom line assessment in the local
water strategy. This is sewering for Nelligen Rosedale, Guerilla Bay, Bodalla, Potato Point and central Tilba and
Tilba Tilba and enhanced management of on-site facilities for South Durras, Congo and Mystery Bay
211
Eurobodalla Integrated Water Cycle Management Strategy
10.2.1 Description of the Shire wide Water Cycle Management Scenarios
Traditional Scenario
!
Waterwise Education,
!
Provision of reticulated water for high priority villages
!
Provision of reticulated water for low priority villages
!
Agricultural reuse
!
Southern Dam capacity 5 600 ML,
!
Upgrade Batemans Bay transport system including bypass along Spine Road
alignment and Batemans Bay STP upgrade,
!
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and
enhance existing Tomakin STP capacity,
!
Enhance the existing Narooma STP capacity when load meets capacity,
!
Improved management of urban stormwater in high priority catchments
!
Provision of reticulated sewage for high priority villages
!
Provision of reticulated sewage for low priority villages.
Current
Extraction
(w ithout turbidity
constraints)
Traditional Scenario
Environmental
Higher Environmental
Flow Protection (95/30) Flow Protection (80/30)
9000
ML/a
8000
7000
5 600 ML Southern Dam
6000
Impact of Rainw ater Tanks
5000
Impact of pipeline upgrade
4000
Existing System
3000
Demand
2000
1000
Year
Figure 10-1 Traditonal Scenario
Integrated Scenario 1
212
!
Waterwise Education
!
Comprehensive demand management,
2032
2029
2026
2023
2020
2017
2014
2011
2008
2005
2002
0
Eurobodalla Integrated Water Cycle Management Strategy
!
Southern Dam capacity 1 500 ML,
!
Upgrade Batemans Bay transport system including bypass along Spine Road
alignment and Batemans Bay STP upgrade,
!
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and
enhance existing Tomakin STP capacity,
!
Enhance the existing Narooma STP capacity when load meets capacity,
!
Improved sewage management for villages (see note 2 above).
Current
Extraction
Environmental
(without turbidity
constraints) Flow Protection (95/30)
Higher Environmental
Flow Protection (80/30)
9000
8000
ML/a
7000
1500ML Southern dam
6000
Impact of pipeline upgrade
5000
Existing system
Demand
4000
Demand managed demand
3000
2000
1000
2032
2030
2028
2026
2024
2022
2020
2018
2016
2014
2012
2010
2008
2006
2004
2002
0
Year
Figure 10-2 Integrated Scenario 1
Integrated Scenario 2
!
Waterwise Education
!
Comprehensive demand management including water sensitive urban design for all
new developments
!
10 kL rainwater tanks in new developments and 20% of existing houses,
!
Southern Dam capacity 900 ML,
!
Upgrade Batemans Bay transport system including bypass along Spine Road
alignment and Batemans Bay STP upgrade,
!
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and
enhance existing Tomakin STP capacity,
!
Enhance the existing Narooma STP capacity when load meets capacity,
!
Provision of reticulated sewage for high priority villages
!
Enhanced management of on-site systems (see note 2 above).
213
Eurobodalla Integrated Water Cycle Management Strategy
Current Extraction
(without turbidity
constraints)
Environmental
Flow Protection (95/30)
Higher Environmental
Flow Protection (80/30)
9000
8000
900ML Southern dam
7000
Impact of rainwater tanks
ML/a
6000
Impact of pipeline upgrade
5000
Existing system
4000
Demand
3000
Demand managed demand
2000
1000
2032
2030
2028
2026
2024
2022
2020
2018
2016
2014
2012
2010
2008
2006
2004
2002
0
Year
Figure 10-3 Integrated Scenario 2
Integrated Scenario 3
214
!
Waterwise Education
!
Comprehensive demand management including water sensitive urban design for all
new developments
!
10 kL rainwater tanks in new developments and 20% of existing houses,
!
Provision of reticulated water supply to high priority villages
!
Southern Dam capacity 930 ML,
!
Upgrade Batemans Bay transport system including bypass along Spine Road
alignment and Batemans Bay STP upgrade,
!
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and
enhance existing Tomakin STP capacity,
!
Enhance the existing Narooma STP capacity when load meets capacity,
!
Provision of reticulated sewage for high priority villages
!
Enhanced management of on-site systems (see note 2 above).
Eurobodalla Integrated Water Cycle Management Strategy
Current
Extraction
(without turbidity
Environmental
constraints)
Flow Protection (95/30)
Higher Environmental
Flow Protection (80/30)
9000
8000
930ML Southern Dam
7000
Impact of rainwater tanks
ML/a
6000
Impact of pipeline upgrade
5000
Existing System
4000
Demand
3000
Demand managed demand
2000
1000
2032
2030
2028
2026
2024
2022
2020
2018
2016
2014
2012
2010
2008
2006
2004
2002
0
Year
Figure 10-4 Integrated Scenario 3
Integrated Scenario 4
!
Waterwise Education
!
Comprehensive demand management including water sensitive urban design for all
new developments
!
10 kL rainwater tanks in new developments and 20% of existing houses,
!
Provision of reticulated water supply to high priority villages,
!
Provision of reticulated water supply to low priority villages,
!
