Waterways and wetlands
Perth-Peel regional water plan background paper
Waterways and wetlands
Perth-Peel regional water plan background paper
Looking after all our water needs
Department of Water
September 2009
Department of Water
168 St Georges Terrace
Perth Western Australia 6000
Telephone
+61 8 6364 7600
Facsimile
+61 8 6364 7601
www.water.wa.gov.au
© Government of Western Australia 2009
September 2009
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978-1-921637-88-9 (online)
Contents
Summary .................................................................................................................... iv
1 Introduction..............................................................................................................1
1.1
1.2
1.3
Waterway and wetland values .......................................................................................... 1
Management responsibilities ............................................................................................ 2
Values under pressure...................................................................................................... 2
2 Moore-Hill river basin ..............................................................................................5
3 Swan coastal basin .................................................................................................6
3.1
1.4
1.5
Swan-Canning conditions ................................................................................................. 6
Gnangara and Jandakot mounds ..................................................................................... 8
Salinity ............................................................................................................................ 10
2 Murray River basin ................................................................................................12
2.1
2.2
2.3
2.4
Values and conditions..................................................................................................... 12
Water quality improvement plan ..................................................................................... 13
Drainage and stormwater planning ................................................................................. 15
Peel-Harvey system governance .................................................................................... 16
3 Waterways and wetlands as ecological linkages...................................................17
4 Climate change .....................................................................................................21
4.1
4.2
Potential impacts ............................................................................................................ 21
Ecological water needs................................................................................................... 22
Appendices................................................................................................................23
Appendix 1 — Existing programs............................................................................................. 23
Appendix B — significant waterways and wetlands ................................................................. 25
Shortened forms ........................................................................................................28
References ................................................................................................................30
Department of Water
iii
Summary
The Perth-Peel regional water plan (PPRWP) will provide strategic directions for sustainable
water management in the region to the year 20301. Figure 1 displays the Perth-Peel region’s
boundaries including its three subregions: Gingin, Perth and Peel.
Figure 1 Perth-Peel regional water plan boundary
This background paper provides an overview of the condition of waterways in the Perth-Peel
region, the pressures they are experiencing, key management programs and additional
needs. It is one of four background papers prepared in support of the Perth-Peel strategic
directions discussion paper released by the Department of Water in March 2009.
The four Department of Water background papers are:
1
2
3
4
1
Water efficiency, recycling and alternative water supplies
Waterways and wetlands
Climate change, water demand and water availability scenarios to 2030
Land and water planning
Water resources in this context do not include marine waters.
____________________________________________________________________________________________________________
iv
Department of Water
1
Introduction
1.1
Waterway and wetland values
A waterway can be a creek, brook, river or stream, and include a lake, estuary or inlet at its
base. Waterways also include floodplains and wetland systems that overflow into rivers, as
well as any lakes or swamps that are filled (mainly) by streams rather than shallow
groundwater. Wetlands not only include lakes with open water but areas of seasonally,
intermittently or permanently waterlogged soil. Approximately 25 per cent of the Swan
coastal plain between Moore River and Mandurah is classified as wetland (WRC 2001).
The region’s waterways and wetlands are valuable natural assets because they provide
habitat for aquatic and terrestrial flora and fauna, and support biodiversity and threatened
species. They drain land, transport and store water, and carry flood waters. Wetlands
influence the water quality of rivers and streams by removing pollutants such as sediments,
nutrients, organic and inorganic matter and some pathogens.
Many of the region’s waterways and wetlands are recognised at regional, state and national
levels for their ecological values, such as providing breeding grounds for migratory
waterbirds. The Thomsons and Forrestdale lakes and the Peel–Yalgorup system are listed
for protection under the Ramsar Convention on Wetlands of International Importance.
The region’s waterways are also valuable tourism assets and prized recreational areas. They
provide a source of water for drinking, fisheries, agriculture, mining and other industries. A
recent study estimated the private-sector value attached to the Peel Inlet and Harvey Estuary
at a net present value of $5200–$19 930 million (ECS 2008).
Waterways and wetlands support many in situ social values including:
•
recreation
•
cultural and heritage (Aboriginal and non-Aboriginal)
•
landscape and aesthetic
•
educational and scientific.
Waterways and wetlands are important components of the state’s cultural landscapes2.
George Seddon popularised the concept of ‘sense of place’ in his discourse about the Swan
coastal plain (Seddon 1971). Natural landscapes and places are locations filled with history,
memories, and emotional and symbolic meanings (Williams & Vaske 2003). The region’s
water landscapes play an important role in the customs and spiritual beliefs of the Nyungar
people. The landscapes are of cultural value through a spiritual or heritage connection
stemming from knowledge of their ancestors using and living in these places (Estill &
Associates 2005).
Some waterways, such as the Swan River and the Peel-Harvey estuarine system, have
iconic status as ‘special places’ within the region. The planned creation of the Swan Canning
Riverpark under the new Swan and Canning Rivers Management Act 2006 (WA) and the
Peel Regional Park (Peel Inlet, Harvey Estuary and the lower parts of the Murray, Serpentine
and Harvey rivers) recognises how highly the community values these waterways and their
contribution to the region’s landscape.
2
The concept of cultural landscapes integrates, for any one place, aspects of natural, Indigenous and historic,
aesthetic, scientific and social heritage values (Jane Lennon & Associates 2001).
Department of Water
1
1.2
Management responsibilities
The Department of Water is the lead organisation ensuring the management of waterways
through its Waterways Program. The Department of Environment and Conservation (DEC) is
directly responsible for the management of wetlands. However, the Department of Water
must also consider wetlands management as part of its responsibilities for the maintenance
of aquatic ecosystems and water-dependent terrestrial ecosystems. The Swan River Trust
(SRT) is responsible for management programs and projects to address threats to the
ecological health and community benefit of the Swan-Canning river system.
The Environmental Protection Authority (EPA) assesses proposed actions that may have a
significant environmental impact on wetlands and waterways. Some of the proposals it has
assessed in relation to wetlands and waterways include estuarine marinas and urban
development projects in catchments on the Swan coastal plain.
Environmental protection policies of relevance to particular waterways and waterway
catchments in the Perth-Peel region are:
•
Environmental Protection (Swan and Canning Rivers) Policy 1998
•
Environmental Protection (Peel Inlet–Harvey Estuary) Policy 1992
•
Environmental Protection (Swan Coastal Plain Lakes) Policy 1992
•
Draft Environmental Protection (Swan Coastal Plain Wetlands) Policy 2004
Natural resource management (NRM) councils also play a significant role in waterways and
wetland management. The Perth-Peel region falls within the areas of three catchment
councils: the Northern Agricultural Catchment Council (Moore-Hill river basin), the Perth
Region NRM (formerly the Swan Catchment Council) and the South West Catchments
Council (includes the Peel-Harvey Catchment Council). In terms of water resources, the
NRM groups focus on waterway health: developing river action plans, undertaking on-theground riparian management, and building capacity. The councils facilitate community and
government partnerships and coordinate implementation of state and federal NRM policies
and programs in the region.
Both the Department of Water and DEC are members of the three NRM regional councils.
Western Australia’s implementation plan for the National Water Initiative (NWI) indicates that
the state ‘is actively working to strengthen integration between regional level NRM and water
planning and management, including enhancing regional level coordination and
implementation capacity’ (Government of WA 2007).
A summary of the variety of wetlands and waterway programs being undertaken in the PerthPeel region is contained in Appendix A.
1.3
Values under pressure
Within the Perth-Peel region, many waterways and wetlands have already experienced
significant modification and degradation due to human activities such as water storages,
agriculture, land clearing, urban and industrial land uses, recreation and tourism. The human
pressures placed on waterways and wetlands can have dramatic consequences that are
difficult to reverse, such as eutrophication, sedimentation, salinisation and acidification
(Figure 2).
