THE PLAN
Water Supply Project - Dublin Region
October 2010
Water Supply Project – Dublin Region
The Plan
TABLE OF CONTENTS
1
INTRODUCTION .................................................................................................. 1
1.1
BACKGROUND............................................................................................................. 1
1.2
RELEVANT NATIONAL POLICY FRAMEWORK ......................................................... 2
1.3
DUBLIN REGION (WATER SUPPLY AREA) ............................................................... 2
1.4
HISTORICAL CONTEXT............................................................................................... 4
1.5
OVER RIDING PURPOSE ............................................................................................ 6
1.6
PROJECT DEVELOPMENT (1996-2010)..................................................................... 7
1.6.1
Greater Dublin Water Supply Strategic Study 1996 / Year 2000 Review ........ 9
1.6.2
Feasibility Studies (3 Options) / SEA Phase 1 Stakeholder Consultations.... 10
1.6.3
SEA Phase 1 Additional Stakeholder Consultations ...................................... 10
1.6.4
Dublin City Council – Strategic Policy Committee / Expanded Range of
Options ........................................................................................................... 11
1.7
1.8
1.9
1.10
1.6.5
Feasibility Studies (10 Options) / SEA Phase 2 / Public Consultation ........... 11
1.6.6
Selection of Recommended Option / Stakeholder Feedback ........................ 13
NEED FOR PROJECT ................................................................................................ 13
1.7.1
Government Economic Growth Policy ........................................................... 13
1.7.2
Headroom / Security of Supply....................................................................... 14
1.7.3
Water Demand Growth................................................................................... 14
1.7.4
Demand / Supply Projections 2009 - 2040..................................................... 14
1.7.5
Timing of New Supply Requirements............................................................. 16
1.7.6
Peak Demand & Headroom Allowances ........................................................ 17
1.7.7
New Source Supply Requirements ................................................................ 18
1.7.8
Climate Change / Security of Supply ............................................................. 19
1.7.9
Economic Downturn (2008 – 2010)................................................................ 20
WATER SUPPLY OPTIONS ....................................................................................... 21
1.8.1
River Shannon Water Supply Options ........................................................... 22
1.8.2
Irish Sea Water Supply Option ....................................................................... 23
1.8.3
Other Water Supply Options .......................................................................... 23
1.8.4
General Option Overview ............................................................................... 24
EVALUATION OF OPTIONS ...................................................................................... 24
1.9.1
Option Evaluation Methodology ..................................................................... 24
1.9.2
Option Evaluation & Selection Process.......................................................... 25
SELECTION OF RECOMMENDED OPTION ............................................................. 27
1.10.1 Recommended Option F2 .............................................................................. 27
Environmental Advantages ......................................................................................... 28
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Technical & Economic Advantages............................................................................. 29
1.11
INFRASTRUCTURE – RECOMMENDED OPTION ................................................... 29
1.11.1 Key Infrastructure Components...................................................................... 29
2
1.12
COST OF RECOMMENDED OPTION........................................................................ 30
1.13
PROGRAMME – IMPLEMENTATION OF RECOMMENDED OPTION ..................... 31
NEED FOR PROJECT ........................................................................................33
2.1
INTRODUCTION ......................................................................................................... 33
2.2
IRISH GOVERNMENT ECONOMIC POLICY............................................................. 34
2.3
WATER SUPPLY – OBJECTIVES.............................................................................. 34
2.4
DEMAND PROJECTIONS .......................................................................................... 35
2.4.1
Maximum Planning Scenario.......................................................................... 35
2.4.2
Minimum Planning Scenario........................................................................... 36
2.4.3
Extent & Timing of Water Supply Needs........................................................ 36
2.4.4
Demand Projections Summary....................................................................... 37
2.5
DEMAND REQUIREMENTS – MIDLANDS ................................................................ 39
2.6
PRODUCTION CAPABILITY OF EXISTING SOURCES............................................ 39
2.7
DEMAND/SUPPLY BALANCE.................................................................................... 40
2.8
CLIMATE CHANGE..................................................................................................... 41
2.9
TIMING OF NEW SUPPLY REQUIREMENTS ........................................................... 41
2.9.1
3
Peak Demand & Headroom Allowances ........................................................ 42
2.10
EXTENT OF NEW SUPPLY REQUIREMENTS ......................................................... 44
2.11
PHASING .................................................................................................................... 45
2.12
NEW WATER SUPPLY SCHEME – PERFORMANCE CRITERIA ............................ 46
2.13
WATER PRODUCTION SOURCES 2009 – 2040 ...................................................... 46
WATER CONSERVATION..................................................................................47
3.1
INTRODUCTION ......................................................................................................... 47
3.2
HISTORY OF WATER CONSERVATION................................................................... 47
3.3
3.4
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Dublin Region Water Conservation Project (DRWCP 1998 / 99) .................. 47
3.2.2
Dublin Region Watermains Rehabilitation Project (2007 – 2012).................. 48
3.2.3
Water Conservation for Schools: Mr. Drippy Campaign ................................ 48
3.2.4
Tap Tips Campaign ........................................................................................ 48
3.2.5
Water Bye-Laws ............................................................................................. 48
WATER CONSERVATION SAVING POTENTIAL...................................................... 49
3.3.1
Measures in Place (2010) .............................................................................. 49
3.3.2
Future Potential Measures ............................................................................. 51
CONCLUSION & RECOMMENDATIONS................................................................... 52
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WATER FRAMEWORK DIRECTIVE ..................................................................53
4.1
SHANNON INTERNATIONAL RIVER BASIN DISTRICT ........................................... 53
4.1.1
Interaction / Relationship between the WSP-DR Plan and the Shannon RBMP
........................................................................................................................ 53
4.2
EASTERN RIVER BASIN DISTRICT .......................................................................... 56
4.2.1
4.3
5
INTRODUCTION ......................................................................................................... 57
5.1.1
Hydrological Modelling of the River Shannon ................................................ 59
5.1.2
Phased Water Supply Requirements from the New Supply Source .............. 60
5.1.3
Technical Evaluation of Water Supply Options .............................................. 60
5.1.4
Routing and Site Selection ............................................................................. 61
5.1.5
Economic Evaluation of Water Supply Options.............................................. 62
5.1.6
Environmental Assessment............................................................................ 62
5.1.7
Public Consultation......................................................................................... 62
LOUGH REE OPTIONS - EVALUATION SUMMARY ........................................63
6.1
6.2
7
CONCLUSION............................................................................................................. 56
WATER SUPPLY OPTIONS ...............................................................................57
5.1
6
Abstractions.................................................................................................... 56
TECHNICAL ASSESSMENTS .................................................................................... 64
6.1.1
Hydrological Model......................................................................................... 64
6.1.2
Modelling Conclusions for Options A, D, E and G – Lough Ree.................... 65
ENVIRONMENTAL ASSESSMENTS ......................................................................... 66
6.2.1
Strategic Environmental Assessment – Environmental Report ..................... 66
6.2.2
Habitats Directive Assessments..................................................................... 67
6.3
SOCIO ECONOMIC ASSESSMENT SUMMARY....................................................... 67
6.4
ECONOMIC ASSESSMENT SUMMARY.................................................................... 68
6.5
SUMMARY LOUGH REE WATER SUPPLY OPTIONS (A, D, E AND G).................. 68
LOUGH DERG / PARTEEN BASIN OPTIONS – EVALUATION SUMMARY ....70
7.1
7.2
TECHNICAL ASSESSMENTS .................................................................................... 72
7.1.1
Modelling of Abstraction Impacts from Lough Derg / Parteen Basin ............. 72
7.1.2
Water Levels in Lough Derg / Parteen Basin ................................................. 74
7.1.3
Flows in Lough Derg / Parteen Basin............................................................. 74
7.1.4
Modelling Results Summary........................................................................... 75
7.1.5
Modelling Results Conclusion ........................................................................ 77
ENVIRONMENTAL ASSESSMENTS ......................................................................... 77
7.2.1
Habitats Directive Assessments..................................................................... 78
7.3
SOCIO ECONOMIC ASSESSMENT SUMMARY....................................................... 79
7.4
ECONOMIC ASSESSMENTS..................................................................................... 79
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SUMMARY LOUGH DERG / PARTEEN BASIN OPTIONS (B, F2 AND C) ............... 80
8 DESALINATION / GROUNDWATER / LIFFEY BARROW OPTIONS –
EVALUATION SUMMARY........................................................................................82
8.1
8.2
TECHNICAL ASSESSMENTS – DESALINATION ..................................................... 83
8.1.1
Abstraction Location....................................................................................... 83
8.1.2
Selection of Optimum Desalination Technology ............................................ 83
8.1.3
Modelling of Brine Dispersion Impacts........................................................... 84
ENVIRONMENTAL / SOCIO ECONOMIC ASSESSMENTS DESALINATION .......... 85
8.2.1
9
Habitats Directive Assessments..................................................................... 85
8.3
ECONOMIC ASSESSMENTS DESALINATION ......................................................... 86
8.4
SUMMARY DESALINATION....................................................................................... 87
8.5
TECHNICAL ASSESSMENT GROUNDWATER ........................................................ 88
8.5.1
Groundwater Study Methodology................................................................... 89
8.5.2
Methodology for Deriving Potential Yields from Groundwater Bodies ........... 91
8.5.3
Constraints ..................................................................................................... 91
8.5.4
Summary of Groundwater Study .................................................................... 92
8.6
ENVIRONMENTAL ASSESSMENT OF GROUNDWATER........................................ 93
8.7
ECONOMIC ASSESSMENT GROUNDWATER......................................................... 93
8.8
SUMMARY GROUNDWATER .................................................................................... 94
8.9
TECHNICAL SSSESSMENT LIFFEY BARROW........................................................ 96
8.9.1
Water Availability from the Barrow ................................................................. 98
8.9.2
Water Availability from the Liffey .................................................................... 98
8.9.3
Water Availability - Liffey Barrow Conjunctive Use ........................................ 99
8.9.4
Hydrological Modelling ................................................................................. 100
8.9.5
Modelling Results Summary......................................................................... 100
8.10
ENVIRONMENTAL ASSESSMENT LIFFEY BARROW ........................................... 101
8.11
SUMMARY LIFFEY BARROW.................................................................................. 101
EVALUATION OF WATER SUPPLY OPTIONS...............................................102
9.1
METHODOLOGY FOR WATER SUPPLY OPTION EVALUATION ......................... 102
9.1.1
Sustainable Development ............................................................................ 102
9.1.2
Strategic Environmental Assessment (SEA)................................................ 102
9.1.3
Draft Plan (Technical Report) SEA Environmental Report / Habitats Directive
Report........................................................................................................... 103
9.2
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Evaluation Criteria / Assessment ................................................................. 103
9.1.5
Water Framework Directive.......................................................................... 104
SELECTION OF THE RECOMMENDED PREFERRED OPTION ........................... 105
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RANKING OF OPTIONS & SELECTION OF RECOMMENDED PREFERRED
OPTION..........................................................................................................106
10.1
ASSESSMENT CRITERIA ........................................................................................ 106
10.2
EVALUATION SUMMARY ........................................................................................ 107
10.2.1 Summary of Sustainability Analysis & Strategic Environmental Assessments..
...................................................................................................................... 115
10.2.2 Summary of Option – Advantages / Disadvantages .................................... 115
10.3
RECOMMENDED PREFERRED OPTION ............................................................... 117
10.3.1 Option Description........................................................................................ 117
10.3.2 Merits of Recommended Option F2 ............................................................. 118
11
10.4
EIA & HDA OF RECOMMENDED / PREFERRED OPTION .................................... 120
10.5
ADOPTION OF PREFERRED OPTION & SEA STATEMENT................................. 120
10.6
STATUTORY PLANNING PROCESS....................................................................... 120
MONITORING AND MITIGATION..................................................................122
11.1
INTRODUCTION ....................................................................................................... 122
11.2
MEASURES ALREADY IN PLACE ........................................................................... 122
11.2.1 Water Flows/Levels ...................................................................................... 122
11.3
PROPOSED MONITORING AND MITIGATION MEASURES.................................. 122
11.3.1 Conservation Measures ............................................................................... 122
11.3.2 Landscape .................................................................................................... 123
11.3.3 Energy .......................................................................................................... 123
11.3.4 Working Groups / Consultees ...................................................................... 123
11.3.5 ESB Agreement............................................................................................ 123
11.3.6 Bog Storage.................................................................................................. 123
11.3.7 Phytoplankton Dynamics.............................................................................. 123
11.3.8 Ecological Study on Bog Storage................................................................. 124
11.3.9 Shannon System Monitoring ........................................................................ 124
11.3.10 Pollan Survey ............................................................................................... 125
11.3.11 Invasive Species........................................................................................... 125
11.3.12 Hydrological Connections............................................................................. 125
11.3.13 Compliance with Water Framework Directive .............................................. 125
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LIST OF FIGURES
Figure 1.1
Greater Dublin Area / Dublin Region (Water Supply Area) ............................................... 3
Figure 1.2
Project Milestones 1996 – 2010 ........................................................................................ 8
Figure 1.4
Minimum & Maximum Water Demand Growth Scenarios (Average Demand) ............... 17
Figure 1.5
Peak Demand Growth Scenarios (incl Headroom provision) .......................................... 18
Figure 1.6
GDA Historic Population Growth (1961 – 2009) & Projections (2009 – 2031)................ 21
Figure 1.7
Water Supply Options...................................................................................................... 22
Figure 1.8
Desalination Option Schematic........................................................................................ 23
Figure 1.9
Multi Criteria Analysis & Strategic Environmental Assessment....................................... 24
Figure 1.10 Option Evaluation & Selection Process ........................................................................... 26
Figure 1.11 Option F2 Northern Lough Derg & External Storage at Garryhinch ................................ 30
Figure 2.1
Minimum & Maximum Average Water Demand Growth Scenarios................................. 42
Figure 2.2
Peak Demand Growth Scenarios (incl Headroom provision) .......................................... 43
Figure 2.3
New Source Supply Phases ............................................................................................ 45
Figure 2.4
Water Production Sources 2009 – 2040.......................................................................... 46
Figure 3.1
Timing of Supply Requirements from New Source.......................................................... 52
Figure 5.1
Water Supply Options Summary ..................................................................................... 57
Figure 6.1
Lough Ree Options.......................................................................................................... 63
Figure 7.1
Lough Derg / Parteen Basin Options............................................................................... 70
Figure 7.2
Lough Derg ...................................................................................................................... 70
Figure 7.3
Killaloe / Parteen Basin / Parteen Weir ........................................................................... 71
Figure 7.4
Parteen Weir .................................................................................................................... 72
Figure 7.5
Ardnacrusha Hydropower Station.................................................................................... 73
Figure 7.6
Headrace to Ardnacrusha................................................................................................ 73
Figure 7.7
Existing Average Flows and Abstractions ....................................................................... 75
Figure 7.8
Schematic of Average Water Flows Lough Derg / Parteen Basin................................... 76
Figure 8.1
Desalination / Groundwater / Liffey Barrow Options........................................................ 82
Figure 8.2
North Dublin Coastline (Potential location for siting Desalination Plant) ......................... 83
Figure 8.3
Typical RO Plant with Conventional Pre-treatment (for 100Ml/d).................................... 84
Figure 8.4
Groundwater Study Area (80km radius from Dublin)....................................................... 90
Figure 8.5
Schematic of Option J Operation..................................................................................... 96
Figure 8.6
Schematic of Water contribution from Liffey and Barrow ................................................ 96
Figure 8.7
Poulaphuca Reservoir ..................................................................................................... 97
Figure 8.8
River Barrow .................................................................................................................... 97
Figure 8.9
Liffey Catchment.............................................................................................................. 98
Figure 10.1 Option F2 Northern Lough Derg & External Storage..................................................... 117
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LIST OF TABLES
Table 1.1
Dublin Region Existing Water Supply Sources.................................................................. 4
Table 1.2
SEA Phase 2 Public Consultation – Stakeholder Presentations / Submissions ............. 12
Table 1.3
Minimum Planning Scenario ........................................................................................... 18
Table 1.4
Maximum Planning Scenario (SEA Phase 2) ................................................................. 19
Table 1.5
New Source Supply Requirements................................................................................. 19
Table 1.6
Capex / Opex / Whole Life Cost / Water Delivery Cost (2020 – 2045)............................ 31
Table 2.1
Average / Peak Demand (2010 – 2040) – Dublin Region (Water Supply Area) ............. 38
Table 2.2
Treated Water Production from Existing Sources ........................................................... 39
Table 2.3
Demand / Supply Balance (Mld) ...................................................................................... 40
Table 2.4
Minimum Planning Scenario ............................................................................................ 44
Table 2.5
Maximum Planning Scenario (SEA Phase 2) .................................................................. 44
Table 2.6
New Source Supply Requirements.................................................................................. 44
Table 4.1
Relationship between the Core Objectives of the Shannon RBMP and the WSP-DR Plan
......................................................................................................................................... 54
Table 4.2
Interaction of the WSP-DR Plan with the Action Programme of the Shannon RBMP..... 55
Table 4.3
Interaction of the WSP-DR Plan with the Other Issues of the Shannon RBMP .............. 55
Table 6.1
Modelling Results Summary ............................................................................................ 66
Table 6.2
Environmental Impact Summary of Lough Ree Options ................................................. 67
Table 6.3
Summary of Capital / Operating / Whole Life Costs ........................................................ 68
Table 7.1
Environmental Impact Summary – Option B – Lough Derg (No bog storage) ................ 78
Table 7.2
Environmental Impact Summary – Options F1 & F2 – Lough Derg + Storage ............... 78
Table 7.3
Environmental Impact Summary – Option C – Parteen Basin ........................................ 78
Table 7.4
Summary of Capital / Operating / Whole Life Costs ........................................................ 79
Table 8.1
Environmental Impact Summary Option H (Desalination)............................................... 85
Table 8.2
Summary of Capital / Operating / Whole Life Costs – Option H...................................... 86
Table 8.3
Conjunctive Use of Liffey (Poulaphuca) and Barrow ....................................................... 99
Table 10.1
Sustainability & Environmental Evaluation Rating Chart............................................... 108
Table 10.2
Habitats Directive Assessment (HDA) Rating ............................................................... 108
Table 10.3
Technical Assessment (Source) .................................................................................... 109
Table 10.4
Technical Assessment (Infrastructure) .......................................................................... 110
Table 10.5
Environmental Assessment (SEA) ................................................................................ 111
Table 10.6
Environmental Assessment (HDA) ................................................................................ 112
Table 10.7
Economic Assessment .................................................................................................. 113
Table 10.8
Socio – Economic Assessment ..................................................................................... 114
Table 10.9
Evaluation Summary / Ranking of Options.................................................................... 121
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APPENDICES
APPENDIX A
DEMAND APPENDIX
AA
Demand Projections 2009-2040
No. of Pages
1
AB
Demand Review
No. of Pages
147
APPENDIX B
Shannon Modelling Report
No. of Pages
51
APPENDIX C
Groundwater Report
No. of Pages
73
Appendix D
National & Regional Context for Plan / Project
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1 INTRODUCTION
The assessment of solutions for meeting the longterm water supply needs of the Dublin Region were
undertaken within the legislative framework of the Strategic Environmental Assessment (SEA)
Directive / Process. The SEA process (2006 – 2010) assessed the impacts of implementation of
various water supply options contained within a draft Plan. The draft Plan was prepared in conjunction
with specified Environmental Assessments and ‘Appropriate Assessments’ under the Habitats
Directive.
The draft Plan and Environmental Reports were tabled for public consultation under the SEA process
and feedback from the consultations were incorporated, as appropriate, into the draft Plan. The SEA
process requires that the Plan (amended draft Plan) is adopted by the ‘Competent Authority’ which
initiated the SEA– in this case Dublin City Council (DCC). Following adoption, an SEA Statement is
published outlining the rationale for the recommendations in the Plan and how environmental
considerations were accommodated in arriving at the recommendations.
This (adopted) Plan has emerged from extensive feasibility studies involving assessments of the
extent and timing of new supply needs in the Dublin, Mid East and Midlands Regions and options for
meeting those needs. Extensive consultation with a wide range of stakeholders, under the SEA
process, have led to the selection of a recommended solution for meeting longterm water supply
needs in an environmentally sustainable manner which ensures that the development of the new
supply minimises negative impacts on all communities – this has been a key guiding principle of all the
assessments to date and will continue to be the guiding principle as more detailed studies are
undertaken on the recommended solution during the next stage of the project’s development –
Environmental Impact Assessment (EIA) and Planning involving the independent planning body An
Bord Pleanála.
This Plan acknowledges the significant input of all who have contributed to date during the SEA
consultative phases, and DCC / RPS look forward to ongoing contributions from statutory & nonstatutory stakeholders as detailed consultations continue through the next stage of project
development – the EIA and planning stages.
1.1
BACKGROUND
Under the 2002 – 2004 Water Services Investment Programme (WSIP)*, Dublin City Council (DCC)
were appointed by the Department of Environment Heritage and Local Government (DEHLG) in 2003
to undertake Feasibility Studies and prepare a Plan / Report for the purpose of identifying and
recommending a preferred new major supply source to meet the longterm water supply needs of the
Dublin Region (Water Supply Area).