Southern Dam capacity 1 010 ML,
!
Upgrade Batemans Bay transport system including bypass along Spine Road
alignment and Batemans Bay STP upgrade,
!
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and
enhance existing Tomakin STP capacity,
!
Enhance the existing Narooma STP capacity when load meets capacity,
!
Provision of reticulated sewage for high priority villages
!
Provision of reticulated sewage for low priority villages.
215
Eurobodalla Integrated Water Cycle Management Strategy
C urrent
Extraction
Environm ental
(without turbidity
Flow Protection (95/30)
constraints)
H igher Environm ental
Flow Protection (80/30)
9000
8000
ML/a
7000
6000
1010M L Southern Dam
5000
Im pact of rainwater
tanks
Im pact of pipeline
upgrade
Existing system
4000
3000
D em and
2000
D em and m anaged
dem and
1000
2032
2030
2028
2026
2024
2022
2020
2018
2016
2014
2012
2010
2008
2006
2004
2002
0
Year
Figure 10-5 Integrated Scenario 4
Integrated Scenario 5
216
!
Waterwise Education
!
Comprehensive demand management including water sensitive urban design for all
new developments
!
10 kL rainwater tanks in new developments and 20% of existing houses,
!
Provision of reticulated water supply to high priority villages,
!
Provision of reticulated water supply to low priority villages,
!
Reclaimed water reuse for agriculture,
!
Southern Dam capacity 1 010 ML,
!
Upgrade Batemans Bay transport system including bypass along Spine Road
alignment and Batemans Bay STP upgrade,
!
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and
enhance existing Tomakin STP capacity,
!
Enhance the existing Narooma STP capacity when load meets capacity,
!
Improved management of urban stormwater in high priority catchments (see note 1
above),
!
Provision of reticulated sewage for high priority villages,
!
Provision of reticulated sewage for low priority villages.
Eurobodalla Integrated Water Cycle Management Strategy
Current
Extraction
Environmental
(without turbidity
Flow Protection (95/30)
constraints)
Higher Environmental
Flow Protection (80/30)
9000
ML/a
8000
7000
1010ML Southern dam
6000
Impact of rainwater tanks
Impact of pipeline upgrade
5000
Existing system
4000
Demand
3000
Demand managed demand
2000
1000
2032
2030
2028
2026
2024
2022
2020
2018
2016
2014
2012
2010
2008
2006
2004
2002
0
Year
Figure 10-6 Integrated Scenario 5
Integrated Scenario 6
!
Waterwise Education
!
Comprehensive demand management including water sensitive urban design for all
new developments
!
10 kL rainwater tanks in new developments and 20% of existing houses,
!
Provision of reticulated water supply to high priority villages,
!
Provision of reticulated water supply to low priority villages,
!
Reclaimed water reuse for agriculture,
!
Reclaimed water reuse for aquifer recharge for subsequent non-potable water use,
!
Reclaimed water reuse for non-potable water use in new developments (dual
reticulation),
!
Southern Dam capacity 840 ML,
!
Upgrade Batemans Bay transport system including bypass along Spine Road
alignment and Batemans Bay STP upgrade,
!
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and
enhance existing Tomakin STP capacity,
!
Enhance the existing Narooma STP capacity when load meets capacity,
!
Improved management of urban stormwater in high priority catchments (see note 1
above)
!
Provision of reticulated sewage for high priority villages
217
Eurobodalla Integrated Water Cycle Management Strategy
!
Provision of reticulated sewage for low priority villages.
Current
Extraction
(without turbidity
constraints)
Environmental
Flow Protection (95/30)
Higher Environmental
Flow Protection (80/30)
ML/a
9000
8000
840ML Southern dam
7000
Non potable urban reuse
6000
Impact of rainwater tanks
5000
Impact of pipeline upgrade
4000
Existing system
3000
Demand
2000
Demand managed demand
1000
2032
2030
2028
2026
2024
2022
2020
2018
2016
2014
2012
2010
2008
2006
2004
2002
0
Year
Figure 10-7 Integrated Scenario 6
Integrated Scenario 7
218
!
Waterwise Education
!
Comprehensive demand management including water sensitive urban design for all
new developments
!
10 kL rainwater tanks in new developments and 20% of existing houses,
!
Provision of reticulated water supply to high priority villages,
!
Provision of reticulated water supply to low priority villages,
!
Reclaimed water reuse for agriculture,
!
Reclaimed water reuse for aquifer recharge for subsequent non-potable water use,
!
Reclaimed water reuse for non-potable water use in new developments (dual
reticulation),
!
Reclaimed water reuse for environmental flow substitution,
!
Upgrade Batemans Bay transport system including bypass along Spine Road
alignment and Batemans Bay STP upgrade
!
Transfer Batemans Bay southern catchment sewerage to Tomakin STP and
enhance existing Tomakin STP capacity,
!
Enhance the existing Narooma STP capacity when load meets capacity,
!
Improved management of urban stormwater in high priority catchments (see note 1
above),
!
Improved management of urban stormwater in low priority catchments (see note 1
above),
Eurobodalla Integrated Water Cycle Management Strategy
!
Provision of reticulated sewage for high priority villages,
!
Provision of reticulated sewage for low priority villages.