2
Department of Water
Pressures on water resources
Change in climate or
rainfall pattern
Nutrient input
Water storages
Livestock grazing
Vegetation clearing
Water extraction
Channel excavation
Pollutant input
Overuse
Acid sulfate soils
Irrigation
Artificial drainage
Mine dewatering
Water interception
Exotic species
Fire
Filling
Sprays
Effects on resource conditions
Altered streamflow regimes
Erosion and sedimentation
Stream or groundwater salinisation
Declining water quality
Lowered watertables
Altered stream processes
Eutrophication
Increased algal blooms
Filled or stagnated river pools
Acidification
Blockage to fish passage
Weed infestation
Ecosystem fragmentation
Increase in disease and
mosquitoes
Fish and invertebrate deaths
Figure 2 Relationship between water resource pressures and conditions
More recently, a decline in rainfall and the prospect of greater climate change have emerged
as significant pressures on water resources in the region. The declining condition of these
resources threatens the many environmental, social and economic values they support.
The Australian Government’s Coastal Catchments Initiative (CCI) has identified the SwanCanning and Peel-Harvey catchments as water quality ‘hot spots’. Unfortunately, the
pressures on the region’s waterways and wetlands are likely to increase with urban growth
and further climate change.
The health of many aquatic ecosystems, such as rivers and estuaries, is inextricably linked to
the abundance and health of the wetlands in their catchments. It is estimated that 80 per cent
of wetlands on the Swan coastal plain have been lost (EPA 2004b). Of the remainder, only
an estimated 15 per cent retain high ecological values (WRC 2001). Many of the remaining
wetlands on the Swan coastal plain have been modified to such an extent that their
ecological functions bear little resemblance to their original state (EPA 2004b).
Nutrients from urban stormwater and horticultural activities have disturbed the natural
nutrient cycle in many wetlands. This nutrient enrichment can lead to water quality problems
such as blue-green algal (cyanobacterial) blooms and increased numbers of midges and
mosquitoes. Eutrophication, inundation of wetland vegetation, introduced fauna and weeds
are widespread. Where vegetation corridors between wetlands and other native vegetation
have been reduced and fragmented, further threats to ecosystem processes at the whole
Department of Water
3
system level occur (EPA 2004b). Increasing development pressure in low-lying swampy
areas with sulfide-rich peat soils heightens the likelihood of acid sulfate soil problems3.
The region is part of one of the world’s 34 biodiversity hot spots (EPA 2007b). Many of the
pressures on water resources (i.e. habitat loss and modification due to land practices,
introduced species and climate change) are also threatening associated biodiversity values.
Appendix B provides a brief overview of EPA guidance on wetland and waterway
significance and key policy positions.
3
4
Soils containing significant levels of iron sulfide minerals pose a significant risk if oxidised when disturbed by
drainage, dewatering or soil excavation. Potential impacts include: contamination of surface water and
groundwater resources by acids, arsenic, heavy metals and other contaminants; increased mosquito
breeding; fish kills; and loss of biodiversity in wetlands and waterways (Appleyard et al. 2006).
Department of Water
2
Moore-Hill river basin
The Perth-Peel regional water plan study area includes parts of three river basins: the
Moore-Hill river basin in the north, the Swan coastal basin in the central area and the Murray
River basin in the south. Each basin extends well beyond the eastern boundary of the plan
area.
The portion of the Moore-Hill river basin within the Perth-Peel region includes part of the
Moore River plus Gingin Brook and Lennard Brook. The catchment has been extensively
cleared (>50 per cent) for agriculture. There are land-use pressures due to diversification in
horticulture and silviculture and population pressures in the coastal towns of Guilderton and
Lancelin (NACC 2005).
This portion of the basin contains poor sandy soils that allow nutrients from agricultural
activities to absorb readily, making waterways and wetlands vulnerable to eutrophication.
Gingin Brook contributes very high levels of nutrients to the Moore estuary, mainly from
fertilisers (NACC 2005).
Despite widespread land clearing, narrow bands of native vegetation remain along
waterways, but the extent of riparian vegetation surrounding wetlands is largely unknown.
Vegetation has been damaged by salinisation, waterlogging, grazing and trampling by
domestic and feral animals and invasion by weeds. A network of levees constructed to
prevent flooding of agricultural and semi-rural properties has modified the functioning of the
Moore River floodplain.
The Moore River is saline because its catchment stretches inland to low-rainfall areas that
have salt-lake systems. Gingin Brook, which enters the Moore about 10 km from the coast,
has year-round flow for most of its length due to freshwater springs and groundwater
seepage (Mayer et al. 2005). Both Lennard Brook and Gingin Brook (at Gingin) are fresh.
A rapid catchment appraisal (Alderman & Clarke 2003) of the Moore River and Gingin Brook
reported the following conditions:
•
Bank erosion is severe and extensive on the Moore River with most pools now filled
with sediment.
•
The old drainage line of the river may no longer be large enough or strong enough to
contain the energy of floodwaters because there is:
− a greater volume of water flowing off the catchment due to clearing
− a reduction in the dissipation of the energy of floodwaters due to less fringing
vegetation along the river
− prevention of water dispersal over the floodplains by levee banks.
•
Stock has direct access to a large proportion of the river foreshore and septic tanks
are used along both waterways.
•
Indicative of high levels of nitrogen, algal mats are often observed in the estuary
during summer months.
•
Groundwater in the area contains elevated nutrients.
Department of Water
5
3
Swan coastal basin
The Swan-Avon river basin covers about 128 200 km2, stretching 500 km inland from the
Indian Ocean. While it is technically a single river basin, it is often referred to as two: the
Swan basin and the Avon basin. The Avon River is officially renamed the Swan River below
Wooroloo Brook.
The Swan basin covers an area of 2126 km2. Land uses within the catchment range from
agricultural to urban, including the Perth metropolitan area. The Swan River’s main tributary
is the Canning River, which flows from the Darling Range and enters the Swan River at
Melville Water between the suburbs of South Perth and Applecross.
3.1
Swan-Canning conditions
High levels of nutrients are a priority environmental issue for the entire Swan River, as well
as the middle and upper Canning River (SRT 2006). Other significant environmental issues
affecting water quality in the Swan-Canning river system are altered and reduced river flows,
loss of fringing vegetation, erosion and sedimentation and acidification. Flows into the Swan
and Canning rivers have reduced as a result of a drying climate and the damming of major
tributaries. Improved river flows are critical to reduce the impact of sedimentation from urban
development and cleared rural catchments (SRT 2007).
There are elevated bacterial levels in the upper Swan and Canning estuaries. A key source
of contamination is stormwater entering the rivers from drains. Stormwater needs to be
redirected from discharging directly into the estuaries to improve the bacterial quality of the
water.
The Swan-Canning Cleanup Program monitors nutrient levels in 15 of the 31 subcatchments.
In these subcatchments, the total nitrogen (TN) and total phosphorous (TP) levels of the
Swan-Canning tributaries have consistently fallen since 2003. All have met short-term TN
targets since 2003 and over half (53 per cent) have met the long-term targets (i.e. a six per
cent improvement since 2003). All monitored tributaries have met the short-term TP target,
with the exception of Ellen Brook. Seventy-three per cent of tributaries have met the longterm TP target, but no improvement has been made since 2003 (SRT 2007).
Non-nutrient contaminants such as heavy metals, pesticides and herbicides also affect the
Swan-Canning rivers. Leaking underground storage tanks at petrol stations are a widespread
threat to groundwater, and contamination may eventually reach the Swan-Canning (EPA
2007b). Cumulatively, small- to medium-size enterprises (SMEs) remain one of the biggest
sources of contamination but are almost entirely unregulated (SCC 2004).