In carrying out the study, DCC act in a lead role on behalf of the seven Local Authorities in the Dublin
Region (Water Supply Area) who receive their water supplies (in whole or in part) from existing
sources and water treatment plants in the Region controlled and operated by DCC and / or Fingal
County Council.
Following a competitive procurement process an experienced international joint venture (JV)
consultancy organisation, RPS – Veolia JV, were appointed by DCC (2004) to undertake the
Feasibility Studies and prepare the Plan / Report. The JV was lead by RPS. SEURECA, an
international water consultancy organisation, wholly owned by Veolia Water, provided specialist inputs
and international project references by means of which the proposals for the Dublin Region were
benchmarked.
*The WSIP is prepared by the Department of Environment Heritage and Local Government (DEHLG).
The programme evolves from needs assessments received from all 34 Water Services Authorities in
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Ireland. Accordingly, the WSIP programme represents a balanced national strategic programme of
works designed to support the national socio-economic objectives established by Government in the
National Development Plan and related Plans & Policies.
1.2
RELEVANT NATIONAL POLICY FRAMEWORK
The National Policy context for this Plan would reference:
x
Economic Policy; based on the National Development Plan, the National Spatial Strategy and
the Governments policy towards developing ‘The Smart Economy’
x
Environment and Water Resource Management; through the implementation of the Water
Framework Directive (WFD) under the River Basin District (RBD) management programme
overseen by the Department of the Environment Heritage and Local Government (DEHLG)
x
Water Service Delivery; with reference to the Water Services Act (2007) and the Water
Services Investment Programme (WSIP) of the DEHLG for 2010-2012
x
Planning; through the Planning and Development Act 2000, the Strategic Infrastructure Act,
regional and local Development Plans
x
Environmental Assessment & Protection ofHabitats; through the Strategic Environment
Assessment (SEA) Regulations, Environmental Impact Assessment (EIA) Regulations,
Habitats Directive and other relevant environmental protection legislation (European and
National).
For further details in relation to the National context within which this Plan / Project fits see Appendix
D.
1.3
DUBLIN REGION (WATER SUPPLY AREA)
The Dublin Region (Water Supply Area) is outlined in Figure 1.1. It includes the administrative areas
of Dublin City, Dun Laoghaire-Rathdown, Fingal and South Dublin Counties, along with significant
parts of Counties Wicklow, Meath and Kildare. Current population (2010) of the Dublin Region (Water
Supply Area) is approx 1.5m people.
The Greater Dublin Area (GDA) includes the administrative areas of Dublin City, Dun LaoghaireRathdown, Fingal, South Dublin and all of Kildare, Meath and Wicklow.
Table 1.1 outlines the existing Dublin Region sources including the sustainable outputs from the water
treatment plants which treat water (to drinking water) standard from these sources.
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Greater Dublin Area / Dublin Region (Water Supply Area)
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Table 1.1
The Plan
Dublin Region Existing Water Supply Sources
Water Treatment Plant
Sustainable
Output
Licence
Ballymore Eustace WTP
(2010)
318Mld*
In place since 1940 and reviewed periodically in
light of changing needs. Abstractions from
Poulaphuca Reservoir are regulated under longterm (historic) agreements with the ESB and are
managed by ESB as part of overall dam
management.
Leixlip (2010)
148Mld
In place since the 1960’s. Abstraction is through
agreement with ESB and managed by ESB as
part of overall dam management.
Planned Output (2014)
215Mld
Roundwood
75Mld
The Vartry abstraction has been in place since
1870. The abstraction was covered under the
1861 Dublin Corporation Waterworks Act which
enabled the Corporation to acquire the entire
waterway, a bill was passed to allow this and to
allow the Corporation to build the reservoir and
provide them with the ability to buy land similar to
the CPO procedures which Local Authorities now
use.
Ballyboden (Bohernabreena)
16Mld
Abstractions from Bohernabreena have been in
place since the 1880’s. Abstraction from
Boherbreena reservoir was set up by the
Rathmines and Pembroke township in the 1880’s
to supply that area. This township was dissolved
in 1932 and Dublin Corporation took over the
management of this supply.
Bog of the Ring
3Mld
An ongoing monitoring programme was put in
place by Fingal Co Co to establish the
sustainable levels of abstraction (approx 3.0 Mld).
Total Sustainable Water
Availability from Existing
Dublin Region sources
627Mld
*1Mld = 1 million litres per day or one thousand cubic metres (m3) per day
1.4
HISTORICAL CONTEXT
The first significant public water supply to Dublin and Wicklow was the Vartry scheme constructed in
the 1860s by the then Dublin Corporation (now Dublin City Council (DCC)) and remains in service over
130 years later. This scheme with its source at Roundwood includes a rock tunnel feeding twin trunk
mains to the city and incorporates open storage reservoirs at Stillorgan. It replaced private water
supplies, generally from groundwater sources. These had become polluted and were a major source
of waterborne diseases that caused regular epidemics.
Also in the 19th century, the Dodder scheme at Bohernabreena was also developed by Dublin City to
supply the Rathgar/Pembroke area, with facilities for treatment at Ballyboden.
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During the 1940s, the Electricity Supply Board (ESB) (a commercial semi state organisation) in
conjunction with Dublin Corporation (now DCC) developed a joint venture scheme to provide dams at
Poulaphuca and Leixlip on the River Liffey, which impounded water for power generation and for
public water supplies. Water treatment plants were built initially at Ballymore Eustace and later at
Leixlip. These were further developed and expanded over time as supply needs grew.
Poulaphuca Reservoir
Leixlip Reservoir
The Vartry and Liffey schemes (which were visionary in their day), developed for the benefit of the
Region by Dublin City, ensured long-term secure supplies of high-quality water for Dublin. They
enabled its economic development and growth for over a century. Both schemes required the
construction of significant infrastructure to convey water to locations which in many instances were
over 50km from source. For their day, they were major engineering and economic feats.
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Vartry Reservoir and Roundwood Water Treatment Plant
As in the past, the Dublin Region is again approaching the stage where new long-term secure and
sustainable supplies of water are critical to the next phase of its development, in order that it can
continue to grow and contribute to the optimal performance of the state as a whole - economically,
socially and environmentally - as envisaged in the National Spatial Strategy for balanced development
which is a key component of the overall National Development Plan. Current supply / demand
projections, which allow for the recession (2008 – 2010) and include for ambitious demand
management initiatives, strongly indicate that without supplies from a new major source of water, the
development of the region is likely to be constrained over the next 10 – 15 years. Delivery of a new
source of adequate size within this timeframe will be challenging.
1.5
OVER RIDING PURPOSE
The over riding purpose of this Plan is to:
x Assess the long-term water supply needs of the Dublin Region (Water Supply Area) in the
context of projected economic growth strategies for the region and current / projected water
supply & demand management initiatives
x Assess the need for future water supplies from a new source, the extent of the new supply
need and the optimal timing of the new supply need from technical & operational
perspectives
x Recommend a preferred new water supply scheme (to meet long-term water supply needs)
and evaluate the technical, environmental, economic and socio-economic (stakeholder)
aspects of the new scheme
x Evaluate & recommend procurement strategies and timelines for securing planning consent
and implementation of a potential new scheme
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The Plan
This (2010) Plan builds on the initial 2006 draft Plan (3 Water Supply Options), the first phase of
Strategic Environmental Assessment (SEA Phase 1 – 2006), public consultation in June / July 2006
and the subsequent adoption of SEA Phase 1 recommendations by Dublin City Council (Strategic
Policy Committee) which established the framework for the subsequent evaluations of Shannon,
Groundwater and Irish Sea (Desalination) sources as potential solutions for meeting the longterm
water supply needs of the Dublin Region.
This (2010) Plan also builds on the 2008 draft Plan which was tabled for public consultation during
SEA Phase 2 (Nov 08 – Feb 09) – the 2008 draft Plan included feasibility assessments of 10 Water
Supply Options identified during the SEA Phase 1 consultation process.
1.6
PROJECT DEVELOPMENT (1996-2010)
Figure 1.2 outlines the key milestones in the project’s development from the initial strategic study in
1996 (Greater Dublin Water Supply Strategic Study – GDWSSS 96) up to the present Preliminary
Report (2010).
Sections 1.6.1 to 1.6.5 describe in greater detail the key activities corresponding to the project
milestones in Figure 1.2.
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Figure 1.2
The Plan
Project Milestones 1996 – 2010
GDWSSS 1996 – Potential New Source Need Identified
YEAR 2000 Review of GDWSSS 96
Feasibility Study of 3 Options – 2004/5
Strategic Environmental Assessment (SEA) Phase 1 Jan – July 2006
3 Options – Formal Public Consultation (June 06 – July 06)
DCC Submission of Feasibility Study to DEHLG – August 2006
Additional Stakeholder Feedback Aug – Oct 2006
Recommendations SEA Phase 1 – Dublin City Council (Oct / Nov 2006)
Additional Shannon Options + Desalination Alternative
Feasibility Study of 10 Options – 2007/8
Draft Plan – 2008
SEA Phase 2 -2007/9
Environmental
Report
Habitats Directive Assessment
Report
Public Consultation – Draft Plan / Environmental Report / HDA Report
November 2008 – February 2009
Analysis of Public Consultation Feedback / Sustainability Assessments
Feb - Oct 2009
Recommended Option (Shannon Lough Derg + External Storage)
July 2010
Plan (Amended Draft Plan) – Recommended Option
DCC Adoption of Plan – October 2010
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1.6.1
The Plan
Greater Dublin Water Supply Strategic Study 1996 / Year 2000 Review
The potential need for a new water supply source for Dublin was first identified (officially) in 1996 as
part of a strategic study into the Dublin Region’s longterm water supplies, carried out by the
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The Plan
Department of Environment Heritage and Local Government (Greater Dublin Water Supply Strategic
Study 1996). This study was reviewed and updated in 2000 (Year 2000 Review) and three new supply
options were shortlisted for further study (Desalination / Shannon – Lough Ree / Liffey – Barrow). The
year 2000 review also recommended a reduction in leakage and development of existing Dublin
supply sources to their sustainable limits as priority recommendations ahead of the new source
proposal.
1.6.2
Feasibility Studies (3 Options) / SEA Phase 1 Stakeholder Consultations
A Feasibility Study of the three shortlisted options was carried out in 2005, followed by the first phase
of Strategic Environmental Assessment in 2006*. Formal public consultation (as required by SEA) took
place in June / July 2006. The Feasibility Study and SEA Phase 1 recommended that the Shannon
was preferable to Desalination / Liffey Barrow as a new supply source option and that the Lough Ree
Shannon location should be investigated in greater detail, in the first instance, on account of its closest
proximity to the Dublin Region. The Lough Ree recommendation was made subject to full
Environmental Impact Assessment (EIA) being required, including the necessity for detailed
hydrological modelling to identify with a high degree of confidence potential abstraction impacts on
lake levels and flows. The recommendation recognised that availability of adequate water in Lough
Ree for abstraction would require a significant degree of control of storage in the lake and that this
would have to be reconciled with other competing interests (power generation, leisure boats, flooding,
fisheries, etc). The need for a more detailed hydrological model was identified, in order to be able to
accurately assess alternative management strategies and to take account of climate factors.
*The Strategic Environmental Assessment (SEA) Directive (2001/42/EEC) was transposed into
national legislation in Ireland in July 2004. This legislation requires that certain Plans and Programmes
prepared by statutory bodies, which are likely to have a significant impact on the environment, be
subject to the SEA process. Article 3(2) of the SEA Directive makes SEA mandatory for plans and
programmes:
a) which are prepared for agriculture, forestry, fisheries, energy, industry, transport, waste
management, water management, telecommunications, tourism, town and county planning or
land use and which set the framework for future development consent for projects listed in
Annexes I or II of the Environmental Impact Assessment (EIA) Directive (85/337/EEC); or
b) which, in view of the likely effect on sites, have been determined to require assessment
pursuant to Article 6 or 7 of the Habitats Directive (92/43/EEC).
1.6.3
SEA Phase 1 Additional Stakeholder Consultations
Following on from formal SEA public consultation in June / July 2006, further consultation continued
(August – October 2006) primarily with the (recently formed) statutory Shannon International River
Basin District Advisory Council (ShIRBDAC) and non-statutory Shannon Protection Alliance (SPA).
Both of these groups represented practically all Shannon stakeholders and enabled a more focused
approach to stakeholder engagement than had been available during earlier stakeholder consultations
as part of the Feasibility Study and SEA Phase 1 formal public consultation process.
Between August & October 2006, many new issues arose in relation to the general lack of consensus
among stakeholders concerning the existing management & operation of the Shannon (by statutory
operators ESB and Waterways Ireland). These issues were more numerous and detailed than the
feedback issues which had emerged during the SEA Phase 1 formal public consultation period in June
/ July 2006. The stakeholder feedback particularly underlined the lack of consensus between
navigation interests and riparian landowners in relation to water levels (flooding) in Lough Ree and
downstream on the Shannon Callows. As a result, the controls and operational changes (at Athlone
Weir), necessary to enable 350Mld to be abstracted from Lough Ree could not be relied upon with a
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sufficient degree of certainty. Without these controls prioritised for water abstraction, the required
capacity could not be guaranteed as being available for Lough Ree.
1.6.4
Dublin City Council – Strategic Policy Committee / Expanded Range of
Options
During August – October 2006, DCC and its advisers (RPS) concluded that the range of options which
had been considered during SEA Phase 1 was too narrow and that further studies (including
appropriate modelling support) involving a wider range of options were required to identify the
optimum solution to the Dublin (& Mid East) Region’s impending water supply problems.
In October / November of 2006, the Strategic Policy Committee of Dublin City Council accepted the
recommendations which emerged from the first phase of Strategic Environmental Assessment. They
agreed that additional Shannon / Groundwater options should be investigated in greater detail and
also stipulated that the Desalination Option was to be investigated at the same level of detail as the
Shannon options.
The wider range of options (identified from the stakeholder feedback) included Lough Derg, Parteen
Basin, use of external storage (cutaway bogs) and potential groundwater options in addition to a more
proactive programme of leakage management and water conservation. As a consequence of the
extensive stakeholder feedback, the initial range of options (3 No) was expanded by an additional 7
No options bringing the total for consideration to 10 No.
1.6.5
Feasibility Studies (10 Options) / SEA Phase 2 / Public Consultation
Feasibility Studies of the expanded range of options were carried out in 2007 & 2008 including
extensive consultations with statutory stakeholders. A second phase of Strategic Environmental
Assessment (SEA Ph2) commenced in early 2008.
Formal public consultation (as required by the SEA process) took place from November 2008 to
February 2009 on the expanded range of potential water supply options. Information in relation to the
project was lodged in hardcopy format in 17 Local Authority libraries and all data was made available
digitally via a dedicated project website. The public were informed of the availability of project data via
newspaper advertisements in the Irish Times, Irish Independent and Belfast Telegraph on 22
November 2008. During the public consultation period, 31 presentations were made to a wide variety
of stakeholders and considerable feedback was received in subsequent ‘Question & Answer’ sessions
which were minuted and recorded. The dedicated project website registered in excess of 2,500 ‘hits’.
At the end of the formal public consultation period on 27 Feb 2009, in excess of 50 formal submissions
(written & email) had been received from stakeholders and the general public (see Table 1.2).
Over the consultation period, regular interviews with local radio stations and local newspapers (in the
Shannon Catchment Area and in Dublin) also assisted in informing the public on the progress of the
studies and advised of the availability of project details in newsletters / Local Authority libraries and on
the dedicated project website.
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Table 1.2
SEA Phase 2 Public Consultation – Stakeholder Presentations / Submissions
- An Taisce
- Birdwatch Ireland
- Bord na Mona
- Border Midland and Western
Regional Assembly
- Brian Pope (member of public)
- Chamber’s Ireland
- Claire Wheeler – Green Party
- Clare County Council (Clare Co
Co)
- Dublin City Council Strategic
Policy Committee (SPC)
- Department of Communications,
Energy and Natural Resources
(DCENR)
- Department of Environment,
Heritage and Local Government
(DEHLG)
- DEHLG (National Parks and
Wildlife Service)
- Dun Laoghaire Rathdown Co Co
(DLRCC) SPC
- DEHLG (The architectural
heritage advisory unit, The
archaeological underwater unit
and the national monuments
unit)
- Dublin City Business Association
(DCBA)
- Dublin Tourism
- Eastern Regional Fisheries
Board (ERFB)
- Environmental Protection
Agency (EPA)
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- Electricity Supply Board (ESB)
- Fáilte Ireland
- Fintan Donnelly (member of
public)
- Galway Co Co
- Galway Co Co SPC
- Geological Survey of Ireland (GSI)
- GMC Contractors
- Golden Eagle Trust
- Hugh Lee (member of public)
- Irish Business and Employers
Confederation (IBEC)
- Irish Farmers Association (IFA)
- Irish Hotels Federation
- Inland Waterways Association of
Ireland (IWAI)
- James Fenwick (former Dublin City
Engineer)
- John McGinley (member of public)
- Ken Irvine (Environmental Expert)
- Kildare Co Co SPC
- Lansdowne Road Developments
- Laois County Council
- Lisheen Mines
- Longford Co Co
- Longford Heritage Forum
- Lough Derg Anglers Association
- Lough Derg Science Group
(LDSG)
- Lough Derg Science Group,
Shannon IRBD and Limerick
County Council
- Mid East Regional Authority
12
- Mid West Regional Authorities
- Midlands Regional Authority
- North Tipperary SPC
- Northern Ireland Environment
Agency
- Offaly Co Co
- Roscommon County Council
- Shannon International River Basin
District (ShIRBD) Advisory Council
Members
- ShIRBD Management and
Steering Group
- ShIRBD - Included copies of
Submissions from SWAN
(BirdWatch Ireland rep),SWAN
(SOLD and VOICE rep), IFA
representative and Chairman of
the Advisory Council
- ShIRBD - Limerick Co Co
- Shannon Protection Alliance
- Shannon Region Fisheries Board
(ShRFB)
- Sinn Fein – Dublin
- Sinn Fein – Nenagh
- Sustainable Development Ireland
- Sustainable Water Network
(SWAN) (SOLD and VOICE rep)
- The Heritage Council
- Warren Whitney (member of
public)
- Waterways Ireland
- West Regional Authority
- Westmeath Co Co
- Wine Board Ireland
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1.6.6
The Plan
Selection of Recommended Option / Stakeholder Feedback
Feedback from the SEA Phase 2 public consultation process, technical,environmental and economic
analyses (sustainability assessments) resulted in the recommendation of a preferred water supply
option for the Dublin & Mid East Regions (Northern Lough Derg + External Storage) – see Section
1.11. This Plan recommends that this option be brought forward into the formal planning process
involving An Bord Pleanála which is the next stage in the overall development of this project.
The Plan incorporates relevant SEA stakeholder feedback which arose from public consultation and
the findings of the SEA Environmental Report and HDA Report. As a result of the extensive feedback
and changed circumstances since 2008 (economic conditions and proposed government domestic
metering & charging policies), this Plan re-visits assumptions in the 2008 draft Plan in the following
areas;
x Population projections (2010 – 2022 Regional Planning Guidelines)
x Levels of personal water consumption (per capita consumption – pcc) in light of the
impending introduction of domestic water metering & volumetric charging (new Government
policy)
x Reduced levels of customer leakage (domestic water metering & volumetric charging)
x Distribution network leakage through active leakage management and ongoing network
rehabilitation programmes
x Reduced non-domestic water demand (economic downturn)
x Various technical & environmental issues which arose as part of the option evaluation
process
A comprehensive account of all issues raised in relation to the 2008 Draft Plan during SEA public
consultation is available in the Public Consultation Report on the dedicated project website ;
www.watersupplyproject-dublinregion.ie / publicconsultationreport.
1.7
NEED FOR PROJECT
1.7.1
Government Economic Growth Policy
High level Irish Government policy in relation to economic growth is set out in the National Spatial
Strategy (NSS) and National Development Plan (NDP). Both of these policy documents recognise
that national economic-growth objectives will continue to require managed development of the
Greater Dublin Area (GDA) / Dublin Region to its full potential. The Greater Dublin Region is the key
economic driver of the country as a whole, with over 50% of economic growth generated there.
Economic growth objectives are provided for in the (Dublin & Mid East) Regional Planning Guidelines
(2010 – 2022), supported by Development Plans in each Local Authority area within the Regions.
The planned growth objectives in the Dublin & Mid East Regions as envisaged in the (2010 – 2022)
Regional Planning Guidelines and National Spatial Strategy form the basis for estimating the extent
of water availability which must be provided for, in order to sustain these economic growth targets.
These longterm growth forecasts take account of high and low / negative growth economic cycles
and extend the consistent longterm growth patterns for the Regions since 1960 (see Figure 1.5).