In this scenario, if the demand combined to increase as projected, then the southern
storage would be required between years 2035 and 2040.
Current
Extraction
Environmental
Flow Protection (95/30)
(without turbidity
constraints)
Higher Environmental
Flow Protection (80/30)
9000
ML/a
8000
7000
Return flow substitution
6000
Non potable urban reuse
5000
Impact of rainwater tanks
4000
Impact of pipeline upgrade
3000
Existing System
2000
Demand
1000
Comprehensive Demand
Management
2032
2030
2028
2026
2024
2022
2020
2018
2016
2014
2012
2010
2008
2006
2004
2002
0
Year
Figure 10-8 Integrated Scenario 7
The above Shire wide scenarios are suggested recommendations. They may be modified to
reflect the priorities and preferences of individual communities and as the results of ongoing
investigations into the individual components of the scenarios developed become available.
Prior to the implementation of any of the recommended solutions, further consultation with
the individual village would be undertaken.
10.3 Assessment of Integrated Water Cycle Management Scenarios
The TBL assessment table below provides the comparative environmental, social and
economic perspective of each water cycle management scenario.
219
Eurobodalla Integrated Water Cycle Management Strategy
Table 10-2 TBL Assessment for Shire Wide Scenarios
Integrated Scenarios
6 + EF
Substitution
7
DM + RWT
+ Agri. +
reuse + pot.
6
DM + RWT
+ Agri.
5
DM + RWT
4
DM + RWT
3
DM + RWT
2
DM
1
Traditional
0
Ensure the efficient use of the fresh water
resource
0
1
2
2
2
3
3
3
Minimises water extractions and protects
low flows
0
1
2
2
2
3
3
3
Minimises green house gas emissions
3
3
3
2
2
1
1
1
Minimises pollutants being discharged to the
aquatic environment
1
1
1
1
1
2
2
3
Minimises urban stormwater volumes
0
0
1
1
2
2
2
3
Ensure sustainable practices
0
1
2
2
2
3
3
3
Environmental Sum
4
7
11
10
11
14
14
16
Environmental Rank
8
7
4
6
4
2
2
1
0
1
2
2
2
3
3
3
ENVIRONMENTAL
SOCIAL
Improves security of town water supply
Improves the quality of drinking water
0
0
0
2
3
3
3
3
Improves urban water service levels
1
1
2
2
3
3
3
3
Increase public awareness of urban water
issues
1
2
3
3
3
3
3
3
Minimises non-compliance to legislation
3
3
3
3
3
3
3
3
Protects public health
2
2
2
3
3
3
3
3
Social Sum
7
9
12
15
17
18
18
18
Social Rank
8
7
6
5
4
1
1
1
Water Supply
110.3
64.2
73.1
74.7
76.8
76.8
77.3
71.2
Sewerage
79.7
26.1
30.7
30.7
31.4
40.8
40.8
40.8
Stormwater
8.5
0
0
0
0
8.5
8.5
11.7
103.8
105.
4
126.6
123.
7
ECONOMIC
NPV @ 7% in $m
Sub-total
198.5
Change in the typical
residential rate bill from
the traditional scenario
90.3
108.2
126.1
Water Supply
0
-124
-144
-137
-128
-128
-122
-149
Sewerage
0
-192
-186
-186
-181
-145
-145
-145
Stormwater
0
Financial Rank
8
1
2
3
4
6
7
5
TBL Sum
24
15
12
14
12
9
10
7
TBL Rank
Savings from
Traditional Case
(NPV @ 7%)
8
7
4
6
4
2
3
1
Water Supply
0
46.1
37.2
35.6
33.5
33.5
32.9
39.1
Sewerage
0
53.6
49.0
49.0
48.3
38.9
38.9
38.9
Stormwater
0
-
-
-
-
0
0
+3.2
Based on consistently applying the TBL assessment criteria, the preferred option is
integrated scenario 7. Integrated Scenario 7 has some risks associated with its adoption.
These include:
220
!
Sustainability on environmental flow
!
Future water demands
Eurobodalla Integrated Water Cycle Management Strategy
!
Dual reticulation uptake and associated community costs
Sustainability of Environmental Flow
The water quality and dilution requirements for environmental flow substitution have not yet
been established for the Moruya River System. Further the substitution regime has not
been agreed by the Government Authorities and community. The outcome of these
negotiation and studies may or may not support the concept of environmental flow
substitution of reclaimed water. Conflict may also arise between different uses for the
reclaimed water (environmental flow substitution vs agricultural reuse) in periods of low
river flow. If environmental flow substitution of reclaimed water was not supported then
there will be a need to build the Southern dam within the 30 year timeframe. This will make
scenario 7 significantly more expensive than the other integrated scenarios altering the TBL
ranking of the scenarios in Table 10-2 and scenario 5 is the preferred option.
Future Water Demands and Dual Reticulation Uptake Levels
Figure 10-2 to Figure 10-8 illustrate how the demands will be met by different elements for
each integrated scenario. The cost implications for scenario 7 not meeting the demands
predicted by each component and the demand reduction program are greater than the
other options. This may arise for example though customer choices uptake of reclaimed
water and rainwater tanks. If there is a gap between what can be supplied from each
component and what the community requires, a dam will need to be built within the 30
years timeframe, making scenario 7 more expensive which will alter the preferred scenario
ranking.