The SRT summarises the health of the Swan-Canning river system as follows:
6
•
Ecosystem health: the lower Swan estuary is good, the middle Canning estuary is
fair, the middle Swan estuary is poor, and the upper Swan estuary and upper
Canning estuary are seasonally very poor.
•
Fish: there are limited data on contaminant levels in fish, but available information
indicates that fish caught in the Swan-Canning river system are generally safe to eat.
•
Recreation and aesthetics: the waters of the lower Swan estuary and middle Canning
estuary are generally of good quality, the middle Swan estuary is generally of
moderate quality and the upper Swan estuary and upper Canning estuary are of
seasonally poor quality.
Department of Water
The SRT’s Healthy Rivers Program is the second phase of the Swan-Canning Cleanup
Program. The Healthy Rivers action plan (SRT 2007) aims to maximise the reduction of
nutrients and other contaminants entering the rivers by directing funding to catchments that
contribute the greatest amount of nutrients or other contaminants to the rivers. Where
catchment management plans do not exist, water quality improvement plans will be
developed to deliver river-health outcomes. Initial investment will focus on the priority areas
of Ellen Brook, Mills Street Main Drain and Southern River (Figure 3), with the overall aim of
reducing nutrient inputs to priority catchments by 30 per cent by 2015. Ellen Brook has the
highest median TN and TP concentrations of the monitored catchments. The SRT recently
released a Swan-Canning water quality improvement plan (SRT 2009).
Figure 3
Priority catchments of the Swan-Canning river system (SRT 2007)
Department of Water
7
3.2
Gnangara and Jandakot mounds
Water levels in shallow groundwater systems are generally declining across the Gnangara
Mound (Figure 4). Regionally the climate is becoming drier; reducing recharge and leading to
lower groundwater levels. Superimposed on this regional trend are the effects of localised
land use, vegetation, urbanisation and groundwater abstraction (McHugh & Bourke 2008).
Figure 4 Watertable decline on the Gnangara Mound between 1979 and 2003 (McHugh &
Bourke 2008)
The superficial aquifer of the Gnangara Mound supports numerous ecosystems, including
permanent and seasonal wetlands, springs and caves (e.g. Yanchep National Park).
8
Department of Water
Declining water levels in shallow groundwater systems have been linked with negative
ecological changes and loss of biodiversity (Froend et al. 2004). Fire and drought-induced
acidification are of concern in about one-third of the wetlands monitored on the Gnangara
Mound (Clark & Horwitz 2005).
The limestone caves in Yanchep National Park are drying out for longer periods in summer.
Some of these caves support occurrences of the critically endangered aquatic root-mat
community of the Swan coastal plain. These include very small subterranean fauna known
as stygofauna. Some species may only exist in a single cave. If the current drying trend
continues, some stygofauna species will be at extreme risk of extinction.
The decline in the watertables has resulted in Ministerial water-level criteria being breached
and a general deterioration of the environmental, social and cultural values of lakes and
wetlands. The number of Ministerial water-level criteria breaches is increasing. In 2004, the
EPA warned that management of Gnangara Mound groundwater was no longer sustainable
(EPA 2004a).
The Department of Water artificially supplements Lake Nowergup, a Conservation Category
Wetland that provides habitat for waterbirds and turtles. To maintain water levels, the lake is
supplemented with approximately 1.4 GL of water per year, sourced from the Leederville
aquifer, at a cost of about $50 000 per year (McHugh et al. 2008). The Water Corporation’s
artificial maintenance of Lake Jandabup has improved the lake’s quality but has been unable
to keep up with falling water levels. A groundwater bore and pipeline has been established to
re-hydrate part of the Yanchep cave system by putting local water mounds in place at seven
of the caves that support root-mat communities (CALM 2005).
In April 2007, the Gnangara Sustainability Strategy (GSS) was announced as a crossgovernment4 initiative to prepare an action plan to ensure a sustainable future for the mound.
The GSS action plan is scheduled for release in mid-2009.
On the Jandakot Mound the watertable has also declined. Some valuable wetlands have
directly altered hydrological states due to drainage input. These are Thomsons Lake, Bibra
Lake, Kogolup Lake and the Spectacles (McHugh et al. 2008). Table 1 displays examples of
wetlands under pressure on the Gnangara and Jandakot mounds.
Table 1
Examples of groundwater-dependent wetlands under stress
Wetland
Stress
Location
Lake Nowergup
Water levels artificially maintained
Gnangara Mound
Lake Yonderup
Severe risk of drawdown
Gnangara Mound
Big Carine Swamp
Severe risk of drawdown
Gnangara Mound
Loch McNess
Severe risk of drawdown
Gnangara Mound
Lake Jandabup
Falling water levels despite artificial water-level
maintenance
Gnangara Mound
Lake Gnangara
Permanently acidified site. Severe risk of drawdown
Gnangara Mound
Lake Mariginiup
Susceptible to acidification. Severe risk of drawdown
Gnangara Mound
Lake Pinjar
Severely degraded from agriculture land use
Gnangara Mound
EPP 78
High risk of ecological impact due to water-level declines
Gnangara Mound
Kings Spring
Severe risk of drawdown
Gnangara Mound
4
The Department of Water has joined forces with the Department of Agriculture and Food WA, DEC, Department
for Planning and Infrastructure, Forest Products Commission, Water Corporation and CSIRO.
Department of Water
9
Wetland
Stress
Beenyup Road
Swamp
Location
Severe risk of drawdown
Jandakot Mound
Thomsons Lake
Severe risk of drawdown
Jandakot Mound
Spectacles North
Severe risk of drawdown
Jandakot Mound
North Lake
Severe risk of drawdown
Jandakot Mound
Forrestdale Lake
Severe risk of drawdown
Jandakot Mound
Shirley Balla Swamp
Severe risk of drawdown
Jandakot Mound
Mather Reserve
Severe risk of drawdown
Jandakot Mound
Harrisdale Swamp
Severe risk of drawdown
Jandakot Mound
Booragoon Lake
High concentrations of metals in sediments
Jandakot Mound
A recent Department of Water audit highlighted deficiencies in the current monitoring network
at both criteria and non-criteria shallow groundwater system sites on the Gnangara and
Jandakot mounds. The study concluded that a detailed investigation of shallow groundwater
systems, including a substantial upgrade of the existing monitoring network, is required to
maintain sustainable development of groundwater resources on the mounds (McHugh &
Bourke 2008).
3.3
Salinity
Stream salinity shows a clear relationship between land clearing and mean annual rainfall.
Rivers with very little catchment clearing are typically fresh, whereas those with significant
clearing have higher salinities – unless they are in very high rainfall areas (Mayer et al.
2005). Two large tributaries of the Avon River – the Brockman River and Wooroloo Brook –
drain mostly cleared catchments (Table 2).
Table 2
River salinity status (Mayer et al. 2005)
River
Salinity status
Ellen Brook
Marginal
Helena River
Brackish
Brockman River
Moderately saline
Susannah Brook
Fresh
Swan River
Moderately saline
Wooroloo Brook
Moderately saline
Avon River
Saline
Canning River
Fresh
An objective of the State salinity strategy (Government of Western Australia 2000) is to
protect and restore key water resources to ensure salinity levels are kept to a level that
permits safe, potable5 water supplies in perpetuity. The Helena River catchment is
5
The Australian drinking water guidelines (NHRMC 2004) sets the desired level of total dissolved solids in
potable water at no more than 500 mg/L TDS (i.e. fresh).