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1.7.2
The Plan
Headroom / Security of Supply
Demand for treated water in the Dublin Region (Water Supply Area)
currently exceeds the sustainable production capability of the existing
water treatment plants at Ballymore Eustace, Leixlip, Roundwood and
Ballyboden. As a consequence, these plants are being operated in an
unsustainable manner in order to meet day to day demand
requirements. This ‘knife – edge’ operational regime and lack of
‘headroom’ availability in the Region presents an ever increasing risk to
continuous supply availability, particularly from supply network failure, as
critical infrastructure components cannot be taken out of service and
upgraded as appropriate. Availability of adequate headroom is essential
for servicing the needs of future industrial and other employment led
demand in the Region as the economy recovers. Such headroom forms
an essential component of water supply infrastructure for comparable
conurbations in Europe and other developed countries. The extended
cold spell experienced in Dublin (January 2010) gave rise to water
shortages as a result of short term demand increases in conjunction with
a lack of headroom capacity in the supply system. This has underlined
the vulnerability of the supply in the absence of a new major source for
the Region. Water supply management in the Region (pending the
arrival of supplies from a new source) will continue to be at risk from lack of adequate headroom
capacity.
1.7.3
Water Demand Growth
Whilst operating with little or no headroom, demand growth over the past decade in the Dublin Region
has largely been met by water savings from leakage management, water conservation initiatives,
incremental expansion of Ballymore Eustace water treatment plant and operation of all treatment
plants beyond their sustainable production capacities. Short term future demand growth will continue
to require further aggressive water savings from sustained leakage management and water
conservation, including planned network rehabilitation, in combination with additional water availability
resulting from the expansion of Ballymore Eustace and Leixlip water treatment plants to their
maximum sustainable limits. The scale of increased water availability from these initiatives, however,
will at best maintain the status quo taking account of the likely increasing short term water demand
growth in the Region. The increased water availability from these initiatives will not address the lack of
strategic ‘headroom’ capacity in the Region and will do nothing to reduce vulnerability to short term
contingencies (water demand increases resulting from severe climatic conditions or reduced
production output resulting from outages).
1.7.4
Demand / Supply Projections 2009 - 2040
The assessments of long term water supply needs for the Dublin Region were carried out in the
context of best practice water conservation measures being implemented within the region. Between
1996 and 2002, leakage was reduced from 42% to 28% primarily through active leakage management
programmes. Reducing leakage levels below 28% requires ongoing sustained network rehabilitation –
a substantial replacement programme (costing €120m) began in 2007. Metering of all non domestic
water supplies was completed in early 2009 and planning has commenced in relation to extending
metering to all domestic consumers and achieving the benefits of use related charging for water within
the next 5 – 10 years, in line with indications signalled by Government in draft Budget 2010 with
respect to metering and volumetric charging for domestic water supplies.
The analysis of projected water demand growth in the Dublin Region for the 2010 – 2040 period, has
built on the findings of the DEHLG 1996 and 2000 studies updated to take account of the proposed
policy to meter all customers (domestic as well as non-domestic) and to optimise water management.
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Two demand scenarios have emerged from the projected demand growth analyses – Maximum
Planning Scenario & Minimum Planning Scenario.
The ‘Maximum Planning Scenario’, was prepared in 2007 for Phase 2 of the Strategic Environmental
Assessment process. The significant growth in water demand which occurred between 1996 and 2007
was largely met by increased production from existing sources combined with operational initiatives to
reduce leakage. The 2007 demand forecasts largely concentrated on a continuation of this approach
with a strong emphasis on network rehabilitation and active leakage control programmes with demand
management strategies limited to customer awareness programmes, building bye-laws, promotion of
water efficient appliances and 100% metering of the non-domestic sector.The need for / timing of
potential supplies from a new source were evaluated against this background with lower emphasis on
extensive domestic demand management initiatives in the absence of policies requiring domestic
metering & charging.
This situation changed significantly in the latter half of 2009, with the publication of draft Budget 2010,
which signalled proposed changes to Government Policy in relation to domestic metering and
volumetric charging for water. The 2007 demand projections were revised in 2009 /10 to take account
of the proposed Domestic Metering & Charging Policy changes (see Appendix A). A ‘Demand Review’
report was prepared (see Appendix AB) in order to inform the Plan of the impacts which could be
anticipated on demand growth from the proposed policy changes. The Demand Review identified a
‘Minimum Achievable’ scenario which forms the basis for the ‘Minimum Planning Scenario’ on
which the recommendations in this Plan are based.
The ‘Minimum Achievable’ / ‘Minimum Planning Scenario’ assumes that best practice water
conservation measures are being implemented in the Dublin Region in advance of the introduction of
any supplies from a new source. Domestic demand growth forecasts assume that personal
consumption is reduced by up to 15% as a result of the proposed policy changes. Customer leakage is
reduced by up to 70%. Distribution system leakage is reduced from 29% to 20% through active
leakage management and network rehabilitation. Forecast non domestic demand growth rates are
reduced by up to 30% to reflect the current economic slowdown (2008 – 2010).
The targeted water savings for the Minimum Planning Scenario scenario are ambitious considering
Dublin’s starting position, nevertheless they have been assessed as potentially achievable within
acceptable budgetary and implementation risk constraints. This scenario is regarded as the ‘best
practical environmental & economic scenario’ and is recommended in this Plan as the scenario on
which planning for the development of a new water supply is based. Details of the Minimum Planning
Scenario demand projections are contained in Appendix A. Appendix AB contains detailed reviews of
various demand components including international ‘best practice’ comparisons and looks at cost / risk
implications for extensive demand management initiatives.
The detailed supply / demand assessments (Chapter 2 & Appendix A), also include updated estimates
of sustainable production from existing Dublin Region sources.
Approx 85% of Dublin’s water is abstracted from two
locations on the River Liffey. Water abstracted from
Poulaphuca on the Upper Liffey is treated at Ballymore–
Eustace Water Treatment Plant (BME WTP) and water
abstracted from Leixlip on the Lower Liffey is treated at
Leixlip Water Treatment Plant (WTP). The remainder of
the Region’s supply is abstracted from the River Vartry
and River Dodder and some groundwater sources in
Fingal and Kildare (Kildare’s dependence on Dublin supply
sources will reduce by 10Mld – 20Mld with the
development of a new Barrow source). All of these existing
sources (particularly BME & Leixlip) are currently being
developed to their sustainable supply limits estimated at approx 627Mld (see Chapter 2 & Appendix
A). Existing sources are anticipated to be fully developed by approx 2013 /14 (with the completion of
Leixlip WTP expansion).
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The sustainable production levels of BME, Leixlip, Roundwood and Ballyboden Treatment Plants are
based on the historical capacity of the (Liffey, Vartry, Dodder) sources and make no allowance for
projected reduced Summer flows due to Climate Change effects (see Section 1.7.8). Such effects in a
dry Summer could reduce the level of sustainable abstractions available for the Region.
In summary, projections based on realistic supply capabilities and ambitious demand management
targets predict that supplies from a new supply source are highly likely to be required (by 2020 latest)
to ensure guaranteed supply availability into the future and satisfy the future needs of projected
population and economic growth in the Region. These ambitious projections have a certain amount of
risk which must be managed and any assumption that the projected scenario would occur over a
longer period carries a very high level of risk that is likely to be unacceptable from a strategic planning
viewpoint.
1.7.5
Timing of New Supply Requirements
As outlined in Section 1.7.4, two principal Demand Planning Scenarios emerged from the demand
analyses (‘Minimum Planning Scenario’ & ‘Maximum Planning Scenario’).
The ‘Minimum Planning Scenario’ is the recommended Planning Scenario as it entails an overall
integrated water resource management solution for the Dublin Region. This type of approach was
advocated in much of the SEA public consultation stakeholder feedback which is fully accounted for in
this scenario. The Minimum Planning Scenario main assumptions are summarised as follows;
-
Full introduction of Domestic Metering & Charging by 2020 – 2022
-
Reductions of up to 20% in personal usage (resulting from metering &
charging)
-
Reductions of up to 70% in customer leakage (resulting from metering &
charging)
-
Promotion of best practice demand management including bye-laws to
encourage low water use
-
Reductions in Distribution Network Leakage (Network Rehabilitation & Active
Leakage Control) to 20% by 2040 from 29% (2010)
-
Low to Medium Economic Growth (all zoned lands developed by 2040 as
opposed to original SEA proposal of 2031)
In the Minimum Planning demand growth scenario, supplies from a new source will be required by
(latest) 2022 when ‘average day’ demand equals the sustainable production capacity of existing
sources (627Mld). The timing of new supply requirements for this scenario is illustrated (solid green
line) in Figure 1.3 If planned leakage targets or savings from reduced personal consumption
experience slippage, then the demand projections represented by the ‘solid green line’ will move
backwards towards the ‘red line’ necessitating an earlier need for water supplies from a new source.
In the Maximum demand growth scenario (prepared in 2007 for Phase 2 of the Strategic
Environmental Assessment process) involving medium to high economic growth rates and limited
savings from demand management, water conservation measures & leakage management, supplies
from a new source could be required as early as 2016 (coloured red) in Figure 1.3.
In order to plan prudently for potential slippages in achievement of water savings from leakage
reductions and water conservation, this Report recommends that planning commences now in order to
ensure that supplies from a new source can be made available from 2020 onwards. This date
represents the most likely ‘earliest delivery date’ for the project, assuming the planning process
commences in 2010 (Planning Process 4 years / Procurement 2 years / Construction 4 years).
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Figure 1.3
The Plan
Minimum & Maximum Water Demand Growth Scenarios (Average Demand)
850
Maximum Planning Scenario
(SEA Phase 2)
800
750
Minimum
Planning Scenario
Earliest Delivery Date
700
50Mld Headroom
650
Mld
Unsustainable
Production
Sustainable Production
600
550
Barrow Supplies on stream
500
450
400
2006
2008
2010
2012
2014
2016
2018
2020
2022
2024
2026
2028
2030
2032
2034
2036
2038
2040
Year
Minimum Planning Scenario
1.7.6
Maximum Planning Scenario (SEA Phase 2)
Headroom
Peak Demand & Headroom Allowances
Demand growth projections in Figure 1.3 are based on ‘Average Demand’. Management of water
demand also requires that sufficient production & storage capacity is available to meet peak demands
at certain times of the year and that sufficient excess capacity (headroom) is also available to cater for
infrastructure failure / plant outages / pollution incidents (eg cyrptospiridium) etc.
The ‘Demand Review’ contained in the Demand Report (Appendix AB) considered four demand
growth scenarios;
x Do Nothing
x Maintain Current (Equivalent to SEA Phase 2 - ‘Maximum Planning Scenario’)
x Minimum Achievable (Equivalent to ‘Minimum Planning Scenario’)
x ‘Theoretical Minimum’ scenario. This scenario effectively identified each component
of demand (domestic / non domestic / leakage / headroom etc) and ‘cherry-picked’
best practice for each demand component across a range of international water
companies. These best practice projections were then applied to the Dublin Region
growth projections.
Figure 1.4 illustrates the four scenarios for peak demand including provision for headroom based on
international best practice. The graph identifies that even for the ‘Theoretical Minimum’ scenario,
supplies from a new source would still be required in the early 2020’s in order to manage peaks and
have adequate headroom in place.
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Figure 1.4
The Plan
Peak Demand Growth Scenarios (incl Headroom provision)
Peak Water Demand Scenarios
1400
1250
1200
1053
1000
942
800
Mld
742
627
600
400
200
0
2010
2012
2014
2016
2018
2020
2022
2024
2026
2028
2030
2032
2034
2036
2038
2040
Year
Theoretical Minimum
1.7.7
Minimum Achievable
Maintain Current
Sustainable Production = 627Ml/d
Do Nothing
New Source Supply Requirements
Dublin Region average demand projections have been estimated (Table 1.3 & Table 1.4) for the
Minimum & Maximum demand growth scenarios as follows;
a) The Minimum Planning Scenario – 800Mld average demand reached at 2040
Table 1.3
Minimum Planning Scenario
Dublin Region
(Water Supply
Area)
1996
2008
2010
2016
2022
2031
2040
Average Total
Demand (MId)
460
540
545
580
621
700
800
Max. Production
of Dublin Region
Sources (MId)
470
560
580
627
627
627
627
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b) Maximum Demand Growth (SEA Ph 2 Scenario) – 800Mld average demand reached at 2031
Table 1.4
Maximum Planning Scenario (SEA Phase 2)
Dublin Region
(Water Supply
Area)
1996
2008
2010
2016
2022
2031
2040
Average Total
Demand (MId)
460
540
545
627
670
800
N/A
Max. Production
of Dublin Region
Sources (MId)
470
560
580
627
627
627
N/A
Maximum Sustainable Production (2014 onwards) of existing Dublin Region sources is 627Mld
Supply requirements from a new source have been calculated as shown in Table 1.5.
Table 1.5
New Source Supply Requirements
Average Supply Requirements (at 2031 / 2040) = 800 Mld – 627 Mld
=
173 Mld
Additional Peak Requirements (at 2031 / 2040)
=
80 Mld
Supply Allowance for Midlands Local Authorities
=
50 Mld
Headroom (Contingency) Allowance
=
50 Mld
=
353 Mld
Supply (new source) Total
(say 350Mld)
1.7.8
Climate Change / Security of Supply
Climate change analyses for the East of Ireland project rainfall increases in Winter (+10% to +20% for
2010 – 2039) and reductions in Summer (-20% to -40% for 2010 – 2039). Projected increases /
reductions in Winter / Summer rainfall for Ireland East have been advised by climate experts at NUI
Maynooth (ICARUS). Raw water storage facilities at Poulaphuca and Roundwood have some limited
potential for offsetting Winter rainfall increases against Summer rainfall reductions but the net effect of
climate change in the East of Ireland will result in a long term gradual reduction in the sustainable yield
of existing Dublin Region sources.
Ireland generally, and the East in particular, have had a series of wet summers in recent years and
consequently, raw water shortages in the Region, as a result of climatic factors, have not arisen.
However, there is little doubt that if a 1975 / 76 or 1995 type drought weather pattern re-emerged in
the East before supplies from a new source become available, significant water shortages, particularly
in the Liffey, could occur, leading to a return of water rationing and restrictions. A new supply source is
necessary to ensure that this situation does not materialise.
In almost all years, Poulaphuca reservoir fills to its maximum operating level (consistent with
managing flood risk) during the winter / spring season. This sustains summer river flows and
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The Plan
abstraction levels. Climate change could adversely impact on water availability for Dublin from the
Liffey in a number of ways:
x
Increased winter rainfall could lead to lower lake operating levels to manage flooding risk,
leaving less water in storage
x
Dryer summer weather could increase losses (evapotranspiration) depleting resources faster
through the season
x
Dryer summers would be likely to place upward pressure on water demands
1.7.9
Economic Downturn (2008 – 2010)
The current (2008 – 2010) downturn in the economic cycle has resulted in lower demand growth rates
for 2008 / 09 which may continue into 2010. These short-term decreases must be viewed against a
background which identifies clearly that water demand growth in the Dublin Region has increased in
line with population growth for over 50 years. During this period many economic cycles have been
experienced, with water demand patterns mirroring economic growth rates, but longterm water
demand growth has continued at a consistent 1% - 2% underlying annual growth rate.
Figure 1.5 shows historic growth in Greater Dublin Area (Dublin & Mid East Regions) population from
1961 to the present and projections for 2009 to 2031. The population growth line and associated
water consumption growth line for the 1961 to 2009 period show the same continuously increasing
trend.
Three Central Statistics Office (CSO) population projections are illustrated for the 2009 – 2031
period.
1) M0F1 Traditional
2) M2F1 Traditional
3) M2F1 Recent
M0 = Net International Migration & Emigration = 0
M2 = Net International Migration & Emigration declining but greater than zero
F1 = Current fertility rates (births / deaths)
Traditional = Internal Migration (into Dublin Region from within Ireland) prior to 1996
Recent = Internal Migration (into Dublin Region from within Ireland) between 1996 & 2008
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Figure 1.5
The Plan
GDA Historic Population Growth (1961 – 2009) & Projections (2009 – 2031)
GDA Population Growth 1961 - 2009 &
CSO Projections 2009 - 2031
Population (1000's)
3000
2500
2000
1500
1000
500
1.8
2026
2021
2016
2011
2006
2001
Projected 2031
M - International Migration Scenarios
F - Fertility Rates
Recent / Traditional - Internal Migration Scenarios
1996
1991
1986
1981
1976
1971
1966
1961
0
Year
Population GDA (historic)
Population GDA (projected) - M2F1 Recent
Population GDA (projected) - M0F1 Traditional
Population GDA (projected) - M2F1 Traditional
National Spatial Strategy
WATER SUPPLY OPTIONS
The Year 2000 Review of the Greater Dublin Water Supply Strategic Study (1996) identified three
potential new source options for investigation with a view to assessing their potential for supplying the
Dublin Region with secure sustainable longterm water supplies. Following Feasibility Studies (2005),
these three options were tabled for public consultation within the SEA Phase 1 process in 2006.
Feedback from public consultation resulted in Dublin City Council agreeing to include a wider range of
water supply options (10 No) in follow - up Feasibility Studies during 2007/8. The ten options which
were considered in detail as potential new supply sources for the Dublin Region are outlined
schematically in Figure 1.6. Chapter 5 provides greater detail in relation to the (10 No) potential water
supply options.
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Figure 1.6
The Plan
Water Supply Options
A-Lough Ree
C-Parteen Basin
E- Lough Ree
+ Storage
G-Impoundment
- Lough Ree [Derg]
I-Fingal / Kildare
Groundwater
B-Lough Derg
D-Lough Ree +
Lough Derg
F- Lough Derg
+ Storage Options
H-Desalination
J-Liffey / Barrow
MULLINGAR
Lough
Ree
Desalination Plant
H
Wells
A
ATHLONE
G
I
Ballycoolen
E
E
D
F1
Termination
Point
Former Bogs
TULLAMORE F
2
River
Shannon
G
Impoundment
Ballymore Eustace
F
Lough
Derg
Parteen
Basin
Head
Race
Poulaphuca Lake
B
SLIEVE BLOOM
MOUNTAINS
J
PORTLAOISE
Athy
River
Barrow
Killaloe
C
Water Treatment Plant
MDW0158SK0036D14
River Shannon
ESB Ardnacrusha
1.8.1
River Shannon Water Supply Options
Of the ten (10) water supply options which were considered, seven (Options A to G) have Shannon
storage locations as their water supply source. These options are:
A. Lough Ree (Direct)
B. Lough Derg (Direct)
C. Parteen Basin (Direct)
D. Lough Ree and Lough Derg (Phase 1 Abstraction Lough Ree (250Mld) followed by Phase
2 (100Mld) Lough Derg)
E. Lough Ree and Storage (Use of storage in Bord na Mona owned, cutaway bogs to enable
excess winter water to be stored for later use in drier summer periods)
F. Lough Derg and Storage (Use of storage in Bord na Mona owned, cutaway bogs (F1 & F2)
to enable excess winter water to be stored for later use in drier summer periods)
G. Impoundment (Abstraction from Lough Ree in high flow periods. Raw water impounded in
dams / valleys in Dublin / Wicklow mountains for use during Shannon low flow periods)
All River Shannon water supply options would involve the construction of pumping facilities to abstract
raw water, and pipelines / treatment plants to bring treated water to consumers in the Dublin Region.
Options A – D rely on existing Shannon lake storage while Options E – G involve supplementary
external raw water storage.
Options A - F have the potential to supply treated water to Local Authorities en route between the
Shannon and Dublin.
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1.8.2
The Plan
Irish Sea Water Supply Option
H. Desalination
The Desalination water supply option is outlined in Figure 1.7. This option would involve the
construction of a Desalination Plant (optimum site identified in North-East Fingal) and pipelines to
transport the desalinated water to the Dublin Region water supply network at Ballycoolen Reservoir.
This option benefits from unlimited raw water supply (Irish Sea) and relative proximity to the demand
centre. These benefits are offset by cost of treatment, particularly energy cost.
Figure 1.7
Desalination Option Schematic
Desalination
Desalination Plant:
Plant:
Phase
Phase 22 capacity:
capacity:
300
300 Mld
Mld
Sea
Sea Water
Water Pumping
Pumping Station:
Station:
Ph
Ph 22 :: 715
715 Mld
Mld
Reverse
Reverse Osmosis
Osmosis Treatment
Treatment Plant:
Plant:
Ph
Ph 22 :: 300
300 Mld
Mld
Potable
Potable Water
Water Pumping
Pumping Station:
Station:
Ph
Ph 22 :: 300
300 Mld
Mld
2
De x 1
si 400
gn m
ca m
pa Ø
ci Pre
ty s
: 4 su
15 re
M M
ld ai
n
Ballycoolen
Ballycoolen Reservoir
Reservoir
24 km
2
De x 1
si 100
gn m
ca m
pa Ø
ci Pr
ty es
: 3 su
00 re
M M
ld ai
n
2
De x 1
si 800
gn m
ca m
pa Ø
ci Pr
ty es
: 7 su
15 re
M M
ld ai
ns
s
(2
km
)
(3
km
)
s
MDW0158SK0045 Desal
1.8.3
I.
Other Water Supply Options
Groundwater
This water supply option examined the potential for the development of groundwater supply sources
in the Fingal and Kildare areas and extension to consideration of full hinterland within an 80km radius
of Dublin (see Appendix C).