Recommendation
Integrated Scenario 7 carries greater risks than the other options. DPWS recommends that
Council consider the adoption of Integrated Scenario 5. As recommended elsewhere in this
report, the IWCM strategy should be reviewed in 5 years. The uncertainties associated with
Integrated Scenario 7 may have been resolved by this time.
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Eurobodalla Integrated Water Cycle Management Strategy
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222
Eurobodalla Integrated Water Cycle Management Strategy
Part D
How to Deliver the Scenarios
This Part provides an overview of the delivery
timeframe and the delivery mechanisms available to
Council.
223
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224
Eurobodalla Integrated Water Cycle Management Strategy
11 Timeframe for Scenario
Implementation
The following table provides the timeframe associated with each of the Shire wide
scenarios. These timeframes were used to project the cash flow in the financial modelling.
However, the actual timeframe would depend on funding availability and extent of work
involved in the subsequent investigation, community consultation and environmental impact
assessment stages.
225
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226
Eurobodalla Integrated Water Cycle Management Strategy
2033
2032
2031
2030
2029
2028
2027
2026
2025
2024
2023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
Traditional
Regional Water Supply - Transfer Main between Moruya River and Deep Creek Dam
Regional Water Supply - Coastal Connection between Moruya and Batemans Bay
Regional Water Supply - Off-River Storage Facility
Regional Water Supply - Water Filtration Plants
Regional Water Supply - Pumping Facilities upgrade including Malua Bay pump relocation
Regional Water Supply - Improved Telemetry
Regional Water Supply - Upgrade Power Supply
Reticulated water supply to high priority village (Nelligen)
Reticulated water supply to low priority village (South Durras and Congo)
Transfer Batemans Bay Northern catchment along Spine Rd and Southern catchment to
Tomakin STP
Enhance the performance of all reticulated sewerage management systems and capacity
increase when needed (eg I/I + OHS +UV plant)
Reticulated sewerage systems for high priority villages
Bodalla
Rosedale
South Durras
Nelligen
Reticulated sewerage systems for low priority villages
Central Tilba and Tilba Tilba
Potato Point
Mystery Bay
Congo
Improved management of urban stormwater in high priority catchments
Agricultural Reuse Scheme
Investigation and land purchase
Investigation and construction
227
Eurobodalla Integrated Water Cycle Management Strategy
Regional Water Supply - Transfer Main between Moruya River and Deep
Creek Dam
Regional Water Supply - Off-River Storage and associated infrastructure
Regional Water Supply - Water Filtration Plants
Regional Water Supply - Pumping Facilities upgrade including Malua Bay
pump relocation
Regional Water Supply - Improved Telemetry
Regional Water Supply - Upgrade Power Supply
Transfer Batemans Bay Northern catchment along Spine Rd to Batemans Bay
STP and Batemans Bay Southern catchment to Tomakin STP
Enhance the performance of all reticulated sewerage management systems
(eg I/I + OHS +UV plant) and increase capacity when needed
Enhanced management of on-site systems in all unsewered villages
Investigation and land purchase
Investigation and construction
228
2033
2032
2031
2030
2029
2028
2027
2026
2025
2024
2023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
SCENARIO 1
Eurobodalla Integrated Water Cycle Management Strategy
2033
2032
2031
2030
2029
2028
2027
2026
2025
2024
2023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
SCENARIO 2
Regional Water Supply - Transfer Main between Moruya River and Deep Creek Dam
Regional Water Supply - Off-River Storage and associated infrastructure
Regional Water Supply - Water Filtration Plants
Regional Water Supply - Pumping Facilities upgrade including Malua Bay pump
relocation
Regional Water Supply - Improved Telemetry
Regional Water Supply - Upgrade Power Supply
Transfer Batemans Bay Northern catchment along Spine Rd to Batemans Bay STP
and Batemans Bay Southern catchment to Tomakin STP
Enhance the performance of all reticulated sewerage management systems (eg I/I +
OHS +UV plant) and increase capacity when needed
Enhanced management of on-site systems in unsewered villages
Reticulated sewerage systems for high priority villages
Bodalla
Rosedale
South Durras
Nelligen
229
Eurobodalla Integrated Water Cycle Management Strategy
200
3
200
4
200
5
200
6
200
7
200
8
200
9
201
0
201
1
201
2
201
3
201
4
201
5
201
6
201
7
201
8
201
9
202
0
202
1
202
2
202
3
202
4
202
5
202
6
202
7
202
8
202
9
203
0
203
1
203
2
203
3
SCENARIO 3
Regional Water Supply - Transfer Main between Moruya River and Deep Creek Dam
Regional Water Supply - Off-River Storage and associated infrastructure
Regional Water Supply - Water Filtration Plants
Regional Water Supply - Pumping Facilities upgrade including Malua Bay pump
relocation
Regional Water Supply - Improved Telemetry
Regional Water Supply - Upgrade Power Supply
Reticulated water to high priority villages (Nelligen)
Transfer Batemans Bay Northern catchment along Spine Rd to Batemans Bay STP
and Batemans Bay Southern catchment to Tomakin STP
Enhance the performance of all reticulated sewerage management systems (eg I/I +
OHS +UV plant) and increase capacity when needed
Enhanced management of on-site systems in unsewered villages
Reticulated sewerage systems for high priority villages
Bodalla
Rosedale
South Durras
Nelligen