10
Department of Water
designated a ‘water resource recovery catchment’ (WRRC) for salinity management. The
Helena River is the largest tributary of the Swan River: it currently contributes only 30 per
cent of the inflow but 63 per cent of the salt load entering the Mundaring Reservoir (the
source of public water supply for the Goldfields and Agricultural scheme). The transfer of
freshwater from a pumpback dam constructed in 1971 provides up to 60 per cent of the
water supply in dry years and allows the water in the Mundaring Reservoir to remain fresh
(i.e. <500 mg/L TDS).
A recent salinity-situation statement predicted that the salinity of the Mundaring Reservoir
inflow will remain at 510 mg/L TDS – just above the 500 mg/L target – unless additional
recovery actions are taken or the low rainfall continues. If the below-average-rainfall pattern
continues, the mean annual salinity of inflow to the reservoir is predicted to decline below the
500 mg/L TDS target (Smith et al. 2007). A catchment recovery plan is in the early stages of
preparation.
Department of Water
11
4
Murray River basin
4.1
Values and conditions
The Murray River basin includes two river systems – the small, shorter Serpentine and the
longer Murray – both of which drain into the Indian Ocean through the Peel Inlet near
Mandurah. The Peel Inlet-Harvey estuarine system has significant ecological, recreational,
commercial and scientific values. The estuary supports the largest professional and
recreational estuarine fishery in the state (URS 2007).
At more than 26 000 ha, the Peel-Yalgorup system is the largest Ramsar Convention site in
the South West. It is an outstanding example of a shallow estuary and the largest in the
region, with substantial areas of saltmarsh. In terms of waterbird numbers, the Peel-Harvey
estuarine system is the most important in the South West (URS 2007). It is a principal
stopover for migratory wading birds and a major drought refuge area for the region’s
waterbirds.
The Economic development and recreation management plan for the Peel waterways (WRC
2002) highlighted the many positive attributes of the waterways but concluded that without
corrective action, the waterways could not sustain the increased recreational demands driven
by population growth. Under such stress, the environment would decline further unless action
was taken in the catchment to improve water quality throughout the system, and to restore
the environment and habitats of the rivers, particularly the Murray and Serpentine.
In 2003, the EPA reported that while the Dawesville Channel had been successful in
improving water quality in the main body of the Peel Inlet and Harvey Estuary, water quality
and environmental problems remained in the contributing rivers. These included deteriorating
water quality in the lower reaches of the Murray and Serpentine rivers, such as increased
nutrient concentrations, toxic phytoplankton blooms and fish kills.
Where seasonal wetlands once existed in the catchments, large modifications to surfacewater hydrology have occurred as a direct result of agricultural and urban development.
Extensive drainage networks cross the coastal plain and have major impacts on river flows
and water quality in the estuary. The networks intercept surface and ground waters and
rapidly deliver nutrients and sediments directly to the waterways. The condition of the
wetland systems and rivers are summarised in tables 3 and 4.
Table 3
Wetland
system
Condition of wetland systems
Current land use
Disturbance or threat
PeelHarvey
estuary
Nature conservation, commercial fishing
and recreation. Surrounding areas:
nature conservation, grazing,
recreational, residential. Urban areas
generally extend to the water’s edge.
Past/present: eutrophication, algal blooms,
mosquitoes, developments on the shoreline,
and dredging and dumping on tidal flats.
Potential: further urban development and
increased disturbance near the shoreline.
Lake
McLarty
system
Nature conservation, pasture, grazing
and recreation. Wetlands generally lack
buffers of native vegetation.
Past/present: eutrophication and exotic plants.
Potential: groundwater extraction, too-frequent
wildfire, development and management of
inflow drains.
Yalgorup
Lakes
system
Nature conservation, recreation, pasture
grazing and rural smallholdings.
Vegetation buffers surround some of the
smaller lakes but much of the site’s east
side has little or no buffer.
Past/present: algae (Cladophora vagabunda)
covering thrombolites. Extraction of
groundwater and nutrient input. Lack of plant
buffers. Potential: human activity on the shore
of Lake Clifton and impacts on thrombolites.
12
Department of Water
Table 4
Condition of rivers
River
Condition
Murray River
Environment problems of water quality, bank erosion and loss of landscape values.
Further urban and rural development along its course is a threat.
North and
South
Dandalup rivers
Both rivers have been dammed, reducing downstream flow. Fringing vegetation has
been lost along parts of the rivers and bank erosion has been exacerbated by
agricultural development.
Serpentine
River
River has been dammed, reducing downstream flow. Substantially altered by
extensive drainage of the coastal plain. Middle reaches affected by extensive river
training, desnagging and levees. A significant source of nutrients to Peel Inlet.
About 15 per cent of the riparian vegetation has been cleared or is badly degraded.
(Source: URS 2007)
4.2
Water quality improvement plan
The state and federal governments co-funded the development of the Coastal Catchments
Initiative (CCI) program for the Peel-Harvey estuarine system. A suite of CCI projects
contributed to the development of the Water quality improvement plan for the rivers and
estuary of the Peel-Harvey system – phosphorus management (EPA 2008). Figure 5 shows
the three catchments6 covered by the plan.
The plan’s main focus is reducing phosphorous loads. The large stores of phosphorus in the
soils and sediments of the coastal portion of the Peel-Harvey catchment will take years to
leach out of the soil. The plan is therefore a long-term one – as significant changes in water
quality may require 20–50 years (EPA 2007a).
The plan sets a median total-phosphorus-load target of 75 tonnes/yr for the estuary. The
estuary’s current winter load is an estimated 145 tonnes/yr. About a 60 per cent reduction in
phosphorous load (i.e. from 69 tonnes/yr to 21 tonnes/yr) is required in the Serpentine
catchment. Measures to reduce phosphorus inputs to the estuary include:
•
management of agricultural land practices – better fertiliser, soil amendment and
irrigation practices, as well as perennial pastures
•
management of urban land practices – better fertiliser and soil amendment practices,
and water sensitive design
•
retrofitting of septic tanks with nutrient-reducing alternatives, full connection to
sewerage, and clean-up of livestock practices
•
licensing of agricultural nutrient discharges
•
continued research and evaluation of best-management practices (BMPs) and
reduction of barriers to their uptake
•
a monitoring and reporting program of suitable indicators and targets
•
community partnerships to promote awareness and collective resource management.
In 2006, the state government announced its intention to replace the use of highly watersoluble phosphorus fertilisers with low water-soluble phosphorus fertilisers within
environmentally sensitive areas (JGFIWP 2007). The change would help reduce
phosphorous loads in the Moore, Swan and Peel-Harvey estuaries.
6
The Harvey catchment is outside the boundary of the Peel-Peel regional water plan but is included in the
Department of Water’s South West regional water plan.
Department of Water
13
Figure 5 Peel-Harvey water quality improvement plan catchments (EPA 2007a)
In 2008, a DEC-led inter-agency working group formulated a plan to progress implementation
of the Fertiliser action plan (DEC 2008). It recommended that the Environment Minister:
•
develop a State Environmental (Phosphorus Fertiliser) Policy
•
establish a management/advisory council with industry, user groups and government
representation to oversee the implementation and review of the policy.
The Peel-Harvey water quality improvement plan addresses only phosphorus loads but
acknowledges other problems such as elevated nitrogen levels, estuarine and riverine
habitat loss, acid soil drainage, and bacteria levels (EPA 2007a). These issues are to be
addressed in a catchment management plan for the estuarine system.
Other key environmental issues facing wetlands and waterways are large-scale clearing and
the condition of remnant vegetation. Remnant native-vegetation cover ranges from about 5–
48 per cent and in many cases is dominated by weeds (PHCC 2007). The Murray River is
14
Department of Water
Comment [__1]: subcatchme
nt should be lower-case s and
not have a hyphen in the map’s
labels
seasonally brackish up to Pinjarra while the Serpentine River is seasonally brackish up to
Lake Amarillo.