J. Liffey Barrow Conjunctive Use
Approx 50% of the Dublin Region’s water supply comes from Poulaphuca Lake on the Upper Liffey
via Ballymore Eustace Water Treatment Plant. The Liffey-Barrow ‘conjunctive use’ option would
involve sustainable abstractions of water from the River Barrow when sufficient quantities of water
may be available (eg during higher flow periods) and combining these abstractions with variable
abstractions from Poulaphuca with a view to increasing the overall supply to Ballymore Eustace
Water Treatment Plant over and above what is sustainably available from Poulaphuca on its own.
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1.8.4
The Plan
General Option Overview
All options considered are not of equal
merit. Some have capacity limitations
(eg Groundwater & Liffey Barrow) and
are unable to meet anticipated supply
requirements. Some options are
preferred over others from an
environmental
sustainability
perspective and there are cost
differences between options which
have to be assessed in conjunction
with option technical & environmental
performance.
1.9
EVALUATION OF OPTIONS
1.9.1
Option Evaluation Methodology
The Option Evaluation methodology which was used for assessing water supply involved two separate
but interrelated processes;
1) Multi Criteria Analysis (Sustainability Assessments)
2) Strategic Environmental Assessment (Public Consultation)
Multi Criteria Analysis (Sustainability Assessments) and Strategic Environmental Assessment (Public
Consultation) are closely linked (see Figure 1.8) – this reflects the overlap in environmental
considerations within the two separate processes.
Figure 1.8
Multi Criteria Analysis & Strategic Environmental Assessment
Draft Plan
Multi-Criteria
Analysis
(Sustainability
Assessments)
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HDA Report
24
Strategic
Environmental
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1.9.2
The Plan
Option Evaluation & Selection Process
Figure 1.9 outlines the overall Option Evaluation & Selection process. The ‘Preliminary Evaluation’
stage includes the initial Feasibility Studies of 3 Options, followed by SEA Phase 1 which resulted in
an expanded range of options and Feasibility Studies of the total options (10 No.) which were
considered.
The ‘Detailed Evaluation’ stage involved Multi Criteria Analyses (Sustainability Assessments) leading
to the development of the Draft Plan which was tabled for Public Consultation under SEA Phase 2 in
conjunction with the Environmental and Habitats Directive Assessment (HDA) Reports.
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Figure 1.9
The Plan
Option Evaluation & Selection Process
Feasibility Study of 3 Options – 2004/5
Preliminary
Evaluation
Strategic Environmental Assessment (SEA) – Phase 1
3 Options – Public Consultation ( June 06 – Oct 06)
Feasibility Study of 10 Options – 2007/8
Multi Criteria Analysis (MCA)
Sustainability Criteria
-
Technical
Environmental
Economic
Socio-economic
Draft Plan
SEA Phase 2
Detailed
Evaluation
Environmental
Report
HDA Report
Public Consultation
Analysis of Feedback
Recommended Option (Multi Criteria Analysis / Public Consultation / Risk)
Preliminary Report – Recommended Option
Multi Criteria Analysis (MCA) – technical / environmental / economic / socio-economic
evaluation of options to assess the potential for compliance with the principles of sustainable
development
Strategic Environmental Assessment (SEA) of options including feedback from SEA
public consultation
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1.10 SELECTION OF RECOMMENDED OPTION
The ranking of options based on MCA & SEA Evaluations was;
1)
2)
3)
4)
Option F2 (Northern Lough Derg & Storage Garryhinch Cutaway Bog)
Option B (Lough Derg Direct)
Option C (Parteen Basin Direct)
Option H (Desalination)
1.10.1 Recommended Option F2
Shannon Option F2 which has emerged as the recommended preferred scheme involves abstraction
form north eastern Lough Derg of up to 410Ml/d of raw water (when Shannon flow conditions permit),
pumping in a twin rising main to large raw water storage at Garryhinch, treatment at Garryhinch and
treated water transmission to Dublin, Mid East and Midlands Regions. The proposed scheme, which is
subject to phasing, would comprise the following at full development;
x
Raw water intake at Lough Derg and pumping station following screening with capacity up to
410Ml/d
x
Twin 1400mm raw water rising main, 62 km long with capacity to 410Ml/d and operating
pressure 15 bar
x
Raw water storage capacity at Garryhinch of 12 million cubic metres to balance seasonal
Shannon flows
x
Water Treatment Plant (at Garryhinch), expandable in modular fashion up to a maximum
design capacity of 356Ml/d
x
Twin 1200mm treated water rising main, 54 km long with capacity of 306Ml/d with associated
treated water pumping station
x
Balancing reservoir of capacity 42Ml and top water level 90-100m OD with transfer pumping
station
x
Feeder mains (twin 1000mm) to existing Saggart (DCC) and Peamount (SDCC) service
reservoirs and augmentation from Peamount to Leixlip WTP to supplement that source.
Option F2 is the lowest cost option which is capable of meeting the Dublin Region’s long term water
supply needs up to 2040 and beyond, whilst complying with all significant environmental constraints.
The incorporation of large scale external raw water storage into the overall water supply scheme
(through use of BNM cutaway bogs), in conjunction with abstraction of raw water from Lough Derg’s
storage (controlled by ESB), ensures that the solution is technically robust and capable of meeting the
long term water supply requirements of the Dublin & Midland Regions, in an environmentally
sustainable and cost effective manner up to and beyond the 2040 planning horizon.
The recommended solution has the potential to benefit local Midland’s communities through the
development of nature parks associated with raw water storage, provision of (indirect) water supplies
to the Royal Canal and provision of water supplies particularly to Offaly, Laois and Westmeath County
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Councils, with up to 50Mld available for this Region. A contingency allowance of 50Mld is also
provided.
A number of environmental / technical & economic advantages of the recommended scheme are
outlined as follows;
Environmental Advantages
x
Operational lake levels in Lough Derg are not affected by water abstractions for Dublin as
ESB hydropower generation activities at Ardnacrusha provide counter balancing effects.
Accordingly, lake levels will not be impacted by the abstractions
x
The proposed raw water storage at Garryhinch creates a Midlands lake which can be filled
with water abstracted during high flow & flooding periods on the Shannon
x
‘Abstraction-related’ increased residence time increases and associated environmental
issues, which represented a major stakeholder concern in Lough Derg, are minimised during
low flow periods as raw water storage at Garryhinch allows abstractions to be reduced or
ceased when Shannon flows are low (the details of the abstraction methodology will be finetuned during EIA with the planned development of Hydrodynamic & Water Quality Modelling
and data inputs from proposed monitoring & measurement equipment)
x
Large scale raw water storage will secure water supplies, while supporting the development
of water based amenities and environmental parks with knock-on tourism benefits for the
Midlands as a secondary benefit. Proposed eco-tourism facilities at the site are being
modelled on similar facilities which were created at Rutland in the UK by Anglian Water
where bird watching, angling and water sports have considerably enhanced the economic
earning potential of the region. The core range of ideas and potential uses for the Garryhinch
raw water storage reservoir are likely to include;
x
o
Non motorised water
canoeing/kayaking
o
Natural Environment: Bird watching, ecology zones and interpretation and angling,
perhaps a lido and beach for peak summer season activity and events
o
Trails: Cycle, walking and jogging
o
Events: sport related (Triathlon, open water swimming) and other (concerts,
education, special interest groups)
o
Landscape Design: high quality parkland surrounding the reservoir and water
features
o
Education: Education centre and officer to accommodate education tours in relation
to water conservation and treatment.
sports:
Dingy
sailing,
windsurfing,
kite
surfing,
The raw water reservoir (at Garryhinch) is proposed to be the first dual purpose reservoir in
Ireland designed from the outset to meet two core functions i) water supply and ii) recreation
& leisure.
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o
It will be designed to offer ease of recreational use and optimal access to the public
o
It will factor in security, and health & safety issues
o
It will be a key element of the tourism offering at a local, regional and national level
o
It will seek to develop links and networks with other similar reservoir destinations
internationally
x
The proposed storage facilitates relocation of substantial infrastructure footprint (e.g.
Treatment Plant) from the sensitive Shannon landscape to the Midlands cutaway bog site
where it can be accommodated without significant visual impact
x
Potential supply of treated water to Westmeath (Mullingar) would indirectly enable the
upgrading of the water supply to the Royal Canal by releasing Lough Owel flows from water
supply to support the canal flows
Technical & Economic Advantages
x
This option has the capacity to fully satisfy the water supply needs of the Dublin, Mid East (&
Midlands) Regions to the planned design horizon (2040) and beyond
x
Large scale raw water storage at Garryhinch provides back-up in the event of unforeseen
circumstances arising (e.g. major pollution incident on the Shannon) increasing the
robustness of the supply to the Region
x
Storage provides a facility to manage peaks in water demand from the Midlands
(Garryhinch) rather than from the Shannon. This involves savings in infrastructure and
operation costs
x
Raw water Midlands storage facilitates reductions in treated water storage needs in Dublin
because of the scale of strategic storage proposed for Garryhinch at relatively low cost
x
Raw water storage facilitates optimum use of renewable power (wind) to pump raw water,
accommodating the intermittent nature of this energy source
x
Availability of secure water supplies with adequate headroom in the Dublin & Midland
Regions will support economic opportunities, for example strategic industry & tourism
development, while minimising risk to existing users at times of peak demand.
1.11 INFRASTRUCTURE – RECOMMENDED OPTION
1.11.1 Key Infrastructure Components
The recommended water supply scheme (Shannon Option F2) to bring treated Shannon water to the
Dublin Region involves;
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x
Abstraction of raw water from northern Lough Derg on the River Shannon and Pumping of
raw water from Lough Derg to Garryhinch cutaway bog, owned by Bord na Mona, located
near Portarlington
x
Large scale storage of raw water within Garryhinch cutaway bog and treatment facilities at
the site to produce potable water
x
Delivery of treated water to a termination reservoir in the Dublin Region and onward delivery
of treated water from the termination reservoir to Saggart and Peamount Service Reservoirs
Figure 1.10 below summarises the key elements, sizing and capacities of the proposed scheme in
schematic form.
Figure 1.10
Option F2 Northern Lough Derg & External Storage at Garryhinch
Lough
Ree
Termination Point
Reservoir
Peamount
Reservoir
River
Shannon
Lough
Derg
Parteen
Basin
R
& aw
Pu W
m ate
pi r
ng Ab
St str
at ac
io ti
n on
Storage
(Raw Water )
62
R k
Pr aw m t
es W wi
su ate n 1
re r – 40
:1
0
5 -2 124 ĭ p
0b km ip
ar to elin
ta e
l
Garryhinch Bog
(Bord na Mona)
Saggart
Reservoir
54
D km
W
15
Pr rink tw
& ate
In km
es in in
Tr r T
su g
Dr teg tw
12
ea re
W
i
r
Pr nk rat in
e: a 00
te at
es in io 10
d m
10 ter ĭ
W en
su g n – 00
-2 – pi
at t
0b 10 pe
re Wa 30 ĭ
er P
: 5 te k pi
ar 6k lin
PS lan
m pe
s
m e
-1 r
t
0
to lin
to
ba
ta
ta
l e
rs
l
River Shannon
MDW0158SK53D08
1.12 COST OF RECOMMENDED OPTION
Net Present Values (NPV) of Capital (Capex) and Operating (Opex) costs have been prepared for
recommended Shannon Option F2 based on the scope of infrastructure requirements outlined above.
Costs are discounted to 2010 base year.
NPVs (2010) have been prepared for three annual discount rates (3%, 5% and 7%). Cost estimates
for infrastructure construction and operation of the water supply scheme are based on 2010 plant,
material and labour costs.
The Whole Life Cost of the recommended water supply scheme for a 25 year (2020 – 2045)
operational period has been calculated by adding the discounted capital cost, capital renewal cost
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and operating cost over the 25 year period and subtracting the discounted residual value of the
scheme at the end of the period (2045). A ‘cost of water delivered’ was calculated by dividing the
Whole Life Cost by the estimated amount of water to be produced / delivered by the scheme over a
25 year operational lifetime.
Table 1.6 summarises the 2008 Net Present Values of Capex, Opex and Whole Life Costs for the
recommended scheme over the 2020 – 2045 period, using three typical annual discount rates (3%,
5% and 7%).
Table 1.6
Capex / Opex / Whole Life Cost / Water Delivery Cost (2020 – 2045)
DISCOUNT RATE (per annum)
3%
5%
7%
NPV CAPEX (€000’s)
603,075
545,816
501,765
Investment
376,491
356,156
338,749
One off items (Contractor Prelims / Wayleaves /
Project Management etc)
94,787
90,056
89,948
Capital Renewal
131,796
99,604
77,068
NPV RESIDUAL VALUE (€000’s)
220,016
125,963
72,879
NPV OPEX (€000’s)
165,186
121,773
92,100
NPV Capex + Opex - Residual Value (€000’s)
548,244
541,626
520,986
Volume of Water Delivered Ml
1,329,841
1,329,841
1,329,841
(NPV Capex + Opex - Residual Value) / Volume
0.41 €/m3
0.41 €/m3
0.39 €/m3
NPV Opex / Volume
0.12 €/m3
0.09 €/m3
0.07 €/m3
1.13 PROGRAMME – IMPLEMENTATION OF RECOMMENDED OPTION
A typical programme for project implementation (by 2020) has been developed based on three
distinct but interrelated project development phases as follows
x
Planning Phase 2010 – 2014
–
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x
x
The Plan
–
Preparation & Submission of Planning Application to An Bord Pleanála
under the Strategic Infrastructure Act (SIA)
–
Processing of Planning Application by An Bord Pleanála
Procurement Phase (2014 – 2016)
–
Compliance with EU Procurement requirements & Assessment of
Procurement Options, development of Contract Documents and
Procurement of Tenders
–
Assessment of Tenders & Appointment of Service Providers / Contractors /
Operators etc
Construction & Commissioning Phase (2017 – 2020)
–
Construction involving Multiple Contracts operating in parallel in ‘Green
Field’ site conditions (programme assumes full Planning Consent & Site
Availability at construction commencement)
–
Commissioning
The achievement of the above target delivery dates are based on many assumptions regarding 3rd
party performance (e.g. An Bord Pleanála) and approval requirements (e.g. DEHLG) at each stage
including arrangements for financing of the project.
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2 NEED FOR PROJECT
2.1
INTRODUCTION
Demand for treated water in the Dublin Region currently exceeds the sustainable production capability
of the existing water treatment plants at Ballymore Eustace, Leixlip, Roundwood and Ballyboden. As a
consequence, these plants are being operated in an unsustainable manner in order to meet day to day
demand requirements. This ‘knife – edge’ operational regime and lack of ‘headroom’ availability in the
Region presents an ever increasing risk to continuous supply availability, particularly from supply
network failure or short-term demand peaks. There is little scope for critical infrastructure components
to be taken out of service and upgraded as appropriate, which is not a sustainable operational
situation. Availability of adequate headroom is essential for servicing the needs of future industrial and
other employment led demand in the Region as the economy recovers, and also for meeting peak
demand and normal good practice operations.
Whilst operating with little or no headroom, demand growth over the past decade in the Dublin Region
has largely been met by water savings from leakage management, water conservation initiatives,
incremental expansion of Ballymore Eustace water treatment plant and operation of all treatment
plants beyond their sustainable production capacities. Supply has stayed marginally ahead of average
demand and Local Authorities have generally succeeded in maintaining supply by optimising
production and strategic storage.
Short term future demand growth will continue to rely on
further water savings from reduced levels of personal
consumption (domestic metering & charging), sustained
leakage
management
including
planned
network
rehabilitation and additional water availability resulting from
the expansion of Ballymore Eustace & Leixlip water treatment
plants in conjunction with new supplies from the Barrow. The
scale of increased water availability from these initiatives,
however, will at best maintain the status quo taking account
of the increasing short term water demand growth in the
Region. It will not address the lack of strategic ‘headroom’
capacity.
A Department of Environment Heritage and Local Government (DEHLG) Strategic Study in 1996 first
identified that the Dublin Region could potentially require water supplies from a new source within 20
years in order to avoid serious disruption to supply continuity and the associated threat to the socioeconomic development of the Mid East & Dublin Regions. A DEHLG review of the 1996 study in 2000,
confirmed the 1996 analysis.
The analyses of projected demand growth scenarios
contained in this report builds on the findings of the 1996
and 2000 studies and include updated assessments of
projected population growth, economic growth and
anticipated water savings from leakage management / water
conservation measures including anticipated savings arising
from the introduction of domestic metering & charging. The
supply / demand assessments conclude that large-scale
water supplies from a new supply source are essential to
ensure guaranteed supply availability into the future to
satisfy population and economic growth in the Region. The
demand / supply analysis concluded that supplies from a new source are required by 2022 (latest) and
could be required earlier if reductions in personal consumption and water savings from leakage
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management are not achieved as planned. The analysis identified that a total requirement of 300Mld
(million litres per day) would be required to ensure sufficient capacity and headroom to meet the
Region’s average and peak demand needs up to 2040 and beyond.
Prudent planning would suggest that such an outcome is prepared for now, on account of the long
lead times for delivery of major capital investment projects required to meet these future demands.
Indeed, given the complex planning and procurement processes involved in a project of this type and
scale, a 10 year timeframe is challenging to bring a new major water source into service.
Demand projections are summarised in Table 2.1 and sustainable yields of existing Dublin Region
sources are summarised in Table 2.2. Detailed analysis of supply and demand including international
‘best practice’ comparisons are contained in Appendix AB.
2.2
IRISH GOVERNMENT ECONOMIC POLICY
High level Irish Government policy in relation to economic growth is set out in the National Spatial
Strategy (NSS) and National Development Plan (NDP). Both of these policy documents recognise
that national economic-growth objectives will continue to require managed development of the
Greater Dublin Area (GDA) / Dublin Region to its full potential since the Region generates over 50%
of economic growth in the country and any constraints in development of the Greater Dublin Area
would have a major adverse impact on socio-economic advancement nationally. Economic growth
objectives are provided for in the (Dublin & Mid East) Regional Planning Guidelines (2010 – 2022),
supported by development plans in each Local Authority area within the Region.
From a broader perspective, the recent World Economic Forum Water Initiative Report (published
Jan 2009) identified clearly that countries in temperate zones (like Ireland) were well positioned to
avoid the more severe impacts of the impending global water crisis. Water security, economic
development and GDP are closely interlinked and as a consequence business and capital will
increasingly be attracted to economies with secure supplies of quality water and sound water
management practices. The ability to attract Foreign Direct Investment (FDI) is closely linked to the
availability of secure high quality water supplies as international businesses are unlikely to be
attracted to areas of poor water quality or where there are risks to availability. The potential attraction
of Ireland is particularly true for ‘wet’ multi national industries, hence the success of Cork in attracting
the pharmaceutical sector and the Dublin Region in securing investment from Intel / Wyeth to quote
but just a few examples.
However, secure sustainable water management policies require full compliance with the EU Water
Framework Directive (WFD). The WFD requires that ‘good’ water quality is achieved and maintained
for all surface and ground water bodies from 2015. This in turn requires that both existing and future
water abstractions are consistent with the WFD objectives, including taking due account of the land
use objectives and climate change. Ireland generally and the Dublin region specifically, has the
opportunity to underpin its socio-economic infrastructure, by providing for secure sustainable water
supplies consistent with those objectives.
2.3
WATER SUPPLY – OBJECTIVES
To support national strategies for economic growth in the Dublin & Mid East Regions, it is essential
that longterm secure supplies of high-quality water are available throughout the Regions. The
Regional Water Authorities' objectives, incorporated into Regional Water Services Strategic Plans,
aim to ensure the availability of secure sustainable water supplies, which provide:
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x
guaranteed supplies of water throughout the Region to meet daily needs, including day-time
and seasonal peaks
x
flexibility to increase water supply to meet development needs as these increase over time
x
a margin between supply and demand to ensure that supply is secure in the event of local
system failures (treatment-plant breakdown, trunk main bursts, pollution, etc), periodic
demand peaks and good practice service maintenance of the water supply infrastructure
This approach is in line with best international practice and requires:
2.4
x
reliable sources and treatment systems
x
adequate pipeline and storage capacities
x
robust, well-managed distribution systems
x
flexibility between sources to cope with contingencies
x
responsible management and use of water, including minimisation of water use through
volumetric metering & associated charging regimes which incentivise conservation
x
control of water leakage by customers
x
responsible use of water for non-essential purposes
DEMAND PROJECTIONS
The assessments of demand growth in the Dublin Region for the 2010 – 2022 – 2031 – 2040 period,
have built on the findings of the DEHLG 1996 and 2000 studies and include updated assessments of
projected population growth (as per the 2010 - 2022 Regional Planning Guidelines & National Spatial
Strategy 2030), economic growth projection ranges and anticipated water savings from leakage
management / demand management / water conservation measures. Two principal demand scenarios
have emerged from the analyses – Maximum Planning Scenario & Minimum Planning Scenario.
The ‘Maximum Planning Scenario’, was prepared in 2007 for Phase 2 of the Strategic Environmental
Assessment process.The 2007 demand forecasts were based on an approach involving strong
emphasis on network rehabilitation and active leakage control programmes with demand management
strategies limited to customer awareness programmes, building bye-laws, promotion of water efficient
appliances and 100% metering of the non-domestic sector. This scenario involved a (relatively) lower
emphasis on extensive domestic demand management initiatives in the absence of policies requiring
domestic metering & charging. The Maximum Planning Scenario main assumptions are summarised in
Section 2.4.1 .