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Eurobodalla Integrated Water Cycle Management Strategy
2032
2031
2030
2029
2028
2027
2026
2025
2024
2023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
SCENARIO 4
Regional Water Supply - Transfer Main between Moruya River and Deep Creek Dam
Regional Water Supply - Off-River Storage and associated infrastructure
Regional Water Supply - Water Filtration Plants
Regional Water Supply - Pumping Facilities upgrade including Malua Bay pump
relocation
Regional Water Supply - Improved Telemetry
Regional Water Supply - Upgrade Power Supply
Reticulated water to high priority villages (Nelligen)
Reticulated water to low priority villages (South Durras and Congo)
Transfer Batemans Bay Northern catchment along Spine Rd to Batemans Bay STP
and Batemans Bay Southern catchment to Tomakin STP
Enhance the performance of all reticulated sewerage management systems (eg I/I +
OHS +UV plant) and increase capacity when needed
Enhanced management of on-site systems in unsewered villages
Reticulated sewerage systems for high priority villages
Bodalla
Rosedale
South Durras
Nelligen
Reticulated sewerage systems for low priority villages
Central Tilba and Tilba Tilba
Potato Point
Mystery Bay
Congo
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Eurobodalla Integrated Water Cycle Management Strategy
Regional Water Supply - Transfer Main between Moruya River and Deep Creek
Dam
Regional Water Supply - Off-River Storage and associated infrastructure
Regional Water Supply - Water Filtration Plants
Regional Water Supply - Pumping Facilities upgrade including Malua Bay pump
relocation
Regional Water Supply - Improved Telemetry
Regional Water Supply - Upgrade Power Supply
Reticulated water to high priority villages (Nelligen)
Reticulated water to low priority villages (South Durras and Congo)
Transfer Batemans Bay Northern catchment along Spine Rd to Batemans Bay STP
and Batemans Bay Southern catchment to Tomakin STP
Enhance the performance of all reticulated sewerage management systems (eg I/I
+ OHS +UV plant) and increase capacity when needed
Enhanced management of on-site systems in unsewered villages
Reticulated sewerage systems for high priority villages
Bodalla
Rosedale
South Durras
Nelligen
Reticulated sewerage systems for low priority villages
Central Tilba and Tilba Tilba
Potato Point
Mystery Bay
Congo
Regional agricultural reuse scheme
Improved management of urban stormwater in high priority catchments
232
2033
2032
2031
2030
2029
2028
2027
2026
2025
2024
2023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
SCENARIO 5
Eurobodalla Integrated Water Cycle Management Strategy
2033
2032
2031
2030
2029
2028
2027
2026
2025
2024
2023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
SCENARIO 6
Regional Water Supply - Transfer Main between Moruya River and Deep Creek
Dam
Regional Water Supply - Off-River Storage and associated infrastructure
Regional Water Supply - Water Filtration Plants
Regional Water Supply - Pumping Facilities upgrade including Malua Bay pump
relocation
Regional Water Supply - Improved Telemetry
Regional Water Supply - Upgrade Power Supply
Reticulated water to high priority villages (Nelligen)
Reticulated water to low priority villages (South Durras and Congo)
Transfer Batemans Bay Northern catchment along Spine Rd to Batemans Bay STP
and Batemans Bay Southern catchment to Tomakin STP
Enhance the performance of all reticulated sewerage management systems (eg I/I
+ OHS +UV plant) and increase capacity when needed
Enhanced management of on-site systems in unsewered villages
Reticulated sewerage systems for high priority villages
Bodalla
Rosedale
South Durras
Nelligen
Reticulated sewerage systems for low priority villages
Central Tilba and Tilba Tilba
Potato Point
Mystery Bay
Congo
Regional agricultural reuse scheme
Non-potable reclaimed water in new developments
Improved management of urban stormwater in high priority catchments
233
Eurobodalla Integrated Water Cycle Management Strategy
Regional Water Supply - Transfer Main between Moruya River and Deep Creek
Dam
Regional Water Supply - Water Filtration Plants
Regional Water Supply - Pumping Facilities upgrade including Malua Bay pump
relocation
Regional Water Supply - Improved Telemetry
Regional Water Supply - Upgrade Power Supply
Regional Water Supply – Environmental flow substitution
Reticulated water to high priority villages (Nelligen)
Reticulated water to low priority villages (South Durras and Congo)
Transfer Batemans Bay Northern catchment along Spine Rd to Batemans Bay STP
and Batemans Bay Southern catchment to Tomakin STP
Enhance the performance of all reticulated sewerage management systems (eg I/I
+ OHS +UV plant) and increase capacity when needed
Enhanced management of on-site systems in unsewered villages
Reticulated sewerage systems for high priority villages
Bodalla
Rosedale
South Durras
Nelligen
Reticulated sewerage systems for low priority villages
Central Tilba and Tilba Tilba
Potato Point
Mystery Bay
Congo
Regional agricultural reuse scheme
Non-potable reclaimed water in new developments
Improved management of urban stormwater in high priority catchments
234
2033
2032
2031
2030
2029
2028
2027
2026
2025
2024
2023
2022
2021
2020
2019
2018
2017
2016
2015
2014
2013
2012
2011
2010
2009
2008
2007
2006
2005
2004
2003
SCENARIO 7
Eurobodalla Integrated Water Cycle Management Strategy
12 Management and Procurement
Methods
12.1 Management Methods
Council has three basic options for managing the water services in the future. These
options are discussed below. The three figures below provide the various tasks Council or
the service provider would have to undertake for each management option.