4.3
Drainage and stormwater planning
Rural drainage networks have already altered much of the Swan coastal plain. These
networks not only convey excess water from the land, but also significant amounts of
nutrients and other contaminants (e.g. pesticides) that make their way into receiving
waterbodies.
Rural drainage schemes were developed decades ago to enable agricultural development of
the low-lying and poorly drained land. The Mundijong and Waroona drainage districts are
located in the Peel subregion. These two districts have 1020 km of drains managed by the
Water Corporation. There are also 2455 km of non-gazetted drains in the Peel-Harvey
catchment.
During the past 10–15 years, there has been a dramatic shift in the planning philosophy
underpinning drainage and stormwater management. Current best-management practice7
greatly reduces emphasis on ‘end of pipe’ water quality treatment solutions and prioritises
‘preventative’ measures, such as:
•
retention of existing natural drainage lines
•
‘at-source’ non-structural controls
•
small-scale infiltration systems.
The sensitivity of the palusplain to urban development associated with the expanding southwest and south-east urban corridors is reflected in the following statement in the State of play
of the Peel-Harvey eastern estuary catchment:
There is a need for extreme caution to be displayed in all preliminary planning processes
that are underway, until such time as the [Department of Water’s] Urban Drainage
Initiative studies have been completed. There is a potential risk that proposals that are
developed prior to the completion of this work may require substantial modification once
the Urban Drainage Initiative work is complete. Without a cautionary approach, there is a
risk that these developments may compromise the ‘water and sustainability’ outcomes
sought through the Urban Drainage Initiative (URS 2007 p.108).
The Department for Planning and Infrastructure (DPI) is preparing a policy framework to
guide the planning, development and implementation of a spatial plan for the southern
segments of the Perth metropolitan area and the Peel region, in accordance with the
principles of Network City (WAPC & DPI 2004). A broad urban growth strategy will inform the
development of future structure plans for the area. The drainage and water management
plans for the subregional planning area are integral to this work.
Water saving urban design (WSUD) approaches to water quality and stormwater
management rely to a large degree on the effective application of best-management
practices (BMPs). These are practical, structural or non-structural methods that reduce the
movement of sediment, nutrients, pesticides and other pollutants from the land to surface
water or groundwater.
The EPA has noted that deterioration in water quality from urban development cannot be
ruled out. This is because modelling and experience do not yet allow confident prediction that
water quality can be managed adequately (EPA 2008). There is a knowledge gap on how
7
The Stormwater management manual for Western Australia provides guidance on implementing best-practice
urban stormwater management (Department of Water 2004–07).
Department of Water
15
BMPs perform under Western Australian conditions. The Liege Street Wetland constructed in
Cannington is one of the few demonstration projects to be evaluated (GHD 2007). A rigorous
evaluation program is needed to determine the effectiveness of the various BMPs for WSUD
under conditions similar to the Perth-Peel region. This knowledge would help the setting of
appropriate water quality management targets.
4.4
Peel-Harvey system governance
Many stakeholders in the Peel region identified the need for more coordinated governance of
the Peel-Harvey estuarine system. The SRT was identified as a governance model: it has
one clearly identifiable management body that acts as an umbrella under which the trust and
other agencies and groups conduct a range of programs for the betterment of the SwanCanning river system. The Peel-Harvey system does not have a similar singular public face.
As a result, often the public does not know which agency should be contacted on a given
issue. Problem issues are passed from agency to agency before reaching the right hands
and the system is inefficient.
An inter-agency working group (EPA, WAPC, DAFWA, PHCC, PDC, DEC, DPI and the
Department of Water) recently considered options for a new governance arrangement for the
Peel-Harvey. It recommended a governance model whereby key partners in the region were
represented and environmental planning and management were integrated with stronger
urban planning and management, not only for the waterways but for all urban and rural
lands.
16
Department of Water
5
Waterways and wetlands as ecological
linkages
Much of the landscape in the metropolitan region, especially the coastal plain, is defined as:
fragmented to such an extent that substantial loss of biodiversity has or is already
occurring and the survival of remaining species even in large, consolidated, regionally
significant areas will depend on well-planned and managed ecological linkages in
conjunction with careful management of the protected areas that are being linked. Thus,
the long-term viability and conservation values of Bush Forever sites, CALM-managed
estate and regional parks depend in part on an effective network of regional ecological
linkages (Del Marco et al. 2004 p.66).
The Perth Biodiversity Project’s objective for ecological linkages is to connect natural areas,
preferably with continuous corridors of native vegetation, in ways that allow fauna and flora to
move between these areas to access resources and suitable habitat for survival and
reproduction. Even relatively small natural-vegetation patches can serve as stepping stones
for species dispersal or recolonisation.
One of the primary goals of the State biodiversity strategy (DEC 2006) is to create largescale regional ecological linkages that include a comprehensive conservation reserve system
and complementary off-reserve initiatives. The SRT has advocated the establishment of
linkages and greenways to form an integrated system of regional parks, conservation areas,
recreation nodes and public spaces around water resources (SRT & WAPC 2002).
At a regional scale, the following programs include a focus on ecological linkages:
•
Swan Bioplan (DEC)
•
Perth Biodiversity Project (WALGA)
•
Riverbank and Riverpark programs (SRT)
•
Ecological Linkages Program (Perth Region NRM)
In highly fragmented landscapes, where continuous corridors of vegetation rarely exist, river
environments and wetland chains are significant assets. Wetlands and waterways are natural
linkages as their fringing and wetland vegetation provide a connection between terrestrial
and aquatic environments. The vegetation provides habitat, protects aquifers and allows
movement of genetic materials between populations.
Figure 6 displays the regional ecological linkages identified by the Perth Biodiversity Project
for the Perth metropolitan region. Wetland chains on the Gnangara Mound and near
Rockingham and rivers including the Swan-Canning provide vital ecological linkages. Many
of these waterways and wetlands are already in protected areas or regional parks and serve
additional recreational and cultural/heritage purposes.
Within the Perth-Peel region the native vegetation along some rivers and creek lines is
limited and in poor condition (e.g. invasive species and stock access). Pressures include:
•
The foreshore reserves of some wetlands and waterways are vested in multiple
parties (e.g. local governments and state government agencies). In such cases,
active vegetation management is often limited or non-existent due to a shortage of
resources.
•
Outside the metropolitan area, many waterways have yet to undergo floodplain
mapping and there are few foreshore reserves in place. In areas such as the
Brickman River in Chittering, there is increasing pressure to subdivide rural land
holdings. In such areas, while the opportunity still exists, a proactive approach is
Department of Water
17
needed to map the floodplains and establish foreshore reserves that complement the
objectives of programs such as the Perth Biodiversity Project.
Waterways that serve as ecological linkages will come under increasing pressures from
climate change including:
•
increased flooding and inundation due to rising sea levels
•
decreased streamflows
•
increased sedimentation
•
reduced water quality
•
changes in the distribution and abundance of foreshore vegetation (SRT 2008).
The highest priority for establishing waterway or wetland-based ecological linkages is the
Peel-Harvey catchment, which is under increasing pressure from rapid urbanisation and
higher levels of water-based recreation.
The planning for the Peel Regional Park is ongoing (ERM 2005). The park will consist of the
foreshores of the Peel-Harvey estuary and the floodways of the Murray, Serpentine and
Harvey rivers that flow into the estuary (Figure 7). Key management issues for the park
include:
18
•
conservation and protection of wetlands, particularly through maintenance and
improvement of water quality by reducing nutrient inputs
•
protection and management of foreshores
•
protection of native vegetation
•
provision of ecological linkages.