2.4.1
Maximum Planning Scenario
-
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-
Reductions in personal usage (1% - 2%) resulting from customer awareness
programmes, building bye-laws and greater use of water efficient appliances
-
Reductions in customer leakage (1% - 2%) resulting from customer
awareness programmes
-
Reductions in Distribution Network Leakage (Network Rehabilitation) to 20%
(2030 – 2040)
-
Medium to High Economic Growth (all zoned lands developed by 2030)
The Minimum Planning Scenario main assumptions are summarised in Section 2.4.2.
2.4.2
Minimum Planning Scenario
The ‘Minimum Planning Scenario’ demand projections are based on the ‘Minimum Achievable’
scenario in the Demand Review (Appendix AB) which was carried out following proposals signalled by
Government in draft Budget 2010 with respect to metering and volumetric charging for domestic water
supplies. The Minimum Achievable / Minimum Planning Scenario assumes that best practice water
conservation measures are being implemented in the Dublin & Mid East Regions in advance of the
introduction of any supplies from a new source. Domestic demand growth forecasts assume that
personal consumption is reduced by up to 15% as a result of the domestic metering policy changes.
Customer leakage is reduced by up to 70%. Distribution system leakage is reduced from 29% to 20%
through active leakage management and network rehabilitation. Forecast non domestic demand
growth rates are reduced by up to 30% to reflect the current economic slowdown (2008 – 2010).
-
Full introduction of Domestic Metering & Charging by 2020 – 2022
-
Reductions in personal usage (up to 20% resulting from metering & charging)
-
Reductions in customer leakage (up to 70% resulting from metering &
charging)
-
Reductions in Distribution Network Leakage (Network Rehabilitation) to 20%
by 2040
-
Low to Medium Economic Growth (all zoned lands developed by 2040)
The Minimum Planning Scenario is regarded as the ‘best practical environmental & economic
scenario’ and is recommended in this Plan as the scenario on which planning for the development of a
new water supply is based. It assumes that water savings are optimised through best practice
management of leakage and personal consumption. This approach was advocated in much of the
SEA public consultation stakeholder feedback which is fully accounted for in this scenario. Detailed
demand projections for the Dublin Region, based on the Minimum Planning Scenario, are contained in
Appendix A.
2.4.3
Extent & Timing of Water Supply Needs
The extent of the Dublin Region’s future water supply needs from a new source and the timing of the
initial supply requirements are based on forecasts of water demand growth across all consumer
sectors (domestic / industrial / commercial) combined with anticipated performance in leakage
management / water conservation and economic growth. Demand projections are summarised in
Table 2.1.
The extent and timing of the future requirements are also dependent on the sustainable yield of the
existing supply sources in the Region (See Table 2.2 & Table 2.3).
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The Plan
Demand Projections Summary
Estimates of future demand growth for the Dublin Region based on the Minimum Planning Scenario
have been calculated as follows;
Domestic Demand
Domestic demand is a product of population and personal consumption (per capita consumption).
x Domestic consumption is based on population forecasts contained in GDA* Regional
Planning Guidelines (2010 – 2022) and Central Statistics Office (CSO) / Economic & Social
Research Institute (ESRI) long range GDA population forecasts for the 2022 – 2031 period
contained in the National Spatial Strategy. Population forecasts for 2040 are extrapolated
from previous years
* GDA = Greater Dublin Area = Dublin & Mid East Regions
x Forecast PCC levels, assume the implementation of full domestic metering by 2020/22 (in
line with Government commitment to metering of domestic water supplies ) and also assume
volumetric charging of customers using tariffs which are geared towards incentivising water
conservation in domestic premises. Current PCC levels of 147l/hd/d (2010) are forecast to
reduce to 135l/hd/d (2022) and 130l/hd/d (2031). These projected PCC levels are similar to
Walker Report recommendations in the UK which have been targeted for 2030 (see
Appendices AA & AB). Given the Dublin Region’s starting position they represent difficult
targets but, nevertheless, targets which could realistically be achieved with the correct
strategies & policies in place. They would also move Ireland / Dublin a long way in the
direction of ‘best international practice’ for this component of demand on a ‘like for like’
comparison basis.
Non Domestic Demand
x Between 2010 and 2040 projected water consumption levels are based on full development
of lands currently zoned for industrial & commercial usage in the Local Authorities which
comprise the Dublin Region (Water Supply Area)
Leakage
x Leakage from Distribution Systems, currently estimated at 29% (2009), is projected to
reduce to 20% by 2040. Reductions will be brought about by active leakage management
and network rehabilitation. Leakage levels of 20% are internationally regarded as ‘the likely
economic level of leakage’ for this type of network, largely consisting of old cast iron and
ductile iron mains. Best international practice for this type of network is discussed in
Appendix AB. The proposed leakage targets make realistic allowances for the timeframe for
replacement of older mains and the leakage influences which must be pro-actively managed
as a continuous process to achieve this target
x Customer side leakage is currently estimated at 65 litres/property/day across the region. This
reflects the age and complexity of services to properties, unknown connections, and
unattended leaks. The introduction of domestic metering will highlight leakage on metered
supplies which will encourage households to identify, locate and repair such leaks, especially
where the cost of water lost is significant compared to the repair cost. Current customer side
leakage levels of 65l/prop/d (2010) are forecast to reduce to 35l/prop/d (2022) and 25l/prop/d
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(2031) – these targets are in line with best international practice when considered on a ‘like
for like’ comparison basis
Table 2.1 (below) summarises water demand growth scenarios for the Dublin Region based on the
above Minimum Planning Scenario.
Table 2.1
Average / Peak Demand (2010 – 2040) – Dublin Region (Water Supply Area)
Description
Unit
2010
2022
2031
2040
Population
No
1,490,000
1,908,455
2,293,235
2,694,790
Households
No
596,000
763,000
917,000
1,078,000
hd/house
2.50
2.50
2.50
2.50
l/hd/day
147
135
130
130
Domestic Demand
Projection
Mld
218
258
298
350
Non Domestic Demand
Projection
Mld
127
184
227
270
Customer Side Losses
Mld
38
26.70
22.90
26.90
Distribution Losses
Mld
161
160
160
160
Operational Usage
Mld
2
2
2
2
*Barrow Supply
(Kildare)
Mld
-10
-10
-10
Total Average
Mld
545
621**
700
800
Total Peak***
Mld
594
678
767
879
Occupancy Rate
Per Capita
Consumption
* Kildare estimated to reduce its requirements from the Dublin Region (10Mld – 20Mld) from 2013
when the Barrow scheme is anticipated to come on stream. The more conservative 10Mld has been
used for these demand projections
** Maximum sustainable production of existing Dublin Region sources is 627Mld
*** Peaks in demand – 12.5% of (Distribution Input – Leakage)NB.
NB: The average demand in the Dublin Region in 1996 was 460Mld servicing a population of
1,180,000
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The Plan
DEMAND REQUIREMENTS – MIDLANDS
In addition to supplying water to the Dublin & Mid East Regions the proposed water supply scheme
from the Shannon may also be required to supply water to Laois, Offaly and Westmeath Co Councils.
An allowance of 50Mld has been provided for supplies to population in these counties – up to 50Mld
contingency allowance has also been provided.
2.6
PRODUCTION CAPABILITY OF EXISTING SOURCES
Table 2.2 outlines the current and projected production capabilities of the existing Dublin Region
public water supply sources and also the anticipated production of Kildare Wellfields and the River
Barrow. The projected longterm production represents the maximum sustainable production limits of
the respective sources.
The maximum sustainable availability of water from the Liffey River is 318Mld (BME) and 215Mld
(Leixlip). These maximum sustainable production capacities are anticipated to be fully developed by
2014. Between now and 2014 there is some limited potential in the BME and Leixlip Water Treatment
Plants to produce additional treated water quantities (see red numbers Table 2.2). This additional
water production is not operationally sustainable but is being currently utilised to meet ongoing
demand growth requirements. New supplies from the Barrow from 2013 onwards will reduce Kildare’s
dependence on Dublin Region sources (by 10Mld – 20Mld).The sustainable production from all
existing Dublin Region sources when fully developed is estimated at 627Mld – available from 2014
onwards (assuming that Leixlip expansion is complete by 2014) – see Table 2.2.
Table 2.2
Treated Water Production from Existing Sources
Source
Units
BME (Sustainable)
2009
2010
2011
2012
2013
2014
2015
274
318
318
318
318
318
318
148
148
148
148
148
215
215
168
168
168
168
168
Mld
294
Production 2009 / 2010*
Leixlip (Sustainable)
Mld
Production 2009 – 2012*
Roundwood
Mld
75
75
75
75
75
75
75
Ballyboden
Mld
16
16
16
16
16
16
16
Bog of the Ring
Mld
3
3
3
3
3
3
3
516
560
560
560
560
627
627
556
580
580
580
580
TOTAL Sustainable
Mld
Total Production*
Kildare
-
Wellfields
Mld
3
3
8
8
8
8
8
-
Barrow
Mld
-
-
-
-
30
30
30
Mld
3
3
8
8
38
38
38
Kildare Total
*Unsustainable production: plants are operating within their design capabilities but cannot operate
indefinitely at these levels as it limits good maintenance practice.
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The Plan
DEMAND/SUPPLY BALANCE
Table 2.3 summarises the Demand / Supply Balance for the 2010-2040 period. Demand projections
are based on the Minimum Planning Scenario which assume full implementation of domestic metering
by 2020 – 2022 coupled with significant leakage reductions arising from ongoing network rehabilitation
Table 2.3
Demand / Supply Balance (Mld)
Average
Dublin
Region
Demand
Non
Sustainable
Production
Existing
Sources
Year
Sustainable
Production
Existing
Sources
Peak
Dublin
Region
Demand
2010
560
546
580
594
2011
560
553
580
602
2012
560
561
580
611
2013
560
568
580
619
2014
627
566
N/A
616
2015
627
573
N/A
624
2016
627
580
N/A
632
Critical
2020
627
608
N/A
664
Period
2022
627
621
N/A
678
2031
627
742
N/A
768
2040
627
800
N/A
879
From 2010 to 2012 the completion of Ballymore Eustace (318Mld) enables average demand to be met
from sustainable production of existing sources.
Between 2012 and 2014 meeting average demand requires additional unsustainable production at
Leixlip of approx 20Mld.
From 2015 onwards (assuming that Leixlip expansion is complete by 2014) the sustainable production
capacity (627Mld) is also the maximum production capacity as abstractions from all Dublin sources will
have reached their licensed sustainable limits. Anticipated peak demand from 2015 / 2016 onwards
begins to exceed the maximum sustainable production capability (outlined in amber).
The critical period, outlined in red, Table 2.3 above, is reached when average daily demand begins to
exceed the maximum sustainable production capacity of existing sources. This situation is projected to
occur approx 2020 / 2022 based on demand projections which assume full implementation of domestic
metering coupled with leakage reductions arising from ongoing network rehabilitation. Supplies from a
new source will be required at that stage if current levels of service are to be maintained.
In addition to the above, localised supply shortages are possible in certain areas before 2020, since
infrastructure restrictions in the network prevent the outputs from the various water production facilities
being used in all distribution areas.
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The Plan
CLIMATE CHANGE
Climate change analyses for the East of Ireland project rainfall increases in Winter (+10% to +20% for
2010 – 2039) and reductions in Summer (-20% to -40% for 2010 – 2039). Projected increases /
reductions in Winter / Summer rainfall for Ireland East have been advised by climate experts at NUI
Maynooth (ICARUS). Raw water storage facilities at Poulaphuca and Roundwood have some limited
potential for offsetting Winter rainfall increases against Summer rainfall reductions but the net effect of
climate change in the East of Ireland will result in a long term gradual reduction in the sustainable yield
of existing Dublin Region sources.
Ireland generally, and the East in particular, have had a series of wet summers in recent years and
consequently, raw water shortages in the Region, as a result of drought conditions, have not arisen.
However, there is little doubt that if a 1975 / 76 type drought weather pattern re-emerged in the East
before supplies from a new source become available, significant water shortages, particularly in the
Liffey, could occur, leading to a return of water rationing and restrictions. A new supply source is
necessary to ensure that this situation does not materialise.
In almost all years, Poulaphuca reservoir fills to its maximum operating level (consistent with
managing flood risk) during the winter / spring season. This sustains summer river flows and
abstraction levels. Climate change could adversely impact on water availability for Dublin from the
Liffey in a number of ways:
2.9
x
Increased winter rainfall could lead to lower lake operating levels to manage flooding risk,
leaving less water in storage
x
Dryer summer weather could increase losses (evapotranspiration) depleting resources faster
through the season
x
Dryer summers would be likely to place upward pressure on water demands
TIMING OF NEW SUPPLY REQUIREMENTS
As outlined previously in Section 2.4, two Planning Scenarios emerged from the demand growth
analyses (Minimum Planning Scenario & Maximum Planning Scenario).
The ‘Minimum Planning Scenario’ is the recommended Planning Scenario as it entails an overall
integrated water resource management solution for the Dublin Region.
In the Minimum Planning demand growth scenario, supplies from a new source are likely to be
required by (latest) 2022 when average day demand equals the sustainable production capacity of
existing sources (627Mld). The timing of new supply requirements for this scenario is illustrated (solid
green line) in Figure 2.1. If planned leakage targets or savings from reduced personal consumption
experience slippage then the demand projections represented by the ‘solid green line’ will move
backwards towards the ‘dotted green line’ potentially necessitating an earlier need for water supplies
from a new source.
In the Maximum demand growth scenario (Strategic Environmental Assessment Phase 2 Planning
Scenario) involving higher economic growth rates and reduced savings from demand management,
water conservation & leakage, supplies from a new source were identified as potentially being required
as early as 2016 (coloured red) in Figure 2.1.
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In order to plan prudently for slippages in achievement of water savings from leakage reductions and
water conservation it is recommended that supplies from a new source are made available from 2020
onwards. Assuming the planning process commences in 2010, this date also represents the most
likely ‘earliest delivery date’ for the project (Planning Process 4 years / Procurement 2 years /
Construction 4 years).
The Minimum & Maximum Planning demand growth scenarios, potential slippages in ‘supply-demand’
targets and earliest project delivery dates are all illustrated schematically in Figure 2.1.
Figure 2.1
Minimum & Maximum Average Water Demand Growth Scenarios
850
Maximum Planning Scenario
(SEA Phase 2)
800
750
Minimum
Planning Scenario
Earliest Delivery Date
700
50Mld Headroom
650
Mld
Unsustainable
Production
Sustainable Production
600
550
Barrow Supplies on stream
500
450
400
2006
2008
2010
2012
2014
2016
2018
2020
2022
2024
2026
2028
2030
2032
2034
2036
2038
2040
Year
Minimum Planning Scenario
2.9.1
Maximum Planning Scenario (SEA Phase 2)
Headroom
Peak Demand & Headroom Allowances
Demand growth projections in Figure 2.1 are based on ‘Average Demand’. Management of water
demand also requires that sufficient production & storage capacity is available to meet peak demands
at certain times of the year and that sufficient excess capacity (headroom) is also available to cater for
infrastructure failure / plant outages / pollution incidents (eg cyrptospiridium) etc.
The ‘Demand Review’ contained in Appendix AB considered four demand growth scenarios;
x Do Nothing
x Maintain Current (Equivalent to SEA Phase 2 - ‘Maximum Planning Scenario’)
x Minimum Achievable (Equivalent to ‘Minimum Planning Scenario’)
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x ‘Theoretical Minimum’ scenario. This scenario effectively identified each component
of demand (domestic / non domestic / leakage / headroom etc) and ‘cherry-picked’
best practice for each demand component across a range of international water
companies. These best practice projections were then applied to the Dublin Region
growth projections.
Figure 2.2 illustrates the four scenarios for peak demand including provision for headroom based on
international best practice. The graph identifies that even for the ‘Theoretical Minimum’ scenario,
supplies from a new source are still likely to be required in the early 2020’s in order to manage peaks
and have adequate headroom in place.
Figure 2.2
Peak Demand Growth Scenarios (incl Headroom provision)
Peak Water Demand Scenarios
1400
1250
1200
1053
1000
942
800
Mld
742
627
600
400
200
0
2010
2012
2014
2016
2018
2020
2022
2024
2026
2028
2030
2032
2034
2036
2038
2040
Year
Theoretical Minimum
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2.10 EXTENT OF NEW SUPPLY REQUIREMENTS
Dublin Region demand projections have been estimated (Table 2.4 & Table 2.5) for the Minimum &
Maximum demand growth scenarios as follows;
c) The Minimum Planning Scenario – 800Mld average demand reached at 2040
Table 2.4
Minimum Planning Scenario
Dublin Region
(Water Supply
Area)
1996
2008
2010
2016
2022
2031
2040
Average Total
Demand (MId)
460
540
545
580
621
700
800
Max. Production
of Dublin Region
Sources (MId)
470
560
580
627
627
627
627
d) Maximum Demand Growth (SEA Ph 2 Scenario) – 800Mld average demand reached at 2031
Table 2.5
Maximum Planning Scenario (SEA Phase 2)
Dublin Region
(Water Supply
Area)
1996
2008
2010
2016
2022
2031
2040
Average Total
Demand (MId)
460
540
545
627
670
800
N/A
Max. Production
of Dublin Region
Sources (MId)
470
560
580
627
627
627
N/A
Maximum Sustainable Production (2014 onwards) of existing Dublin Region sources is 627Mld.
Supply requirements from a new source have been calculated as shown in Table 2.6.
Table 2.6
New Source Supply Requirements
Average Supply Requirements (at 2031 / 2040) = 800 Mld – 627 Mld
=
173 Mld
Additional Peak Requirements (at 2031 / 2040)
=
80 Mld
Supply Allowance for Midlands Local Authorities
=
50 Mld
Headroom (Contingency) Allowance
=
50 Mld
Supply (new source) Total
=
353 Mld
(say 350Mld)
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2.11 PHASING
The total treated water design capacity of 350 Mld (for the Dublin Region & Midlands) can be
implemented over a number of phases to provide flexibility in catering for gradually increasing demand
growth.
Figure 2.3 below illustrates a two-phased approach - 250 Mld in Phase 1 and 100 Mld in Phase 2 approximately 15 years apart.
Figure 2.3 also illustrates;
x average demand growth Dublin Region
x average demand growth Midlands (Offaly, Westmeath, Laois)
x peak demand (12.5%) growth (Dublin Region & Midlands)
x contingency allowance (new industry / new areas / climate change etc)
x headroom availability (during each new supply phase)
x sustainable production capacity of existing Dublin Region sources.
Figure 2.3
New Source Supply Phases
1000
950
New Source Phase 2
100Mld
900
850
New Source Phase 1
250Mld
Ml/d
800
750
700
650
600
550
Leixlip Final
Extension
500
450
2012
2014
2016
2018
2020
2022
2024
2026
2028
2030
2032
2034
2036
2038
2040
2042
2044
Year
Ave DR
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2.12 NEW WATER SUPPLY SCHEME – PERFORMANCE CRITERIA
Potential new sources of water supply for the Dublin Region (see Chapter 5) were assessed for their
capability to yield 350Mld (as per Figure 2.3) in a technically feasible and environmentally sustainable
manner. The outline designs and costings of water treatment, pumping and delivery infrastructure, for
the various water supply options, were based on meeting the phased production requirements for
treated water over the 2020 – 2040 planning period.
2.13 WATER PRODUCTION SOURCES 2009 – 2040
Figure 2.4 outlines;
1) Average Demand 2009 & 2040
2) Production from Dublin Region Sources 2009 (including Liffey contribution at 83% of total)
3) Projected production from Dublin Region Sources & New (Shannon) Source 2040
Figure 2.4 illustrates that the contribution from the Shannon at 2040 represents just over 20% of total
average supply requirements with the Liffey continuing as the prime source for Dublin contributing in
excess of 65%.
Figure 2.4
Water Production Sources 2009 – 2040
Average Dublin Region Demand
2040 – 800 Ml/day
Average Dublin Region Demand
2009 – 540 Ml/day
16 3
BME
75
172
Leixlip
3
318
16
Roundwood
278
Ballyboden
75
168
215
Bog of the Ring
New Source
River Liffey
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3 WATER CONSERVATION
3.1
INTRODUCTION
While the Dublin (& Mid East) Regions are fortunate in having a number of diverse water sources for
drinking water purposes, this water must be treated at considerable cost and transported through
approx 8,000 km of pipeline network before reaching the end users. The licensed, sustainable
production of water from existing Dublin Region water sources (including planned expansion at BME &
Leixlip) will not be sufficient to meet increased water demand as the Dublin & Mid East Region
population continues to grow. Therefore, it is essential that existing water supplies are conserved and
not wasted through either leaking watermains or excessive consumption.
In achieving economic growth which is sustainable, it is essential that the natural resources and
environmental conditions that are fundamental to the well being of future generations are not
exhausted (EPA, 2008). The EPA (2008) identified water as a resource that is being exploited in an
unsustainable manner. It suggests that individual behaviours must change if a more sustainable style
of living is to be achieved and that there is considerable scope for improvement in relation to the
conservation of water. Therefore the proposed introduction of domestic metering and volumetric
charging combined with awareness campaigns which promote water saving devices are key strategies
for ensuring long-term conservation of water.