Management Option 1 – This is the traditional approach and is similar to the current
practice. In this option, Council continues to own, fund and operate the water services
using its internal resources as appropriate.
MANAGEMENT OPTION 1
COUNCIL OWNED, FUNDED & OPERATED
Operations Planning
-Implementation Plan
- House keeping KPI’s
Environmental
Impact Assessment
(New Works)
Design &
Documentation
(New Works)
Construction
of
New Works
Operations
Management
- Compliance
Reporting
Figure 12-1 Management Option 1
Management Option 2 – In this option Council owns and funds the water services, but the
day to day operation and maintenance is managed by a private Contractor or service
provider over a set period for a pre-determined annual payment. At the end of the set
period the contract is either renewed or terminated and the business transferred to Council
on pre-determined terms and conditions.
BUSINESS
STRATEGY
- Objectives
- Strategic
- KPI’s
IWCM
STRATEGY
- Structural
Solutions
- Non-built
Solutions
PROCUREMENT
& FUNDING PLAN
- Private vs Public
- Sources of funds
COUNCIL OWNED & FUNDED WITH OPERATION OUTSOURCED TO PRIVATE SECTOR
Environ.
Impact
Assessment
(New Works)
Design &
Construction
Documentation
Of
(New Works)
New Works
Due
Diligence
Analysis of
Business
Operations
Planning
-Implementation
Plan
-House keeping
KPI’s
Operations
Management
- Compliance
- Reporting
Figure 12-2 Management Option 2
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Eurobodalla Integrated Water Cycle Management Strategy
Management Option 3 – In this option the water service business along with the existing
and new water services assets and resources is transferred to a private Contractor or
service provider. The Contractor owns, operates and funds the services over a set period
for a pre-determined annual payment. Similar to option 2, at the end of the set period the
contract is either renewed or terminated.
MANAGEMENT OPTION 3
PRIVATELY OWNED, FUNDED & OPERATED OVER A SET PERIOD (NEW&OLD FACILITIES)
Contract
Documentation
(For Whole
Business)
Due
Diligence
Analysis of
Business
Operations Planning
Environ.
-Implementation Plan
Impact
-House keeping KPI’s
Assessment
(New Works) Design & Construction
Of New Works
Operations
Management
- Compliance
Reporting
Figure 12-3 Management Option 3
Assessing the costs benefits and risks associated with each of these management options is outside the scope of
this report.
12.2 Procurement Methods
In both management options 2 and 3, the new assets and required funds could be procured
in a number of ways other than the present method of procurement. Identifying these
alternative procurement options and assessing their associated costs, benefits and risks
are beyond the scope of this study.
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Eurobodalla Integrated Water Cycle Management Strategy
Part E
How Do We Know
the Issues Are Fixed?
This Part provides an overview of the benefits achieved by
the IWCM process and how Council could sustain and
realise these benefits.
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Eurobodalla Integrated Water Cycle Management Strategy
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Eurobodalla Integrated Water Cycle Management Strategy
13 Overview
This section is concerned with answering the final of the three fundamental questions in the
IWCM process, ‘how do we know the issue is fixed?’.
An answer to this question is timeframe dependent. This strategy provides IWCM options
for addressing both the immediate and the long term water resource issues in Eurobodalla
at the regional, local and Shire wide level. It is important that the timeframe reflect both the
short term and long term vision of the Shire. In order to evaluate whether the issues specific
to Eurobodalla have been addressed and whether the resource use is optimised based on
social, economic and environmental objectives, it is important to appreciate the study
outcomes. This we believe would give the water utilities a baseline to benchmark future
reviews and to assist in the journey towards achieving sustainable IWCM. It is envisaged
that follow-up assessment and review of this strategy will be undertaken at regular intervals
of around 5 years.
13.1 Study Outcomes
The Eurobodalla’s IWCM strategy has looked at all water resources in the Shire. The IWCM
approach has delivered significant benefits to the community, ESC, the State government
and the environmental as demonstrated in the recommended solutions developed in this
strategy. These benefits are discussed with respect to the triple bottom line outcomes.
13.1.1 Economic Outcomes
The IWCM planning process for Eurobodalla has revealed potential savings to the Shire
and the state government of about $25M in infrastructure investment costs. This has been
achieved by ‘right’ sizing and optimising the infrastructure capacity, through the use of;
!
Linked climate corrected demand tracking,
!
Demand and wastewater forecasting and water services system models,
!
Innovative tenement and water use category data capture systems, and
!
Improved process designs.