Department of Water
Figure 6
Draft regional ecological linkages for the Perth metropolitan region
(Del Marco et al. 2004)
Department of Water
19
Figure 7
20
Peel Regional Park
Department of Water
6
Climate change
6.1
Potential impacts
Climate change has the potential to profoundly change the region’s waterways. An SRT
study (2007) predicted the Swan-Canning river system would experience:
1
continued increases in atmospheric and water temperatures
2
an acceleration in sea and river-system water-level rise
3
decreases in winter rainfall and streamflow
4
decreases in groundwater levels and consequent flows to drains and streams
5
increases in warm spells and heat wave frequency.
The Climate change, water demand and water availability scenarios to 2030 background
paper explores the issue of climate change and its implications for water availability. By
2030, streamflows may decrease by ~25 per cent (relative to 1980–99) for the median
climate scenario and by ~47 per cent for the drier scenario. These are significant reductions
with large implications for water supply security and dependent ecosystems. As groundwater
levels decrease, climate change may increase the risk of acidification and heavy metal
contamination from disturbance of acid sulfate soils.
A drier climate could exacerbate many of the region’s existing environmental problems. For
example, estuaries and some other waterways would become more marine in nature. The
amount of freshwater flowing into the estuaries would be reduced, as would the seasonal
flushing effect that occurs during periods of high flow. The conditions of the estuary would
become more closely linked with the conditions of the ocean tides. Since sea levels are
expected to rise and storm surges to increase, this increases the likelihood of saltwater
intrusion into the Swan estuary (SRT Technical Advisory Panel 2007).
The impact of climate change on eutrophication and sedimentation is unclear. While the
amount of sediments and nutrients entering the Swan-Canning is expected to decrease,
retention of these particulates is expected to increase. This is because a decrease in rainfall
translates to a decrease in runoff; however, it also means a decrease in streamflows. With
decreased streamflows, sediments and nutrients will not be ‘flushed out’ into the ocean as
they usually are during high flows.
An extension of the warm, still conditions that characterise the ‘autumn’ phase of the SwanCanning River could lead to less mixing, stronger stratification (layering) in the water column,
low oxygen levels and increased nutrient release from the sediments. Such conditions favour
the creation of algal blooms and place stress on aquatic organisms (SRT Technical Advisory
Panel 2007).
Climate change is expected to impact on biodiversity and species composition. Examining
the likely local effects of climate change on the Peel-Harvey catchment, Hick (2006)
described the following potential impacts on waterways and wetlands:
•
a change in species composition and a loss of valuable diversity in ephemeral
wetlands
•
a reduction in water-logging and perhaps a reduction in stream salinity in the long
term
•
higher sea level and greater tide flow and velocities resulting in the loss of some intertidal habitats including some Ramsar-listed wetlands
Department of Water
21
•
existing habitat and biological systems disappearing; some species will adapt,
emigrate or will be restricted to refuges
•
new ecosystems will establish.
6.2
Ecological water needs
Ecological water requirements (EWRs) describe the water regimes needed to sustain the
ecological values of water-dependent ecosystems at a low level of risk. Seasonal and annual
variability of flow is essential to maintaining healthy aquatic ecosystems. Environmental flows
within waterways are important to improve streamflow and to protect in-stream and riparian
habitat and biodiversity.
Groundwater abstraction and water storages on rivers have placed significant pressures on
groundwater and surface-water resources and their dependent ecosystems. The declining
watertable on the Gnangara Mound is having a negative impact on wetlands. Large public
water supply dams and reservoirs in the Hills regulate many of the major rivers in the PerthPeel region. In the case of Canning River system, the dams have reduced average annual
downstream flows by 98 per cent. Most of the major dams were already in place before the
concept of environmental flows or EWRs was introduced in the 1990s.
EWRs and environmental flows have been defined for many of the region’s groundwater
resources but few of the rivers affected by public water supply dams. In undisturbed
environments, EWRs are determined with the aim of protecting existing ecological values at
a low level of risk (WRC 2000). However, if a river has already been significantly modified,
EWRs can be established to:
•
maintain the current key ecological values at low risk
•
maintain and/or enhance current key ecological values
•
restore pre-existing or pre-disturbance ecological values
•
provide for a combination of current key ecological values and key pre-existing
natural ecological values (DoW 2007).
For rivers in the region with major public water supply dams, returning flow regimes to their
status before dam construction is impractical and unattainable – especially with a drying
climate. However, the environmental flows set for the region’s rivers should be reviewed and
to the extent it is feasible, the water regime should complement the needs of dependent
wetlands and floodplains and downstream water quality. In some instances, this will require
more water to be released from some public water supply dams. In other instances, the
volume of flow may not change significantly but adjustments will be needed to the timing and
nature of releases to mimic natural frequency, duration and seasonal flows.
In the case of the Gnangara Mound wetlands and other groundwater-dependent ecosystems,
determining appropriate management objectives will be an important part of the statutory
groundwater water management plan that will follow the Gnangara Sustainability Strategy.
22
Department of Water
Appendices
Appendix 1 — Existing programs
Program
Coastal Catchments
Initiative (CCI)
Agency
Summary
SRT, EPA,
PHCC, Perth
Region NRM
A draft water quality improvement plan has been
prepared for Peel-Harvey and will be prepared for the
Swan-Canning. Aimed at reducing nutrient inputs.
Swan-Canning Cleanup
Program (phasing out)
SRT
Established to tackle the increasing incidence of algal
blooms in the Swan and Canning rivers. The Healthy
Rivers Program is the second phase of this work.
Healthy Rivers Program
SRT
Eight key management programs to drive the next
phase of managing the Swan-Canning river system:
• Coordination
• Healthy Catchments
• Land Use Planning
• Drainage Nutrient Intervention
• Riverbank
• River Health
• River Guardians
• River Science
Non-Nutrient
Contaminants Program
SRT
Assesses non-nutrient contaminants in the system.
Includes the Swan-Canning Industry Project.
Foreshore Assessment
Program
SRT, Perth
Region NRM
The foreshore assessment is completed and a
foreshore management strategy published.
Swan Alcoa Landcare
Program
SRT
Goal is the retention, restoration and protection of
bushland, coastal, wetland and riverine vegetation.
Water Quality Monitoring
and Evaluation
Framework
Perth Region
NRM
Part of the Integrated Water Management Program.
The framework will also provide the baseline for
monitoring and evaluation and enable the Perth
Region NRM to evaluate its effectiveness in improving
water quality.
Sustainable Production
RDP
Perth Region
NRM
Wooroloo Salinity Management Project
Bellevue Sustainable Industry Project
SME Sustainability Project - pilot project focused on
moving SMEs toward BMPs
Superficial Aquifer Health
Project
Perth Region
NRM
Implements projects to revegetate and fence riparian
areas in strategic areas.
Avon Upper Swan
Nutrient Intervention and
Salinity Amelioration
Project
Perth Region
NRM
Focused on the implementation of the Ellen Brook and
Brockman River catchment plans.
Wetland Watch
Perth Region
NRM, WWF
Focuses on high-value wetlands on private property.
Wetlands Indigenous
Project
Perth Region
NRM
Management of wetlands for Indigenous values.
Ribbons of
Blue/Waterwatch WA
Perth Region
NRM
Encourages local communities to be actively involved
in learning about and protecting environmental water
Swan-Canning system
Department of Water
23
Program
Agency
Summary
quality.
Peel-Harvey system
Rivercare
PHCC
Aims to protect and restore priority rivers in the
catchment:
• river action planning for the Murray River
• drainage BMPs in the Serpentine River
Peel-Yalgorup system
PHCC
Preparation of a management plan for the Ramsarlisted Peel-Yalgorup System.