The EU Report (SEC (2007) 993) addressing the challenge of water scarcity and droughts in the
European Union’ suggests that the approach which has been used to promote sustainable energy
could be used in a similar fashion to conserve water.
3.2
HISTORY OF WATER CONSERVATION
Water conservation can be achieved in many ways – key areas are as follows:
1.
2.
3.
4.
Repairing leaks both in public and private mains
Rehabilitation of old sections of water pipes
Managing water pressure
Reduction of consumption and customer leakage by metering & charging in the non domestic
sector
5. Reduction of consumption and customer leakage by metering & charging in the domestic sector
6. Education.
Conservation measures (1 – 4 above) have been underway in the Dublin Region for the past 10 – 15
years. Proposed changes to Government policy (2010) now favour water metering and charging for
the domestic sector.
The history of various conservation measures, in place in the Dublin & Mid East Regions over the past
decade and longer, are summarised in the following sections.
3.2.1
Dublin Region Water Conservation Project (DRWCP 1998 / 99)
The Dublin Region Water Conservation Project was led by Dublin City Council and in conjunction with
Wicklow, Dun Laoghaire/Rathdown, South Dublin, Fingal and Kildare County Councils put in place a
network of water meters and telemetry for tracking the distribution of water throughout the Dublin
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Region. The project which cost in the region of €47 million reduced leakage from 42.5% to 29%. A
pressure management system was also set up under the DRWCP to reduce excessive mains
pressure and thereby reduce water wastage losses.
3.2.2
Dublin Region Watermains Rehabilitation Project (2007 – 2012)
This is essentially the second phase of the DRWCP and is currently underway. Many of the DRWSA
Watermains are over 100 years old and have come to the end of their useful life. The purpose of the
Dublin Region Watermains Rehabilitation Project is to conserve water in the Greater Dublin Region by
the rehabilitation of those areas of the network that will yield the greatest water savings in the most
cost effective manner. Leakage has dropped from 40% (1990’s) to 29%(2009). Ongoing investments
in network rehabilitation will be required to reduce leakage levels to 20%. This level of leakage has
been assessed as the ‘economic level of leakage’ for this type of network.
3.2.3
Water Conservation for Schools: Mr. Drippy Campaign
Fingal County Council’s ‘Mr. Drippy’ Water Conservation Campaign for Schools was launched in
March 2007.
The campaign ran in conjunction with 6 other local authorities and was based around a
character who explains, in a fun and simple way, the story of drinking water - where it
comes from and ultimately where it ends up. Mr. Drippy also provided simple tips on how to
reduce the amount of water we use every day.
3.2.4
Tap Tips Campaign
The Tap Tips campaign was set up by the Dublin Region local
authorities to reduce consumption by domestic and
commercial users. It has a dedicated website www.taptips.ie
which gives tips to save water in the house and in the garden
as well as having games and pages for kids to play on and
learn about water conservation.
3.2.5
Water Bye-Laws
Currently Dublin City Council, South Dublin County Council and Fingal County Council all have Water
Bye-laws in place to help prevent the misuse of water and implement various water conservation
measures. The bye-laws are:
x
Dublin City Council Bye-laws for the Management of Water Services and the Conservation of
Drinking Water, 2003
x
Bye-Laws for Preventing the Waste, Undue Consumption, Misuse or Contamination of
Drinking Water Supplied by Fingal County Council, 2004
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x
The Plan
South Dublin County Council Bye-laws for the Management of Water Services and the
Conservation of Drinking Water, 2004.
These bye-laws specify the water conservation requirements in the respective administrative areas. A
few examples of these include:
x
All WC facilities to have a maximum flush of 6 litres;
x
All newly installed WCs or replacement WC shall have a maximum flush of 6 litres;
x
Hosepipe ban during periods of drought as defined by the council;
x
Plumbing systems should be fitted to achieve water conservation objectives;
x
Washing Machines, dishwashers and other appliances shall be plumbed in a manner which
achieves the objective of conserving water
3.3
WATER CONSERVATION SAVING POTENTIAL
The above mentioned water conservation initiatives combined with the implementation of domestic
metering and charging have the potential to save significant amounts of water. These savings have
been incorporated into demand projections (see Section 2 and Appendix A). Summaries of the
potential savings from these measures and future measures are outlined in Sections 3.3.1and 3.3.2.
3.3.1
Measures in Place (2010)
3.3.1.1
Proactive Leakage Management & Network Rehabilitation
As described previously in the DRWCP and the Watermains Rehabilitation Project the projected water
saving targets & timescale of these projects are as follows:
-
Leakage of 29% (2009) is projected to reduce to 20% (2030 - 2040)
-
Savings of 50Mld – 80Mld over a scenario where leakage would remain at 29%
-
Savings have been factored into demand projections
There comes a point where reducing leakage below a certain level (approx 20%) is not economically
viable for networks of this nature – this is known as the “economic level of leakage” below which
increasing levels of expenditures are required for ever decreasing leakage reductions (see Appendix
AB).
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3.3.1.2
The Plan
100% metering and volumetric charging of all non domestic consumers in the Dublin
Region
3.3.1.3
–
Fully implemented at end 2008
–
Non domestic demand projected savings are estimated at 10Mld – 15Mld over the
planning period
–
Savings have been factored into demand projections
Water Bye-law Amendments to ensure installation of water efficient appliances in new
developments
-
Ongoing in the Dublin Region Local Authorities
-
Savings included in proposed lowering of Per Capita Consumtion (pcc) from
148l/head/day (2010) to 135l/head/day ( 2020) and 130l/head/day (2030)
-
Saving have been factored into demand projections
3.3.1.4
Awareness Campaigns
-
Ongoing (the most recent include the Tap Tips Campaign in the Dublin Region and the
Mr. Drippy Schools campaign run by Fingal County Council)
-
Savings included in proposed lowering of Per Capita Consumtion (pcc) from
148l/head/day (2010) to 135l/head/day ( 2020) and 130l/head/day (2030)
-
These campaigns are to be reinforced by the proposed introduction of Water Services
Strategic Plans (WSSPs) which specify the progression of public awareness campaigns.
The WSSPs will be implemented in 2011 (see Section 3.3.2.5).
3.3.1.5
Rainwater Harvesting
-
Local Authorities promote rainwater harvesting where practical (and through proposed
by-law amendments) – most relevant for new build & non domestic sector (see Appendix
AB)
-
Savings included in proposed lowering of Per Capita Consumtion (pcc) from
148l/head/day (2010) to 135l/head/day ( 2020) and 130l/head/day (2030)
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3.3.2
Future Potential Measures
3.3.2.1
Metering and Volumetric Charging of Domestic Customers
-
Demand projections assume implementation by 2020. By that date, all customers would
be fully metered at the property boundary and full volumetric charges would apply
-
PCC levels projected to decrease from 148l/head/day (2010) to 135l/head/day ( 2020)
and 130l/head/day (2030). This will reverse a steadily upward trend in PCC use over the
past 20 years.
-
Customer leakage projected to decrease from (2010) estimated 65 l/prop/d (litres per
property per day) to 35 l/prop/d (2020) and 25 l/prop/d (2030)
3.3.2.2
Water Bye-law Amendments to ensure installation of water efficient appliances in new
developments
-
The water consumption levels of new buildings could be reduced by the introduction of
water efficiency obligations for developers, particularly developers on public projects.
Compulsory obligations could be placed on all new public housing developments to
ensure the effective implementation of water efficient devices.
-
Similarly, Bye-laws could be introduced throughout the Dublin Region (to be specified by
the draft Dublin Region Water Services Strategic Plan - DRWSSP). The DRWSSP Plan is
scheduled come into effect by approx 2011 / 2012 and to be reviewed every 6 years (see
Section 3.3.2.6).
3.3.2.3
Greywater Re Use
-
3.3.2.4
Non domestic metering & charging will create greater incentives for reuse of greywater
Wastewater Treatment and Reuse
-
3.3.2.5
The Plan
For the domestic sector, potential savings from treatment of wastewater and reuse as
drinking water has not been factored into the demand projections on account of the
expensive technology considerations and issues of public acceptability
Water Services Strategic Plans (WSSP)
The Water Services Act 2007 provides for the preparation of Water Services Strategic Plans (WSSP)
by Water Services Authorities (Sanitary Authorities) and for their review every 6 years (maximum).
These Plans will make provisions for water conservation which require local authorities to implement
continuously improving water conservation measures.
The Dublin Region Draft WSSP has been prepared and below is an excerpt from it outlining how the it
may impact water savings:
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-
Promotion of demand management through adoption of bye-laws to encourage best
practice water management in new development and optimum water conservation among
existing domestic and non-domestic users. This involves the adoption of appropriate
bye-laws for new development, provision of information and appropriate technical
assistance for consumers, based on best international practice. Pilot projects shall be
promoted to target grey water re-use, water saving devices and rainwater recovery
towards promoting reduced water demand by consumers
-
To promote cost effective management of all aspects of the water supply service, from
source to tap, through appropriate input to the Development Planning Process and the
River Basin District (RBD) Management Plans, a representative sampling and analytical
programme, constant review and where appropriate, improvements in the management
and resourcing of water services.
The Draft WSSP will be amended to incorporate Government proposals for domestic metering and
charging when the policy is agreed and published.
3.4
CONCLUSION & RECOMMENDATIONS
The introduction of domestic metering and volumetric charging combined with leakage management
and other conservation measures will result in valuable water savings over the planning period. The
anticipated level of savings could defer the timing of the need for supplies from a new source from
2016 to 2020-2022 (see Figure 3.1).
This Plan recommends that the development of the new sustainable water supply scheme forms part
of an integrated water resource management strategy which involves adoption of lowest practicable
leakage levels and reduced domestic demand (assumes full domestic as well as non-domestic
metering and volumetric charging of customers within the Dublin Region and all areas which are
supplied with water from the new scheme).
Figure 3.1
Timing of Supply Requirements from New Source
850
Maximum Planning Scenario
(SEA Phase 2)
800
750
Minimum
Planning Scenario
Earliest Delivery Date
700
50Mld Headroom
Mld
650
Unsustainable
Production
Sustainable Production
600
550
Barrow Supplies on stream
500
450
400
2006
2008
2010
2012
2014
2016
2018
2020
2022
2024
2026
2028
2030
2032
2034
2036
2038
2040
Year
Minimum Planning Scenario
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4 WATER FRAMEWORK DIRECTIVE
In recognition of the placement of all River Basin Management Plans (RBMP) in the planning hierarchy
on the 15th July, 2010, this Plan, as it evolves, will have full regard to the final Plans for both the
Eastern River Basin District (ERBD) and the Shannon International River Basin District (ShIRBD).
In so doing, it will ensure that there is no conflict with these RBD Plans and also that any proposals
brought forward in relation to the development of a potential new water source will not jeopardise the
objectives of the RBMPs and their associated Programme of Measures (PoM).
A summary of these RBD objectives and the possible interactions with this Plan (for development of
the *Water Supply Project – Dublin Region) are outlined below.
* Water Supply Project – Dublin Region = WSP-DR
4.1
4.1.1
SHANNON INTERNATIONAL RIVER BASIN DISTRICT
Interaction / Relationship between the WSP-DR Plan and the Shannon RBMP
The Shannon River Basin Management Plan (RBMP) was reviewed to ensure that the WSP-DR Plan
does not conflict with the objectives of the Shannon RBMP.The objectives of the Shannon RBMP were
incorporated into this WSP-DR Plan, where appropriate.
Table 4.1 summarise the Relationship between the Objectives of the RBMP for the ShIRBD and the
WSP-DR Plan.
Table 4.2 summarises Interaction of the WSP-DR Plan with the Action Programme for the Shannon
RBMP.
Table 4.3 summarises the Interaction of the WSP-DR Plan with other issues for the Shannon RBMP.
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Table 4.1
DR Plan
The Plan
Relationship between the Core Objectives of the Shannon RBMP and the WSP-
Objectives of the River Basin
Management Plans
Interaction with Water Supply Project - Dublin Region
Plan
Achieve water related protected area
objectives
This WSP-DR Plan has been assessed in line with the
requirements of the Strategic Environmental Assessment
and Habitats Assessment Directives. The recommended /
preferred water supply option which will be brought
through to the formal planning process will now have to
undergo an Environmental Impact Assessment and a
stage 2 Habitats Directive Assessment. These legal
constraints will ensure that no adverse environmental
impact occurs on the environment and especially on
designated sites as a result of implementation of the
recommended / preferred water supply option. Both the
SEA and HDA reports, already undertaken, have
specified certain mitigation and monitoring measures
which have been incorporated into this (Water Supply)
Plan and which will be included into the scope of the EIA.
The specified monitoring will help to establish a detailed
background environment status and the mitigation will
help to prevent any deterioration or impact on areas
affected by the footprint of the plan. Hydrodynamic &
Water Quality Modelling will be used to regulate the
proposed abstraction methodology and ensure
compliance with the Water Framework Directive.
Prevent deterioration
The recommended / preferred option is subject to the
Planning process involving the independent planning
authority An Bord Pleanála. This will ensure that a full EIA
is carried out and the implementation of findings will
ensure prevention of any deterioration in the
environment. By incorporating large raw water external
storage into the overall water supply Plan proposed
abstractions from Lough Derg can be minimised or
ceased during low flow periods which will ensure
prevention of deterioration and full compliance with the
Water Framework Directive (WFD).
Restore good status
The WSP-DR Plan has thus far been assessed against
the back drop of the WFD Requirements (see
Environmental Report) and the robustness and flexibility
will ensure that it will not conflict with its objectives. The
WSP-DR Plan also has the potential to assist in restoring
good status to current water bodies at risk from
abstraction by making supplies available to Midlands
Local Authorities and thus possibly relieving stress on
current water bodies which are potentially at risk from
over abstraction (e.g. Lough Owel).
Reduce chemical pollution
The WSP-DR Plan does not envisage any likelihood of
creating chemical pollution. Risk management plans will
be put in place.
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Table 4.2
RBMP
The Plan
Interaction of the WSP-DR Plan with the Action Programme of the Shannon
Action Programme to Tackle Key
Issues- relating to Abstraction
Interaction with Water Supply Project-Dublin
Region
WFD requires control of surface and
groundwater abstraction
The WSP-DR Plan will be subject to the planning
process and the conditions of an abstraction licence
(1942 Water Supply Act).
Undertake an Environmental Impact
Assessment on works for the transfer of
water resources between river basins
above specified thresholds
An Environmental Impact Assessment together with a
Habitats Directive Assessment will be undertaken on
the recommended / preferred new supply proposals.
Proposed abstraction locations are currently not at
risk from over abstraction. Monitoring and mitigation
measures will be put in place to ensure
environmental sustainability. The abstraction will be
subject to an abstraction order and the planning
process which will specify the maximum allowable
abstraction rate. Provisional agreements with the
ESB have been discussed to ensure that any water
taken from Lough Derg is at the expense of water for
power generation at Ard na Crusha. A formal
Abstraction Management Plan will be developed
within the EIA / Planning Process to define the
management, monitoring and reporting regime to be
followed.
New Prior Registration and Authorisation
scheme for abstraction may be
introduced
Although the WSP-DR Plan may be in place before
the introduction of such a system it will be subject to
the planning process.
Table 4.3
Interaction of the WSP-DR Plan with the Other Issues of the Shannon RBMP
Other Issues
Interaction with Water Supply Project-Dublin
Region
Climate Change
The WSP-DR Plan developed a hydrological model of
the Shannon. This looked at a number of different
climate change scenarios (Met Eireann / ICARUS).
Sustainable abstraction regimes are achievable in all
climate change scenarios.
Invasive Species
Concerns over the transfer of invasive species:
the WSP-DR Plan has investigated the possibility of
the transfer of invasive species and various
preventative technologies have been investigated.
Extensive discussions in relation to invasive species
have taken place with various stakeholders, statutory
bodies, non-statutory bodies and NGO's.
Preventative systems (eg pressurised micro-filtration)
will be incorporated into the design and operation of
any inter-catchment transfer of water.
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4.2
The Plan
EASTERN RIVER BASIN DISTRICT
The core objectives for surface waters are as follows:
x
For High Status water bodies there is a clear objective of maintaining their status;
x
Waters of Good Status have an objective of non-deterioration;
x
The majority of waters are of less than good status and a minimum objective of achieving
good status has been set for many of these water bodies; and
x
The objective of no deterioration in existing status which applies to all waters.
The core objectives for groundwater are to:
x
Achieve Good Status in those groundwater bodies which are presently classified as being at
poor status; and
x
Protect those groundwater bodies that are currently at Good Status (i.e. maintain their good
status).
The WSP-DR Plan is not anticipated to jeopardise any of the objectives of the ERBMPs.
4.2.1
Abstractions
The ERBD River basin management plan calls for updating of the provisions of the 1942 Water
Supplies Act to better address abstraction procedures.
4.3
CONCLUSION
The implementation of the WSP – DR Plan (including particularly the proposals for regulating
abstractions which will be developed during EIA) will not impact adversely on the objectives of the
River Basin Management Plans of the SHIRBD and ERBD. The Plan will meet the regional and
national socio-economic objectives in a manner which is fully sustainable environmentally. The
Management Plan for the scheme will assist in better water quality management in Lough Derg by
improving the monitoring of raw water quality and quantity.
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5 WATER SUPPLY OPTIONS
5.1
INTRODUCTION
The water supply options which were investigated as part of the Draft Plan technical studies are
outlined schematically in Figure 5.1 . Each option is summarised below.
Figure 5.1
Water Supply Options Summary
A-Lough Ree
C-Parteen Basin
E- Lough Ree
+ Storage
G-Impoundment
- Lough Ree [Derg]
I-Fingal / Kildare
Groundwater
B-Lough Derg
D-Lough Ree +
Lough Derg
F- Lough Derg
+ Storage Options
H-Desalination
J-Liffey / Barrow
MULLINGAR
Lough
Ree
Desalination Plant
H
Wells
A
ATHLONE
G
I
Ballycoolen
E
E
D
F1
Termination
Point
Former Bogs
River
Shannon
TULLAMORE F
2
G
Impoundment
Ballymore Eustace
F
Lough
Derg
Parteen
Basin
Head
Race
Poulaphuca Lake
B
SLIEVE BLOOM
MOUNTAINS
J
PORTLAOISE
Athy
River
Barrow
Killaloe
C
Water Treatment Plant
MDW0158SK0036D14
River Shannon
ESB Ardnacrusha
Option A involves water abstraction from Lough Ree, water treatment and pumping facilities near
Lough Ree and pipelines approx 104km in length to convey treated water to the Dublin Region. This
option also has the capability of supplying treated water to Midlands Local Authorities along the
pipeline route.
Option B involves water abstraction from Lough Derg, water treatment and pumping facilities near
Lough Derg and pipelines approx 122km in length to convey treated water to the Dublin Region. This
option also has the capability of supplying treated water to Midlands Local Authorities along the
pipeline route.
Option C involves water abstraction from Parteen Basin (near Parteen weir), water treatment and
pumping facilities near Parteen Basin and pipelines approx 158km in length to convey treated water to
the Dublin Region. This option also has the capability of supplying treated water to Midlands Local
Authorities along the pipeline route.
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Option D involves water abstraction initially (Phase 1) from Lough Ree, water treatment and pumping
facilities near Lough Ree and pipelines approx 104km in length to convey treated water to the Dublin
Region. A second phase (approx 10 years later) involves abstraction from Lough Derg, treatment near
Lough Derg and pumping of treated water via pipelines 67km in length to a booster station located
approx midway between Lough Ree and Dublin. This option also has the capability of supplying
treated water to Midlands Local Authorities along the pipeline routes from Lough Ree to the Dublin
Region and from Lough Derg to the booster station location.
Option E involves raw water abstraction from Lough Ree, pumping of raw water to a “cutaway bog”
site near Rochfortbridge (owned by Bord na Mona), raw water storage facilities at the site, water
treatment and pumping facilities at the site and pipelines to convey treated water to the Dublin Region.
Overall raw water and treated water pipelines are approx 104km in length. Storage facilities will
accommodate up to 4 months average supply requirements. This option has the capability of
supplying treated water to Midlands Local Authorities from Rochfortbridge.
Option F involves abstraction from Lough Derg in combination with bog storage. Two bogs have been
identified as suitable for storage, one near Rochforbridge, Option F1, and the other near Portarlington,
Option F2.
F1 involves raw water abstraction from Lough Derg, pumping of raw water to a “cutaway bog” site near
Rochfortbridge (owned by Bord na Mona) raw water storage facilities at the site, water treatment and
pumping facilities at the site and pipelines to convey treated water to the Dublin Region. Overall raw
water and treated water pipelines are approx 127km in length. Storage facilities will accommodate up
to 2 months average supply requirements. This option has the capability of supplying treated water to
Midlands Local Authorities from Rochfortbridge.