Through utilising IWCM principles, this study has shown that the northern reclaimed water
reuse scheme is viable, with potential savings of $15M in pipeline and pumping costs and a
further $6M through the use of a scheme optimisation process. Initiating the northern
reclaimed water reuse scheme will transfer what has traditionally been considered waste
into a valuable resource. This will not only result in cost savings for the Shire community,
but will assist in the development of a sustainable agricultural industry. Further, the savings
achieved from the pipeline, could potentially be used to implement the optimised southern
reclaimed water reuse scheme. The optimisation of the southern reuse scheme is expected
to result in a potential saving of $10M.
The implementation of the reuse schemes would reduce extraction volumes and may
therefore allow for water trading to occur in the future. This may place Council in a position
to purchase some or all of these unused agricultural water entitlements and increase the
town’s share of the harvestable water from the Moruya and Tuross River catchments.
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Eurobodalla Integrated Water Cycle Management Strategy
Taking into account all water resources through the IWCM planning process, this study has
uncovered significant savings in capital expenditure through the downsizing and/or
deferment of infrastructure projects. Integrated option 7 for example utilises demand
management, rainwater tanks and environmental flow substitution to meet the predicted
water needs for the next 30 years without the necessity of the southern dam. The capture
of water at the point of use together with the proposed demand management program will
provide up to 25% savings in water services operating costs depending on the integrated
option adopted. The downsizing and deferment of capital costs also results in about $20M
savings in operating and maintenance costs over the 30 years. The greater the integration
of the water sources, equates to greater operating cost savings. For instance the maximum
integrated option (Scenario 7) is about 38% cheaper in terms of present value than the
traditional solution. Moreover Scenario 7 delivers significantly more environmental, social
and resource sustainability benefits.
The table below presents the savings achieved by each shire-wide integrated scenario
against the traditional solution.
6 + EF
Substitution
7
DM + RWT
+ Agri. +
reuse + pot.
6
DM + RWT
+ Agri.
5
DM + RWT
4
DM + RWT
3
DM + RWT
2
DM
Savings
from
Traditional
Case (PV
@ 7%)
Integrated Scenarios
1
Traditional
0
Water
Supply
0
46.1
37.2
35.6
33.5
33.5
32.9
39.1
Sewerage
0
53.6
49.0
49.0
48.3
38.9
38.9
38.9
Stormwater
0
-
-
-
-
0
0
+3.2
13.1.2 Environmental Outcomes
The integrated water cycle management planning process for Eurobodalla has delivered
the following benefit to the local environment. Further the strategies contained in this study
will also achieve a number of catchment management objectives over the long term.
240
!
A reduction in the amount of water drawn for urban supply from the Shire’s rivers
through demand management measures and use of rainwater tanks.
!
Better protection of low flows and preservation of natural flow patterns leading to
improved environmental water quality and improved aquatic habitat conditions.
!
A reduction in future water storage requirements needed to provide the higher level
of low-flow protection.
!
Reduced pollution of the waterways and coastal lakes through improved
wastewater and stormwater management, sewage pump station and treatment
plant upgrades.
!
Reduced effluent discharges to waterways through the reductions in urban water
use, stormwater inflow and groundwater infiltration, and the development of water
reuse systems.
!
Improved recreational water quality in the Shire’s waterways, particularly during
holiday season and dry weather periods.
!
Reduced stormwater quantity and quality discharges due to source control measure
rather than end-of-pipe control measures.
Eurobodalla Integrated Water Cycle Management Strategy
!
Improved management of existing on-site wastewater systems in the villages
resulting in lower environmental public health risk and improved sustainability of
local aquifers.
!
Reduces greenhouse gas emissions and energy consumption.
!
Streamlined subsequent facility specific environmental impact assessments,
reducing study times and costs.
13.1.3 Social Outcomes
The IWCM process and the water cycle management options contained in this strategy will
deliver the following social outcomes.
!
Reduced costs for village schemes through improved management of existing onsite systems, and through supplementation rather than replacement of existing
water supply and wastewater infrastructure.
!
Improved water supply drought security and reliability of supply through increased
delivery capacity and faster refilling of the Deep Creek storage.
!
Improved water quality and public health protection for regional water supply
consumers through the construction of water filtration plants.
!
Existing deficiencies in the levels of service to consumers have been addressed.
!
In some integrated options there is an opportunity for further savings by deferring
the need for a southern dam beyond the adopted 30 year planning horizon by using
reclaimed water to meet environmental flow needs.
!
Provision of backyard supply sources provides customer with supply source choice
and an appreciation of their water use pattern resulting in lower water use in the
long term.
!
The comprehensive demand management program in addition to delivering savings
in water bills will also result in electricity savings.
!
Integrated solutions that closely match community wants and expectations.
13.2 How to Realise and Sustain the Outcomes
Sustaining the outcomes of this study requires both structural and non-structural solutions.
The structural solutions refer to physical assets and the non-structural solutions encompass
the internal processes that support and monitor the performance of the water utility
business and its assets. This study has identified that many of Council’s internal process
are either absent or are lacking in clarity and detail. One important outcome from the
development of this study has been the implementation of simple frameworks and systems
to capture data and information. For example linking meter readings to the GIS has allowed
easy evaluation of the quantity of water used within the Shire.