Ecological character description.
Hotham Williams Murray
River Salinity Recovery
Project
PHCC
A strategic initiative of the South West Catchment
Council, funded through the National Action Plan for
Salinity and Water Quality.
Man and the Biosphere
Project
PHCC, Alcoa
This project is exploring the concept of a biosphere in
the Peel-Harvey
Local Government Water
Resource Management
Project
PHCC
ICLEI Water Campaign
Design and operation of
coastal drainage systems
PHCC
Development of a drainage management plan for the
Peel-Harvey catchment
Water quality
improvement plan
EPA, PHCC
A comprehensive plan to reduce phosphorous loads in
the Peel-Harvey system through changes to land
management practices
NACC
Aims to protect and restore priority rivers in the NAR,
including the Moore River and Gingin Brook.
Bush Forever
WAPC/DPI
Aims to protect a target figure of at least 10 per cent of
the 26 original vegetation complexes within the SCP
portion of metropolitan Perth.
Perth Biodiversity Project
Perth Region
NRM , DPI,
WALGA
Supports participating local governments in
implementing the National Local Government
Biodiversity Strategy.
SCP Targeted Biodiversity
Project
PHCC, SWCC
Conservation of priority remnant vegetation within the
Swan coastal plain.
Ecological Linkages
Program
Perth Region
NRM
Aims to identify species that depend on wildlife
corridors.
Moore River
Rivercare
Biodiversity
24
Department of Water
Appendix B — significant waterways and wetlands
The information in this appendix is drawn from the EPA’s Draft guidance statement no. 33:
Environmental guidance for planning and development (2005).
Wetland protection
The EPA’s Position statement no. 4 on the environmental protection of wetlands (EPA
2004b) sets out the EPA’s overarching goals for wetlands, as follows:
•
to protect the environmental values and functions of wetlands in Western Australia
•
to protect, sustain and, where possible, restore the biological diversity of wetland
habitats in Western Australia
•
to protect the environmental quality of the wetland ecosystems of Western Australia
through sound management in accordance with the concept of ‘wise use’, as
described in the Ramsar Convention, and ecologically sustainable development
principles, regardless of land use or activity
•
to have as an aspirational goal, no net loss of wetland values and functions.
The EPA considers that the wetlands below are of high conservation significance and require
a high level of protection:
•
conservation category wetlands as identified on DoE’s Geomorphic Wetlands Swan
Coastal Plain Dataset
•
wetlands protected under the Environmental Protection (Swan Coastal Plain Lakes)
Policy 1992.
•
wetlands recognised by the Ramsar Convention on Wetlands of International
Importance
•
wetlands supporting waterbirds listed in the Japan Australia Migratory Bird
Agreement (JAMBA) and the China Australia Migratory Bird Agreement (CAMBA)
•
wetlands identified in A Directory of Important Wetlands in Australia
•
wetlands in sites on the Register of the National Estate
•
wetlands in Perth’s Bush Forever sites and Regional Open Space in the Greater
Bunbury Region Scheme and the Peel Region Scheme
•
wetlands in sites recommended for protection in the Systems ‘Red Book’ reports
(Department of Conservation and Environment 1976–1983) except where
superseded by later conservation recommendations adopted by government
•
wetlands on land vested for National Park or Nature Reserve purposes, sites
endorsed by government for inclusion in the conservation estate, and sites
recommended for the conservation estate by government agencies responsible for
biodiversity protection and conservation
•
wetlands with significant vegetation, significant flora or habitat that supports
significant fauna as accepted by the EPA, for example, threatened ecological
communities, Declared Rare Flora, Specially Protected Fauna
•
wetlands identified as ‘conservation category’ following application of an EPArecognised methodology
Department of Water
25
•
wetlands identified as having high conservation significance by an authority on
wetlands, for example, DoE or the Department of Conservation and Land
Management (CALM), or following a thorough process, subject to confirmation by the
EPA.
Table B1 Wetland management categories (EPA 2005)
Management
category
General description
Management objectives
Conservation
Wetlands which support
a high level of ecological
attributes and functions
Highest priority wetlands. Objective is to preserve and
enhance the existing conservation values of the
wetlands through various mechanisms including:
• reservation in national parks, crown reserves and
State-owned land
• protection under Environmental Protection policies,
• wetland covenanting by landowners.
No development or clearing is considered appropriate.
These are the most valuable wetlands and any activity
that may lead to further loss or degradation is
inappropriate.
Resource
enhancement
Wetlands which may
have been partially
modified but still support
substantial ecological
attributes and functions
Priority wetlands. Ultimate objective is to manage,
restore and protect towards improving their conservation
value. These wetlands have the potential to be restored
to conservation category. This can be achieved by
restoring wetland function, structure and biodiversity.
Protection is recommended through a number of
mechanisms.
Multiple use
Wetlands with few
remaining important
attributes and functions
Use, development and management should be
considered in the context of ecologically sustainable
development and best-management practice catchment
planning through landcare.
Waterway protection
The position of the EPA is that all waterways have environmental significance. It is preferable
to maintain the natural dynamic water regime of each waterway in terms of water quality,
water course alignment, flow quantity and the timing of flows in and entering the waterway.
The EPA’s objective for waterways is to maintain their integrity, ecological functions and
environmental values (EPA 2004b).
The EPA considers that the portions of waterways and their buffers in the areas listed below
require a high level of protection during strategic planning, decision-making and ongoing
management:
26
•
wild rivers (note: there are none in the Perth-Peel region)
•
areas endorsed by government for inclusion in the conservation estate
•
areas recommended for protection in the Systems ‘Red Book’ reports
•
areas reserved through the planning process for purposes which include conservation
•
ecological linkages that connect high-value conservation areas
•
key habitat areas, for example, key fish breeding areas and areas on which birds that
are the subject of the JAMBA and CAMBA migratory bird agreements depend
Department of Water
•
other areas with significant vegetation, significant flora or significant fauna
•
areas that include significant wetlands
•
public drinking water supply catchments
•
all estuaries and inlets and their associated wetlands and buffers, except for portions
agreed for uses such as ports following public processes accepted by the EPA
•
areas that include important landscapes or landforms or sites of high heritage
significance
•
other waterway areas recommended for conservation by recognised authorities
following rigorous processes as accepted by the EPA.
Department of Water
27
Shortened forms
BMP
best-management practice
CCI
Coastal Catchment Initiative
CALM
former (department of) Conservation and Land Management
CSIRO
Commonwealth Scientific and Industrial Research Organisation
CAMBA
China Australia Migratory Bird Agreement
DEC
Department of Environment and Conservation
DAFWA
Department of Agriculture and Food WA
DPUD
former Department of Planning and Urban Development
DoE
former Department of Environment
DoH
Department of Health
DoW
Department of Water
DPC
Department of Premier and Cabinet
DPI
Department for Planning and Infrastructure
EPA
Environmental Protection Authority
FPC
Forest Products Commission
GAWS
Goldfields and Agricultural Scheme
GSS
Gnangara Sustainability Strategy
GW
groundwater area
ICLEI
International Council for Local Environmental Initiatives
ILWMP
integrated land and water management plan
IOCI
Indian Ocean Climate Initiative
IWSS
Integrated Water Supply Scheme
JAMBA
Japan Australia Migratory Bird Agreement
KIA
Kwinana Industrial Area
KIC
Kwinana Industries Council
KWRP
Kwinana Water Reclamation Plant
LGA
local government area
MAR
managed aquifer recharge
MRPA
former Metropolitan Region Planning Authority
MRS
Metropolitan Region Scheme (MRS)
NACC
Northern Agricultural Catchments Council
NRM
natural resource management
NWI
National Water Initiative
PDWSAs public drinking water source areas
PHCC
28
Peel-Harvey Catchment Council
Department of Water
PDC
Peel Development Commission
POS
public open space
PPRWP
Perth-Peel regional water plan
PWS
public water supply
SCC
Swan Catchment Council
SDOOL
Sepia Depression Ocean Outfall Line
SME
small- to medium-size enterprise
SPP
State planning policy
SRT
Swan River Trust
SWCC
South West Catchments Council
UWPCAs underground water pollution control areas
WALGA
Western Australian Local Government Association
WAPC
Western Australian Planning Commission
WCP
water conservation plan
WELS
Water Efficiency Labelling and Standards Scheme
WRC
Water and Rivers Commission (now Department of Water)
WRMS
water resource management strategy
WRRC
water resource recovery catchment
WSUD
water sensitive urban design
WWF
World Wildlife Fund – Australia
WWTP
wastewater treatment plant
Department of Water
29
References
Alderman, A & Clarke, M 2003, Moore River catchment appraisal: Resource Management
Technical Report 263, prepared for the Northern Agricultural Region, Rapid Catchment
Appraisal Team, Department of Agriculture.