F2 involves raw water abstraction from Lough Derg, pumping of raw water to a “cutaway bog” site near
Portarlington (owned by Bord na Mona) raw water storage facilities at the site, water treatment and
pumping facilities at the site and pipelines to convey treated water to the Dublin Region. Overall raw
water and treated water pipelines are approx 122km in length. Storage facilities will accommodate up
to 2 months average supply requirements. This option has the capability of supplying treated water to
Midlands Local Authorities from Portarlington.
Option G involves abstraction of raw water from Lough Ree during higher flow months, pumping of
raw water to a treatment plant near Dublin, pumping of excess raw water to an impoundment in the
Dublin/Wicklow mountains for usage during dry periods and delivery of treated water to a designated
termination point near Dublin. Total pipeline lengths are approx 113km in length. This option has no
capability for supplying treated water to locations en route between the Shannon and Dublin. (This
option could also be supplied from Lough Derg)
Option H involves abstraction of sea water from the Irish Sea in north Fingal, desalination of sea
water through a Reverse Osmosis (RO) desalination plant, pumping of treated water to Ballycoolen
reservoirs via 25 km pipelines and discharge of brine (from the treatment process) back into the Irish
Sea.
Option I involves abstraction of water from groundwater sources, within 80km of Dublin, and piping of
groundwater to suitable locations for treatment and introduction into public water supply systems.
Option J involves the “conjunctive use” of the River Barrow with the Upper Liffey. Approx 50% of the
Dublin Region’s water supply comes from Poulaphuca Lake on the Upper Liffey via Ballymore Eustace
Water Treatment Plant. The Liffey-Barrow “conjunctive use” option envisages abstractions of water
from the Barrow when sustainable quantities may be available (Winter / Spring) and combining these
abstractions with variable abstractions from Poulaphuca with a view to increasing the overall supply to
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Ballymore Eustace Water Treatment Plant over and above what is sustainably available from
Poulaphuca on its own.
5.1.1
Hydrological Modelling of the River Shannon
Of the ten (10) water supply options which were evaluated, seven (7) have Shannon storage locations
(Lough Ree, Lough Derg, Parteen Basin) as their principal water supply source. Flows and water
levels in the Shannon result primarily from rainfall on the catchment area; consequently flows and
water levels in Winter / Spring are generally higher than in Summer / Autumn. Downstream flows are
higher than upstream on account of the increased catchment area contributing to the flows. Longterm
average flows at Lough Derg are approx 180m3/sec (cubic metres per second) compared to average
flows at Lough Ree of approx 100m3/sec. (The maximum proposed abstraction for Dublin is 4m3/sec at
2030 – 2040 including allowances for peaks and contingencies).
A Hydrological Model of the Shannon was developed in order to identify and evaluate abstraction
impacts on the Shannon’s storage, lake levels and flows at various Shannon locations. The model can
simulate the impacts of water abstraction on water levels and flows in the Shannon for a
representative range of historic and future climate change scenarios.
The Shannon’s management and operational regime as set out in ESB’s “Regulations & Guidelines for
Control of the River Shannon” are an integral part of the modelling operation. The Shannon is
managed by ESB and Waterways Ireland (WI) in accordance with these Regulations and Guidelines.
The Regulations, which are reviewed regularly, have been in place since the early 1970’s and they
represent an operational best-fit for meeting various (sometimes competing) stakeholder interests on
the Shannon, in particular:
x
Navigation
x
Landowner and callows flooding
x
Water quality & water supply
x
Fisheries
x
Tourism
x
Agriculture
x
Power generation activities (including Dam & Embankment safety)
In addition to modelling the ESB / WI operational regime, the model can also assess the impacts of
abstractions on water residence times in lakes and can demonstrate how the operation of control
structures (weirs, sluices and dams) can be optimised to increase storage in lakes which in turn can
facilitate abstractions thereby minimising potential abstraction impacts.
The model operates on Danish Hydraulic Institute, MIKE NAM and MIKE 11 suite of modelling
software. This software, which enables assessment of abstraction impacts on the Shannon River and
lake system, is in widespread use worldwide for similar applications. Surveying data, operational data
and records were obtained from OPW, ESB, Waterways Ireland and the Shannon River Basin Project
which ensured the model’s timely development. Modelling results are summarised in Appendix B .
The modelling simulations concentrated on the statistically driest years over the recent period of
record particularly 1989, 1995 and 2000. Most years can be modelled since good quality weather data
is available from Met Eireann. For illustration purposes 1995 has been selected – results for 1989 and
2000 are contained in Appendix B.
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Two climate change scenarios (ICARUS and Met Eireann’s C4i) were modelled. Description of climate
change assessment methodologies and modelling results are contained in Appendix B. Options
involving Lough Derg and Parteen Basin were not specifically modelled for climate change since
abstractions from these locations assume that power generation at Ardnacrusha is modified (with ESB
Agreement) to compensate for the abstractions thereby neutralising impacts on water levels. Potential
impacts resulting from climate change would also be compensated for in a similar manner through
modifications to Ardnacrusha’s operations. Compensating for abstraction and climate change in this
manner enables operational lake levels in Lough Derg and Parteen Basin to be maintained as at
present.
5.1.2
Phased Water Supply Requirements from the New Supply Source
Demand projections for the Dublin Region (Section 2) indicate a requirement for water supplies from a
new source to supplement supplies from existing sources by approx 2020. Existing sources (Liffey,
Vartry, Dodder, Fingal & Kildare Groundwater Sources) will be developed to their sustainable supply
limits by approx 2014 / 15. The sustainable production of existing Dublin Region sources (627Mld) can
meet average demand up to approx 2020.
The phasing of water supplies from the new source will commence with an initial base flow, currently
estimated at minimum 60Mld and maximum 100Mld. In order to manage demand growth risk and
improve economic efficiency, total installed infrastructure capacity will be limited initially to 250Mld in
the first phase (2020). A second phase of infrastructure development (approx 15 years after Phase 1)
will add an increase in capacity of 100Mld, bringing the total installed capacity to 350Mld by approx
2035.
Infrastructure development proposals and associated capital costs reflect a phased approach to the
provision of gradually increasing quantities of water supplies to match demand growth.
5.1.3
Technical Evaluation of Water Supply Options
The technical evaluation of water supply options involved the following assessments:
1) Assessment (through Hydrological Modelling & specialist studies) of potential sustainable
availability of 350Mld from the source locations at various times throughout the year over a
range of historic climatic conditions including future climate change scenarios. In the case of
Shannon options, potential sustainable availability of water was primarily determined with
reference to the constraints contained in the Shannon Operating Regulations & Guidelines.
Hydrodynamic & Water Quality Modelling during EIA will determine details of abstraction
regimes. Potential sustainable availability of water supplies also implies ongoing and
continuous sustainable availability of sufficient water for local supply requirements in the short,
medium and longterm.
2) Identification and development of infrastructure requirements to meet phased demand growth
including:
-
Abstraction and Raw Water Pumping facilities
-
Raw Water Pipelines
-
Water Treatment Plant (s)
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-
Treated Water Pipelines and Pumping facilities
-
Storage facilities
-
Integration and connection of new water supplies into the Dublin Region water
distribution network
-
Routing and Site Selection
5.1.4
Routing and Site Selection
The pipeline corridor selection process for all options involved identification of the shortest length route
corridors (2km width) between the off-take and termination points, which have least environmental
impact and are the most economic route corridors for future construction and operation of a pipeline
(or pipelines). The routing and site selection was consistent with the constraints of the overall design
philosophy particularly with respect to elevation profiles, operating pressures and optimisation of
overall operational requirements.
Major constraints considered:
x
Suitable location for abstraction and raw water pumping station.
x
Suitable sites for location of Treatment Works
x
Suitable sites for storage of raw water (some options)
x
Suitable sites for future Booster Stations (if required)
x
Suitable delivery point (Dublin)
x
Suitable water supply delivery points (Midlands Local Authorities)
x
Avoidance of Major Natural Constraints – Mountains / Lakes / Forests / Bogs / Mineral
Extraction Areas / Rock
x
Avoidance or minimisation of impacts on:
National Heritage Areas (NHA)
Special Protection Areas (SPA)
Special Areas of Conservation (SAC)
Known Archaeological Sites
x
Avoidance of:
Existing Developments
Planned Developments
Motorways, High Voltage Electricity Pylons & Gas Transmission Pipelines
x
Compliance with topography / elevation considerations consistent with the overall design
philosophy of minimising pumping energy and optimisation of operational criteria.
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5.1.5
The Plan
Economic Evaluation of Water Supply Options
The economic evaluation of water supply options involved the following approach:
1) Establishing the Net Present Value (NPV) of Capital Costs including infrastructure renewal
over an assumed 25 year operating period using a discount value of 5%
2) Matching infrastructure development to demand growth on a phased basis where practical
3) Establishing the NPV of Operating Costs over an assumed operating period of 25 years
4) Establishment of residual value after 25 years of operation
5) Calculation of water quantities delivered over a 25 year operational lifetime
6) Calculation of average cost (per m3) of water delivered to the Dublin Region over the assumed
25 year operating period.
5.1.6
Environmental Assessment
An Environmental Report (and Habitats Directive Assessment) on each of the water supply options
was prepared in parallel with th2 2008 draft Plan as part of the Strategic Environmental Assessment
and Habitats Directive Assessment process.
Each option was assessed against the various sustainability criteria.
5.1.7
Public Consultation
Formal public consultation under SEA Phase 2, in respect of the ten water supply options which were
assessed, commenced on 24 November 2008 and concluded on 27 February 2009. Extensive
feedback was received from stakeholders and the general public during the consultation period and
this feedback has been analysed in order to inform the decision making process and the overall
planning and development of the Dublin / Mid East / Midlands Regional water supply project.
During the SEA process, in excess of 30 presentations were made to a variety of stakeholders and
considerable feedback was received during the associated “Question & Answer” sessions which were
minuted and recorded. The project website registered in excess of 2,500 “hits”. At the end of the
formal public consultation period on 27 Feb 2009, over 50 formal submissions (written & email) had
been received from stakeholders and the general public.
Feedback from stakeholders has been analysed and categorised. Comments and recommendations
received during this process have been incorporated, where appropriate, into this Plan. A
comprehensive report on all issues raised in relation to the (Draft) Plan during SEA public consultation
is available in the Public Consultation Report;
www.watersupplyproject-dublinregion.ie / publicconsultationreport.
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6 LOUGH REE OPTIONS - EVALUATION SUMMARY
Water supply options with Lough Ree as their water supply source are illustrated schematically in
Figure 6.1 below. Options A, D, E and G were assessed against the following criteria:
x
Technical
x
Environmental
x
Socio – Economic
x
Economic
The assessment results are summarised in this section.
Figure 6.1
Lough Ree Options
LOUGH REE:
A-Lough Ree
D-Lough Ree +
Lough Derg
E- Lough Ree
+ Storage
G-Impoundment
- Lough Ree [Derg]
MULLINGAR
Lough
Ree
A
E
ATHLONE
D
Termination
Point
Former Bogs
River
Shannon
TULLAMORE
G
Impoundment
Lough
Derg
PORTLAOISE
Water Treatment Plant
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6.1
TECHNICAL ASSESSMENTS
6.1.1
Hydrological Model
The Plan
A Hydrological Model of the Shannon was developed in order to identify and evaluate abstraction
impacts on Shannon lake levels and flows at various locations. The model can simulate the impacts of
water abstraction on water levels and flows in the Shannon for a representative range of historic
climatic conditions and future climate change scenarios.
The Shannon’s flows and lake levels in the general vicinity of Lough Ree are managed and controlled
through the operation of the sluices which are located on Athlone Weir. The sluices are managed and
operated by ESB and Waterways Ireland (Shannon Statutory Operators) in accordance with rules and
guidelines which are set out in the ESB document “Regulations & Guidelines for Control of the River
Shannon”. The Regulations & Guidelines prescribe the lake levels (and indirectly the flows) that must
be implemented and maintained in Lough Ree at different stages throughout the year.
The Regulations require that Lough Ree’s water levels are drawn down gradually from April to October
whilst maintaining specified minimum operating levels which vary over the (7 month) period. The
drawing down of lake levels is undertaken to ensure that the lake’s storage capacity is optimised for
flood management. Increasing the storage capacity of the lake provides a buffer effect against the
impacts of potential seasonal flooding on lands adjoining the lake and downstream of Athlone on the
Shannon callows. Lake levels are drawn down by opening the sluices on Athlone Weir thereby
increasing the downstream flows from the lake (provided downstream levels permit). Draw-downs from
the lake are restricted to ensure that minimum navigation levels are maintained over the relevant
periods.
Lough Ree
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Athlone Weir and Sluices
6.1.2
6.1.2.1
Modelling Conclusions for Options A, D, E and G – Lough Ree
Water Levels
Potential abstractions (for water supply) from Lough Ree could only be achieved within the water
levels specified in the ESB Regulations in a situation where sluice operations are modified / optimised
to facilitate the proposed abstractions. In reality this would require reducing the rates of draw-down
through the sluices, resulting in greater retention of water in the lake which in turn would facilitate
water abstraction proposals but at the expense of increasing seasonal flooding risk around Lough Ree
and downstream on the Shannon callows. Increasing seasonal flooding risk on the Shannon callows
could give rise to significant environmental impacts. Lough Ree and the Shannon callows are Special
Areas of Conservation (SAC)
Abstractions from Lough Ree, in a situation where sluices are operated as at present, could result in
occasional breaches of current Regulations in respect of specified minimum lake levels during dry
years. This would be unacceptable to environmental and navigation interests.
6.1.2.2
Water Flows
Modelling of abstraction impacts on water flows indicated that the duration of the minimum flow
(12m3/sec) periods could extend during dry periods by over 20 days (70 days vs 46 days for 1995).
Increasing durations of minimum flow periods in the Shannon callows (SAC) could give rise to
significant environmental impacts.
Modelling results for abstraction impacts for Options A, D, E and G are summarised in Table 6.1.
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Table 6.1
The Plan
Modelling Results Summary
Abstraction
Impacts
Water Levels
Lough Ree
Seasonal
Flooding Risk
Downstream
Flow Durations
through
Shannon
Callows
Option A
Option D
Option E
Option G
Potentially
significant impacts
for continuous
350Mld
abstractions in dry
periods unless
existing sluice
operations are
modified.
As per Option A
but marginally
less significant
impacts
Not likely to be
significant but
extensive storage
required for
abstractions in
summer and
autumn periods.
May still require
marginal change
to existing sluice
operations which
would be difficult
to achieve.
As per Option E
Modification to
sluice operations
will give rise to
increased risk of
seasonal flooding.
Option A is higher
risk than Options
D,E or G
Marginally less
risk than Option A
Not likely to be
significant but
extensive storage
would be required
to cater for
abstractions in
summer and
autumn periods
As per Option E
Option A has
longest period of
extended
minimum flow
durations resulting
from abstraction.
In excess of 20
additional days in
dry periods
Marginally less
extended
durations than for
Option A
Not likely to be
significant but
extensive storage
would be required
to cater for
abstractions in
summer and
autumn periods
As per Option E
6.2
ENVIRONMENTAL ASSESSMENTS
6.2.1
Strategic Environmental Assessment – Environmental Report
The principal environmental impacts which potentially could arise from implementation of Lough Ree
Options are summarised in Table 6.2 below. These potential environmental impacts have been
assessed separately. Details of the assessments are available in the Environmental Report which was
prepared during Strategic Environmental Assessments of these water supply options and which were
tabled for public consultation during the Nov 08 to Feb 09 period under the SEA process.
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Table 6.2
The Plan
Environmental Impact Summary of Lough Ree Options
Issue
Environmental Impact
Flows
Abstraction during dry years will result in extended durations of
minimum downstream flow periods. Extended low flow periods
downstream of Athlone could potentially have adverse impacts on
biodiversity, flora and fauna in the Shannon callows and fisheries
in the River. The Shannon Callows are designated as a Special
Area of Conservation (SAC).
Water Levels
Abstractions during dry periods could occasionally result in lake
levels less than specified in ESB Regulations & Guidelines under
current sluice operational arrangements. Optimisation of sluice
operation to facilitate abstraction would likely result in lake levels
in compliance with Regulations but would also increase seasonal
flooding risk around Lough Ree and downstream on the callows.
Seasonal flooding (summer / autumn) would impact negatively on
agricultural systems and create adverse environmental impacts on
the callows.
Residence Times
Abstraction from Lough Ree will result in marginal increases in
residence times of water in Lough Derg during dry years. The
potential increases could significantly impact on algal growth.
Further studies and data gathering would be required to assess
properly but these may also prove to be inconclusive.
6.2.2
Habitats Directive Assessments
Assessments under the Habitats Directive have effectively established that Lough Ree Options are
unlikely to be environmentally sustainable. Increasing seasonal flooding risk to facilitate abstraction is
potentially endangering the ecology within the SAC. Likewise, increasing the durations of minimum
flow periods during low flows could also endanger the ecology of the Shannon callows SAC. The
application of the “precautionary principle” effectively means that planning consent for any Lough Ree
option would be contrary to HDA.
6.3
SOCIO ECONOMIC ASSESSMENT SUMMARY
Abstraction from Lough Ree can only be undertaken within the water levels specified in ESB
Regulations by modifying the current sluice operation at Athlone. The current sluice operational regime
seeks to provide a balance between the competing interests of navigation and seasonal flood
mitigation on behalf of riparian owners around Lough Ree and downstream on the Shannon Callows.
Modification to the sluice operations will increase flooding risk with potential adverse impacts on
agriculture and on the ecology of the Shannon callows SAC.
Continuous abstractions without modifying sluice operations would result in breaches of lake levels in
dry periods. This would impact on navigation rights and have potential negative environmental
implications.
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Abstractions, with or without sluice operation modifications, will give rise to increased durations of
minimum flows during dry periods (approx 50 days to 70 days in 1995). These extended minimum flow
durations have the potential for adversely impacting the ecology of the Shannon Callows SAC.
Mitigation of seasonal flooding risk and extended durations of minimum flow periods is possible
through varied abstractions and / or use of external storage but at considerably increased expense on
account of the extent of external storage which would be required (minimum 4 months).
6.4
ECONOMIC ASSESSMENT SUMMARY
There are a number of phasing scenarios available for optimising infrastructure development in line
with demand growth. Capital and operating cost ranges for water supply options are based on
construction of pipelines initially for the long-term capacity (350Mld), while the treatment, pumping
facilities and storage (where relevant) are designed for the maximum capacity of each separate phase.
Results are summarised in Table 6.3 below in which the cost ranges represent the Net Present Value
(NPV) of the various water supply schemes over a 25 year operational life using a discount rate of 5%.
Estimates are based on 2010 costs for labour / materials / energy etc
Table 6.3
6.5
Summary of Capital / Operating / Whole Life Costs
Option
Option A
Option D
Option E
Option G
NPV CAPEX
€440m – €480m
€450m - €490m
€530m - €580m
€570m - €620m
NPV OPEX
€100m - €130m
€ 110m - €140m
€120m - €150m
€120m - €160m
Whole Life Cost
(25 years)
€540m - €610m
€560m - €630m
€650m - €730m
€690m - €780m
WLC / Volume
€.27/m3- €.30/m3
€.27/m3- €.30/m3
€.32/m3- €.36/m3
€.45/m3- €.50/m3
SUMMARY LOUGH REE WATER SUPPLY OPTIONS (A, D, E AND G)
Lough Ree covers an area of 100km2 and is the closest Shannon location to the Dublin Region –
approx 104km (65 miles). Average Shannon flows at Athlone are approx 100m3/sec. Minimum flow is
12m3/sec and maximum flood flows can reach 350m3/sec. Water levels in Lough Ree and flows
downstream of Athlone are controlled by ESB in conjunction with Waterways Ireland (WI) through the
operation of sluices located on Athlone Weir. The sluices are operated in accordance with the ESB
document ‘Regulations & Guidelines for Control of the River Shannon’. The main focus of the
Regulations is to achieve balance between the competing stakeholder interests – navigation and
flood prevention / mitigation – whilst maintaining a minimum downstream flow (12m3/sec) at all times.
The current implementation of the Regulations is not to the full satisfaction of the various stakeholder
groups and this gives rise to local disagreements between stakeholders and ESB / WI in both dry
periods and flood periods. There is little likelihood of any significant change to sluice operations since
any change will more than likely adversely impact one stakeholder interest at the expense of others.
Modelling studies have identified that technically there is sufficient water quantity available in Lough
Ree to provide Dublin with up to 300Mld. In order to achieve this quantity of water on a continuous
basis, whilst complying with the minimum navigation levels specified in the Regulations and
maintaining minimum downstream flows, it would be necessary to change the operation of the sluices
and retain greater levels of water above the minimum navigation levels in the lake to facilitate the
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The Plan
abstraction. This would increase flooding risk on Lough Ree and the Shannon Callows SACs (Special
Areas of Conservation) and as such could give rise to significant environmental impacts during
seasonal (summer / autumn) flooding conditions. The flood history on the Shannon, for example
recent severe flooding in December, 2009 illustrates starkly the significance of this issue.
Abstractions from Lough Ree, without changing the current sluice operations specified in the
Regulations, would result in occasional breaches of Regulations in respect of specified minimum lake
levels during dry years based on the detailed modelling and using historic ‘dry’ year data. This would
adversely impact navigation interests and other environmental / socio-economic interests of the
catchment community.