It is important that these frameworks and systems be further developed, adequately
resourced and kept up to date, such that future assessment and review of this strategy can
be undertaken at minimal cost and timeframe. Capturing data and information in a
systematic way is also essential in determining how effective the adopted integrated options
are performing, and an important step in assessing whether the identified issues in
Eurobodalla are fixed.
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Eurobodalla Integrated Water Cycle Management Strategy
Reducing water usage can be achieved through applying structural solutions such as the
installation of more water efficient fixtures and appliances. While these may decrease the
flow rate of water, they may not necessarily result in reduced water use. Behavioural and
cultural aspects also form an important component of water consumption. These are
primarily addressed through the provision of education and information to the community.
Therefore, a successful program to reduce water usage needs to incorporate both
structural and non-structural solutions.
Ongoing monitoring systems need to be developed to ensure that initiatives such as
demand management are achieving their intended goals and should form a fundamental
component in assessing whether those issues identified for the Eurobodalla Shire have
been addressed. Data and information gathered through appropriate on-going monitoring
systems can then be feed back into the education campaign to form a continued refinement
of this process.
Another important factor in ensuring that the outcomes from this IWCM strategy are
sustained is to monitor the volume of bulk water production lost through the distribution
system. This IWCM strategy has devised a two stage approach to reducing the amount of
water lost. The accurate determination of unaccounted for water through additional
metering has been identified as the first important step, prior to the implementation of the
loss reduction program.
An additional aspect to consider in managing the urban water cycle of Eurobodalla in a
sustainable manner is to establish a common water cycle fund. This would allow Council to
offer choices of price paths for its customers to achieve differing levels of integration.
Although, the current legislative arrangements do not allow this to occur, it is strongly
recommended that Council and DLWC pursue this further, as a common water cycle fund
provides Council the flexibility and opportunity to signal its customers the expected
outcomes.
13.3 Strategy Review Cycle
Although, this strategy has been developed for a planning period of 30 years, it is
recommended that the plan be regularly reviewed. The recommended review interval is five
years but not greater than 10 years.
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Eurobodalla Integrated Water Cycle Management Strategy
14 Bibliography
Australian Bureau of Statistics (2001) 2001 Census
Australian Greenhouse Office (2001), Good Residential Design Guide – Your Home
Technical Manual.
Coombes, Argue and Kuczera (2000), Figtree Place: A Case Study in Water Sensitive
Urban Development.
Coombes, Kuczera and Kalma (2000), Economic, Water Quantity and Quality Results from
a House with a Rainwater Tank in the Inner City.
EPA (1999) Water Quality and River Flow Interim Environmental Objectives – Clyde River
and Jervis bay Catchments.
EPA (1999) Water Quality and River Flow Interim Environmental Objectives – Moruya River
Catchment.
EPA (1999) Water Quality and River Flow Interim Environmental Objectives – Tuross River
Catchment.
Eurobodalla Shire Council, (1998), Population Profile Eurobodalla Shire.
Department of Local Government, EPA, NSW Health, DLWC, DUAP (1998) Environment
and Health Protection Guidelines – On-site Sewage Management for Single Households
Healthy Rivers Commission, (2002) Independent Inquiry into Coastal Lakes
K.G. Macoun and Associates Pty Limited, (1999) Eurobodalla Shire Council – Eurobodalla
Water Supply Augmentation Water Demand Projections to 2021.
NHMRC/ARMCANZ (2001) Australian Drinking Water Guidelines
NHMRC/ARMCANZ/ANZECC (2000) National Water Quality Management Strategy –
Guidelines for Sewerage Systems Use of Reclaimed Water.
NSW Agriculture, Organic Waste and Recycling Unit, (1998) Eurobodalla Shirewide Effluent
and Biosolids Management Scheme.
NSW Department of Public Works and Services, (1998) Deep Creek Dam – Feasibility
Study to Increase Dam Capacity.
NSW DLWC and Local Government and Shires Association of NSW, (2002) NSW Water
Supply and Sewerage Performance Comparisons.
NSW DUAP (2001) Sustainable Urban Settlement Guidelines for Regional NSW
NSW DUAP (1997), Lower South Coast Land and Housing Monitor.
NSW DUAP (1997), Lower South Coast Regional Settlement Strategy.
NSW Government (1991), Water Supply and Sewerage Management Guidelines.
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Eurobodalla Integrated Water Cycle Management Strategy
NSW Health (2000) Greywater Reuse in Sewered Single Domestic Premises.
NSW Water Resources Council (1994) Groundwater – NSW South East Region Water
Management Strategy, Water Planning for the Future.
Public works (1993) Urban Residential Reuse Guidelines
SKP (1976)
Sinclair Knight Merz (1998) Eurobodalla Shire Council Amplification and Upgrade of
Batemans Bay Sewage Treatment Plant Concept Design.
South East Water
http://www.sewl.com.au/downloads/corporate_brochures/WaterSavers_3rd_Quarter_02.pdf
Sydney Water Corporation
http://www.sydneywater.com.au/everydropcounts/garden/rainwater_tanks_rebates.cfm,
City Rainwater Tanks http://www.cityrainwatertanks.com.au/html/roundpricelist.html,
ActewAGL http://www.actewagl.com.au/environment/rainwater.cfm,
244