Appleyard, SJ, Angeloni, J & Watkins, R 2006, ‘Arsenic-rich groundwater in an urban area
experiencing drought and increasing population density, Perth, Australia’, Applied
Geochemistry, 21,1, 83-97.
CALM – see Conservation and Land Management
Conservation and Land Management 2005, Annual report (2004–2005), Government of
Western Australia, Perth, WA.
Clark, JD & Horwitz, P 2005, Annual report for the wetland macroinvertebrate monitoring
program of the Gnangara Mound Environmental Monitoring Project – spring 2004 to
summer 2005, report to the Department of Environment, Perth, WA.
Del Marco, A, Taylor, R, Clarke, K, Savage, K, Cullity, J & Milles. C 2004, Local government
biodiversity planning guidelines for the Perth metropolitan region, Perth Biodiversity
Project, Western Australian Local Government Association, Perth, WA.
DEC – see Department of Environment and Conservation
Department of Environment and Conservation 2006, Draft – A 100-year biodiversity
conservation strategy for Western Australia: Blueprint to the bicentenary in 2029,
Government of Western Australia, Perth, WA.
Department of Water 2007, Environmental values, flow related issues and objectives for the
Canning River, Western Australia: From the Canning Dam to Kent St Weir, Government
of Western Australia, Perth, WA.
DoW – see Department of Water
Economics Consulting Services 2008, Peel waterways: An economic evaluation, prepared
for the Department of Water. Perth, WA.
ECS – see Economics Consulting Services
EPA – Environmental Protection Authority
Environmental Protection Authority 2004a, Environmental management of groundwater
abstraction from the Gnangara Mound July 2000 – June 2003 – triennial report, Bulletin
1139, Government of Western Australia, Perth, WA.
— 2004b, Environmental protection of wetlands, Position statement no. 4, Government of
Western Australia, Perth, WA.
— 2005, Environmental guidance for planning and development, Draft guidance statement
no. 33, Government of Western Australia, Perth, WA.
— 2007a, Draft water quality improvement plan for the rivers and estuary of the Peel-Harvey
system, Government of Western Australia, Perth, WA.
— 2007b, State of the environment report: Western Australia 2007, Government of Western
Australia, Perth, WA.
— 2008, Keralup (formerly Amarillo) masterplan, Karnup, EPA Bulletin 1281, Government of
Western Australia, Perth, WA.
Estill & Associates 2005, Study of groundwater-related Aboriginal cultural values on the
Gnangara Mound, Western Australia, report for Department of Environment, Perth, WA.
30
Department of Water
Froend, RH, Rogan, R, Loomes, R, Horwitz, P, Bamford, M & Storey, A 2004, Study of
ecological water requirements on the Gnangara and Jandakot mounds under Section 46
of the Environmental Protection Act. Tasks 3 & 5: Parameter identification and
monitoring program review, prepared for Water and Rivers Commission, Centre for
Ecosystem Management, Edith Cowan University. Joondalup, WA.
GHD 2007, Liege Street Wetland performance report 2005 to 2006, prepared for the Swan
River Trust, Perth, WA.
Government of Western Australia 2000, Natural resource management in Western Australia,
The salinity strategy, Government of Western Australia, Perth, WA.
Hick, P 2006, Understanding, quantifying & demonstrating the likely local effects of climate
change & variability in the Peel-Harvey catchment, Peel-Harvey Catchment Council,
Mandurah, WA.
JGFIWP – see Joint Government and Fertiliser Industry Working Party
Joint Government and Fertiliser Industry Working Party 2007, Fertiliser action plan: Phasingout the use of highly water soluble phosphorus fertilisers in environmentally sensitive
areas of South West, Western Australia, a report to the Western Australian Minister for
the Environment, Government of Western Australia, Perth, WA.
Mayer, XM, Ruprecht, JK & Bari, MA 2005, Stream salinity status and trends in south-west
Western Australia, Department of Environment, Salinity and land use impacts series,
Report No. SLUI 38, Government of Western Australia, Perth, WA.
McHugh, SL & Bourke, SA 2008, Management area review of shallow groundwater systems
on Gnangara and Jandakot mounds, prepared for Department of Water, Perth, WA.
NACC – see Northern Agriculture Catchment Council
Northern Agriculture Catchment Council 2005, Natural resource management strategy,
Northern Agriculture Catchment Council, Perenjori, WA.
Peel-Harvey Catchment Council 2007, PHCC DSS toolbox, Satellite Remote Sensing
Services – Landgate, Government of Western Australia, Perth, WA.
PHCC – see Peel-Harvey Catchment Council
SCC – see Swan Catchment Council
Seddon, G 1971, Sense of place: A response to an environment, the Swan coastal plain,
Western Australia, UWA Press, Nedlands, WA.
Smith, RA, Bari, MA, Dixon, RNM & Rowlands, DW 2007, Helena River salinity situation
statement, Department of Water, Western Australia, Water resource technical series,
no. WRT 34, 190p.
Swan Catchment Council 2004, The Swan region strategy for natural resource management,
Swan Catchment Council, Midland, WA.
SRT – see Swan River Trust
Swan River Trust 2006, Draft Healthy Rivers action plan, Government of Western Australia,
Perth, WA
— 2007, Swan River Trust annual report 2006–2007: Caring for the Swan and Canning
rivers, Government of Western Australia, Perth, WA.
— 2008, Swan and Canning rivers foreshore: Assessment and management strategy,
Government of Western Australia, Perth, WA.
Department of Water
31
Swan River Trust & WAPC 2002, Swan and Canning rivers precinct planning project:
Precinct plan handbook, Government of Western Australia, Perth, WA.
Swan River Trust Technical Advisory Panel 2007, Potential impacts of climate change on the
Swan and Canning rivers, Government of Western Australia, Perth, WA.
URS 2007, The state of play: Peel-Harvey eastern estuary catchment environmental
assessment discussion paper, prepared for the Department of Water, Perth, WA.
WAPC – see Western Australian Planning Commission
Water and Rivers Commission 2000, Statewide policy no. 5, Environmental water provisions
policy for Western Australia, Government of Western Australia: Perth, WA.
— 2002, Economic development and recreation management plan for the peel waterways,
prepared by Everall Consulting Biologists, Perth, WA.
Western Australian Planning Commission & DPI 2004, Network City: Community planning
strategy for Perth and Peel, Government of Western Australia, Perth, WA.
WRC – see Water and Rivers Commission
Williams, DR & Vaske JJ 2003, ‘The measurement of place attachment: Validity and
generalizability of a psychometric approach’, Forest Science, 49(6): 830-840.
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Department of Water