In addition to lake level issues, abstractions (for Dublin) during dry years would result in extended
durations of minimum flow periods. Extended low flow periods downstream of Athlone could
potentially have adverse impacts on biodiversity, flora and fauna in the Shannon Callows and
fisheries in the River. There would also be some impact on flow and residence times in Lough Derg,
downstream.
The results of the modelling analysis and environmental assessments conclude that technically the
water is available in Lough Ree but that it is not possible to abstract it in compliance with the
Regulations without creating conditions which could give rise to significant environmental impacts on
protected SACs. The National Parks & Wildlife Service (NPWS) advised during SEA Phase 2 public
consultation that Options from Lough Ree were highly likely to be assessed as being in breach of the
Habitats Directive. Such abstractions, particularly direct abstractions with no storage, may also
conflict with the EU Water Framework Directive objectives to the extent that they could potentially
impact adversely on water quality.
Lough Ree Options A and D are the least cost Shannon options, but they both have the potential to
give rise to significant adverse environmental and socio economic impacts. These considerations
were factored into the option evaluation process since they impact adversely on the environmental
sustainability of the options. The ‘Precautionary Principle’ of environmental management strongly
suggested that the adverse impacts of these options be avoided, especially where more sustainable
options exist at marginal additional cost.
Lough Ree Options E and G largely overcome the shortcomings of Lough Ree Options A and D but
at considerable additional expense due to the extent of raw water storage which would be required
(minimum 4 months). Even with the additional expense, the issues which arise, in relation to the
satisfactory operation of sluices on Athlone Weir would remain integral to scheme approval (control of
water levels and flows as part of an operational plan for Lough Ree).
The additional expense (of Options E & G) is also such that northern Lough Derg Water Supply
Options (see Section 7) involving an additional 20 km of pipelines and 2 months storage, are
economically equivalent to Lough Ree Options E and G. However, Options involving Lough Derg are
significantly better at meeting the criteria for sustainable development because of the greater
availability of water (80% increase on Lough Ree) and the higher degree of water management and
control which is available through the operation of Parteen Weir and Ardnacrusha Power Station. In
these cases, the current operational regime is unequivocal and lies fully within the remit of the ESB,
which in turn is adequate for security of future water supplies without major revision.
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7 LOUGH DERG / PARTEEN BASIN OPTIONS – EVALUATION
SUMMARY
Water supply options with Lough Derg / Parteen Basin as the water supply source are illustrated
schematically in Figure 7.1 below. Aerial photography of Lough Derg and Parteen Basin are shown in
Figure 7.2 and Figure 7.3 respectively. Options B, F and C were assessed against the following
criteria:
x
Technical
x
Environmental
x
Socio – Economic
x
Economic
The assessment results are summarised in this section.
Figure 7.1
Lough Derg / Parteen Basin Options
LOUGH DERG:
B-Lough Derg
C-Parteen Basin
PARTEEN BASIN:
Lough
Ree
F- Lough Derg
+ Storage Options
MULLINGAR
ATHLONE
F1
TULLAMORE
River
Shannon
F2
Former Bogs
Termination
Point
F
Lough
Derg
Parteen
Basin
Head
Race
B
SLIEVE BLOOM
MOUNTAINS
PORTLAOISE
Killaloe
C
Water Treatment Plant
River Shannon
ESB Ardnacrusha
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Figure 7.2
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Figure 7.3
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Killaloe / Parteen Basin / Parteen Weir
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The Plan
7.1
TECHNICAL ASSESSMENTS
7.1.1
Modelling of Abstraction Impacts from Lough Derg / Parteen Basin
Sustainable water availability from Lough Derg / Parteen Basin has been identified by the Shannon
Hydrological Model. The model simulates the water levels and flows in the Shannon system for a
range of operating conditions, historic climatic conditions and future climate change scenarios.
Storage levels, lake levels and flows in Lough Derg / Parteen Basin are primarily managed and
controlled through the operation of Parteen Weir which regulates water flows to Ardnacrusha Hydro
Power Station (Figure 7.4, Figure 7.5 and Figure 7.6). The Shannon is managed and operated by
ESB (and Waterways Ireland) in accordance with rules which are set out in the “Regulations &
Guidelines for Control of the River Shannon”.
Figure 7.4
Parteen Weir
Old River
Shannon
Headrace to
Ardnacrusha
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The Plan
Figure 7.5
Ardnacrusha Hydropower Station
Figure 7.6
Headrace to Ardnacrusha
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7.1.2
The Plan
Water Levels in Lough Derg / Parteen Basin
Lough Derg / Parteen Basin water levels are controlled by the operation of sluices on Parteen Weir.
The sluices control the water supply into the Ardnacrusha headrace (for power generation) and also
the water flows in the Shannon River downstream of Parteen Weir. The ESB “Regulations and
Guidelines for Control of the River Shannon” prescribe the water levels which must be implemented
and maintained in Lough Derg / Parteen Basin under a range of operating conditions at Ardnacrusha.
Minimum and maximum operational water levels have been established by ESB for management of
Ardnacrusha / the Headrace / Parteen Basin and Lough Derg. Operation in accordance with the
agreed levels ensures:
x
Dam and Embankment Safety (as a top priority)
x
Optimisation of Generation Efficiency
x
Minimisation of Flooding Impacts
x
Navigational Access
x
Minimisation of impacts on Water Quality / Fisheries
7.1.3
Flows in Lough Derg / Parteen Basin
The whole Shannon outflow from Lough Derg / Parteen Basin (during non-flood periods) is used for
Power Generation at Ardnacrusha, apart from:
x
Compensation flows to the “old” River Shannon channel at Parteen Weir (10m3/sec
minimum)
x
The flow through the fish pass at Ardnacrusha (0.7m3/sec)
x
Water abstraction by Limerick City Council (0.40 m3/sec taken from the Headrace Cloonlara)
Longterm average flow in Lough Derg / Parteen Basin is approx180m3/sec. See Figure 7.7.
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Figure 7.7
The Plan
Existing Average Flows and Abstractions
Shannon Flows – Parteen Basin/Weir – Ardnacrusha/Shannon River
Parteen
Basin
Without Dublin Abstraction:
Parteen Weir
Long term average:
~170 m3/s
Headrace
Compensation
flow: 10 m3/s
9.3 m3/s – 600kW turbine
0.7 m3/s – Fish Pass
Shannon
River
O’Briensbridge
ESB
Ardnacrusha
Minimum flow:
~10 m3/s
Cloonlara:
0.4m3/s
Castleconnell
Doonass Falls: 1.3m3/s
Clareville WTP
Planned capacity: 1.7 m3/s
Limerick
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The four turbines at Ardnacrusha can generate up to 92MW of power at maximum or near maximum
throughput (4 turbines @ § 100m3/sec each § 400m3/sec). Water levels at Ardnacrusha, Parteen
Basin and in Lough Derg are managed in order to achieve maximum generation efficiencies whilst
simultaneously ensuring that the rate of drawdown and operational levels are controlled within agreed
limits.
During flood periods, Ardnacrusha generates power at the maximum flow rate through the plant
(400m3/sec) and the excess flood-flows (potentially greater than 300m3/sec) are discharged from
Parteen Weir to the “old” River Shannon channel thereby giving rise to potential flood conditions.
Because of restrictions in the channel at Killaloe (upstream of Parteen Basin – see Fig 7.3), flood flows
exiting from Lough Derg can also create back-up flooding upstream.
ESB have generation rights to Shannon waters and must be compensated for abstractions of water
from the catchment which otherwise could have been used for power generation.
7.1.4
Modelling Results Summary
Modelling simulations assumed that Ardnacrusha generation activities are marginally modified (with
ESB approval & agreement) to reflect the approx 1% – 2% reduction in flows which would arise from
abstractions from the northern section of Lough Derg or from the southern section of Parteen Basin
(see Figure 7.8).
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Figure 7.8
The Plan
Schematic of Average Water Flows Lough Derg / Parteen Basin
Lough Derg / Parteen Basin – Average Flows & Abstractions
No Abstraction
Options B&F with
Abstraction
Option C with
Abstraction
|
4m3/s
Lough
Derg
Lough
Derg
Lough
Derg
180m3/s (avg)
176m3/s (avg)
180m3/s (avg)
Killaloe
Killaloe
Parteen
Basin
170m3/s
(avg)
Ardnacrusha
Parteen
Basin
Parteen Weir
10m3/s (min)
Limerick
166m3/s
(avg)
Ardnacrusha
Killaloe
Parteen
Basin
Parteen Weir
10m3/s (min)
Limerick
166m3/s
(avg)
Ardnacrusha
|
4m3/sWeir
Parteen
10m3/s (min)
Limerick
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7.1.4.1
Water Levels
Lough Derg’s water levels are normally managed within a narrow operating band (460mm) - minimum
normal operating level of 30.40mODM* and maximum normal operating level of 30.86mODM. Over
the period of record, lake levels have occasionally been lowered to the navigation limit (30.10mODM)
when ESB national power generation output required additional operational capacity. Over the years,
the scale of output from Ardnacrusha (max 92MW) has become less significant in a national context
as overall generation output capacity has increased (§ 5000MW) and continues to rise. Consequently,
current operational practice at Ardnacrusha maintains lake levels within the normal operating band.
Recorded water levels in any year for Lough Derg and Parteen Basin are the net result of inflows to
Lough Derg, rainfall, evapotranspiration and outflows from Parteen Basin, 95% of which are diverted
at Parteen Weir into the headrace canal for generation purposes at Ardnacrusha. If Ardnacrusha
generation output is modified, with ESB approval, (approx 1% to 2%), to compensate for Dublin
abstraction flows, the resultant water levels will remain the same as for the non-abstraction recorded
levels. Consequently recorded levels and simulated abstraction levels are practically identical between
pre and post abstraction regimes in this scenario.
*ODM = Ordnance Datum Malin
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7.1.4.2
The Plan
Flows
Flows through Lough Derg / Parteen Basin, in the northern Lough Derg abstraction scenario, will be
reduced by the amount of water abstracted (see Figure 7.8 Options B & F). The reduction in flow
through the lake will not give rise to lower lake levels since Ardnacrusha generation activities are
modified to compensate for the marginal reduction in flows as a result of abstraction. The reduced flow
through the lake will give rise to a marginal increase in water residence times in the case of the
abstraction proposal from the northern part of Lough Derg.
7.1.4.3
Residence Times
Residence times of water in Lough Derg were modelled to identify increases which would arise as a
result of abstraction. Residence times in lakes vary over the yearly weather cycle ranging from short
durations in high flow winter type conditions to longer periods in dry summer flow conditions. The
modelling forecasts that abstraction could increase residence times in dry years by 10% to 15%.
Water Supply Option F involves increased abstractions in high flow periods, storage of raw water and
reduced Shannon abstractions in low flow periods. Increased residence times of water in Lough Derg
during low flow periods can be reduced or eliminated through the incorporation of external (bog)
storage into the abstraction proposals (as per Option F).
For Water Supply Option C, increased residence times as a result of abstraction do not arise because
of the downstream location of the Option C proposed abstraction point.
7.1.5
Modelling Results Conclusion
Abstractions from Lough Derg / Parteen Basin are technically feasible. Abstractions will not result in
changes to operational water levels since Ardnacrusha generation activities (with ESB approval) can
be modified to compensate for marginal reduction in flows which will arise as a result of abstraction.
Reductions in flow through Lough Derg, as a result of abstractions from northern Lough Derg without
external (bog) storage, could give rise to marginal increases in low-flow residence times in dry years.
The residence time increase can be minimised or eliminated through the incorporation of external
storage into the abstraction proposals.
7.2
ENVIRONMENTAL ASSESSMENTS
The principal environmental impacts which potentially arise from implementation of Lough Derg
(Option B), Lough Derg + Cutaway Bog Storage (Option F) and Parteen Basin (Option C) are
summarised in Table 7.1, Table 7.2 and Table 7.3. These potential environmental impacts have been
assessed separately in much greater detail. These details are included in the “Environmental Report”
which was prepared as part of the Strategic Environmental Assessment of these water supply options
and is available on www.watersupplyproject-dublinregion.ie.
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Table 7.1
The Plan
Environmental Impact Summary – Option B – Lough Derg (No bog storage)
Issue
Environmental Impact
Water Levels L Derg
Not impacted by abstraction due to compensating effect of
marginally reduced intake at Ardnacrusha for power generation.
Flows
Reduction in flows through the lake as a result of abstraction will
not reduce levels in lake but could give rise to marginal increases
in residence times during low flow periods
Residence Times
The residence time increase can be minimised or eliminated
through the incorporation of external storage into the abstraction
proposals (Option F = Option B + Storage)
Table 7.2
Environmental Impact Summary – Options F1 & F2 – Lough Derg + Storage
Issue
Environmental Impact
Water Levels L Derg
No anticipated adverse impacts
Low Flows
No anticipated adverse impacts
Residence Times
No anticipated adverse impacts as a result of storage
Storage optimises system operation and minimises marginal
increases in residence times during low flow periods.
Option F2 (Garryhinch Bog) is preferable to Option F1
(Derrygreenagh Bog) – the pipeline route is shorter and
Garryhinch is technically preferable for storage construction due to
geological considerations.
Bog Storage
Potential to create new habitats and amenity areas in keeping with
Bord na Mona's environmental management plans. This option will
have a positive impact on land-use, landscape, visual amenity,
tourism and amenities.
Table 7.3
Environmental Impact Summary – Option C – Parteen Basin
Issue
Environmental Impact
Flows
No anticipated adverse impacts
Water Levels
No anticipated adverse impacts
Residence Times
No anticipated adverse impacts
7.2.1
Habitats Directive Assessments
Assessments under the Habitats Directive have established that all Lough Derg / Parteen Basin
Options are likely to be environmentally sustainable and are unlikely to have significant adverse
impacts on designated sites (SACs). ‘Residence time increase’ issues for Water Supply Option B
would need further investigation at EIS stage (which may still prove inconclusive due to the
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complexities involved). The residence time impacts can be largely eliminated by use of external (bog)
storage.
7.3
SOCIO ECONOMIC ASSESSMENT SUMMARY
Abstractions from Lough Derg / Parteen Basin will not result in changes to operational water levels
since Ardnacrusha generation activities (with ESB approval) can be modified to compensate for
marginal reductions in flows which will arise as a result of abstraction. As a result Lough Derg levels
will continue to be controlled within the current normal operating range of 30.4mODM to 30.86mODM.
There are no adverse impacts on navigation resulting from abstraction.
Reductions in flow through Lough Derg, as a result of abstractions from northern Lough Derg without
storage, could give rise to increases in low-flow residence times in dry years. The increases can be
minimised or eliminated through the incorporation of external storage into the abstraction proposals.
The increased residence times could give rise to some water quality issues and would need further
investigation to be more conclusive.
Abstractions involving Lough Derg + Storage and Parteen Basin have no adverse socio economic
impacts. The storage proposals have the potential to contribute to socio economic benefits in the
Midlands through the creation of Eco Park Amenity.
7.4
ECONOMIC ASSESSMENTS
There are a number of phasing scenarios available for optimising infrastructure development in line
with demand growth. Capital and operating costs of Options have been based on construction of
pipelines initially for the long-term capacity (350Mld), while the treatment, pumping facilities and
storage (where relevant) are designed for the maximum capacity of each separate phase.
Results are summarised in Table 7.4 below in which the costs represent the Net Present Value (NPV)
of the various water supply schemes, over a 25 year operating lifetime, with a discount rate of 5%.
Estimates are based on 2008 costs for labour / materials / energy etc
Table 7.4
Summary of Capital / Operating / Whole Life Costs
Option
Option B
Option F1
Option F2
Option C
NPV CAPEX
€490m – €540m
€530m - €570m
€520m - €560m
€590m - €650m
NPV OPEX
€110m - €140m
€120m - €160m
€120m - €160m
€130m - €170m
Whole Life Cost
(25 years)
€600m - €680m
€650m - €730m
€640m - €720m
€720m - €820m
WLC / Volume
€.30/m3- €.34/m3
€.32/m3- €.36/m3
€.32/m3- €.36/m3
€.35/m3- €.41/m3
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7.5
The Plan
SUMMARY LOUGH DERG / PARTEEN BASIN OPTIONS (B, F2 AND C)
Lough Derg is the largest lake on the Shannon River with an area of approx 120km2. The average
flow in Lough Derg is approx 180m3/sec. Minimum flows into Lough Derg are approx 10m3/sec –
15m3/sec and flood flows can reach 800m3/sec. The northern part of Lough Derg is approx 124km
from Dublin. Lough Derg’s water levels are controlled by the operation of sluices on Parteen Weir
which is located at the downstream exit from Lough Derg / Parteen Basin. The sluices control the
water supply into the Ardnacrusha headrace (approx 170m3/sec average) and also the water flows in
the old Shannon River channel downstream of Parteen Weir (minimum 10m3/sec). In turn these flows
dictate hydraulic levels and gradients upstream through Killaloe and Lough Derg. In this way, ESB
can control levels in Lough Derg practically regardless of inflow rates.
As part of ESB’s power generation activities, Lough Derg’s water levels are normally managed within
a narrow operating band (460mm). In the past, lake levels have occasionally been lowered to the
navigation limit (300mm below the lower operating limit) when ESB national power generation output
required additional operational capacity. Current operational practice restricts lowering the level
below the lower operating limit other than in emergency situations.
Lake levels at any particular time are the net result of inflows to the lake, rainfall & evapotranspiration
and outflows from the lake. Ninety five percent (95%) of the outflows are diverted at Parteen Weir into
the headrace canal for generation purposes at Ardnacrusha, underlining the fact that this parameter
is the primary one governing lake levels. If Ardnacrusha generation output is modified marginally,
with ESB approval, (approx 1% to 2%), to compensate for Dublin water abstractions, the resultant
lake level will remain the same as for the non-abstraction recorded levels. Proposals to abstract
water from Lough Derg were investigated on the basis of entering agreement with ESB to reduce
their generation activities (1% - 2%) to cater for the Dublin inter-catchment water transfer. ESB cooperate with water authorities throughout Ireland in relation to water supplies from their reservoirs in
this manner, for example at Poulaphuca (Liffey) and Inniscarra (Lee). Compensation is payable to
ESB for loss of generation capacity resulting from these water supply activities.
A number of Water Supply Options with Lough Derg / Parteen Basin as their water supply source
were investigated. Two options involved abstraction from the northern end of Lough Derg which is the
closest location of Lough Derg to the Dublin Region. One option (Option B) involved water treatment
at Lough Derg and direct supply of treated water to Dublin (124km) with no significant intermediate
storage involved. The other option (Option F2) involved pumping of raw water to large scale storage
facilities in (Bord Na Mona owned) Garryhinch cutaway bog, treatment of water at this location and
pumping of treated water to the Dublin Region (overall length 124 km). A third option (Option C) is
similar to Option B other than the abstraction location is in Parteen Basin, approx 157km from the
Dublin Region.
Evaluations of these three options are summarised below.
Option B is a lower cost option than Option F2 or Option C (and also lower cost than Lough Ree
Options E and G). However, it gives rise to potential environmental concerns regarding increases in
residence times resulting from abstraction. The overall water supply scheme also lacks back up, in
the event of a major source pollution event on the Shannon or other unforeseen events.
Option F2 is preferable to Option F1 in terms of cost and suitability for raw water storage. This is due
to a shorter pipeline route and the benefits of significant silt–clay deposits under the residual peat in
Garryhinch Cutaway Bog (F2) rather than the sand–gravel deposits in Derrygreenagh Bog (F1),
making the former site more geotechnically suitable and cost effective for large-scale storage.
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The incorporation of storage (as per Option F2) into the water supply proposals provides the following
advantages:
x
Negligible residence time increases or related environmental issues would arise during low
flow periods in Lough Derg as storage provides a facility to match abstractions to flows –
higher in Winter / lower in Summer etc. Abstractions can be ceased altogether during
extended periods of low flow. Details of the abstraction regime will be established through
Hydrodynamic and Water Quality Modelling during EIA – the next stage in the project’s
development
x
Assists in climate proofing future water supplies by providing adequate storage for use
during periods of prolonged drought
x
Back-up in the event of unforeseen circumstances is provided (e.g. major pollution incident)
x
Storage provides a facility to manage peak demand in Dublin from Garryhinch rather than all
the way from the Shannon. This involves potential savings in infrastructure and operation
costs.
x
Storage facilitates relocation of substantial infrastructure footprint (eg Treatment Plant) from
the Shannon to Garryhinch
x
Storage facilitates reductions of proposed treated water storage facilities in Dublin resulting
in significant financial savings in treated water storage
Option C is environmentally sustainable and its main advantage is that there are no residence time
increase issues in Lough Derg. The principal drawback for this option is the increased length (and
associated pumping and other costs) of pipelines required to transmit water to the Dublin Region
(157 km from Parteen Basin vs 124 km from northern Lough Derg).
A small number of submissions received during SEA Phase 2 public consultation favoured Option C
(or a modified Option C with storage in Garryhinch) because abstraction for Option C is located near
Parteen Weir and at that location all stakeholders with the exception of ESB have had full beneficial
use of the Shannon’s water.
However, the main advantage of Option C (no residence time increase issues) can be achieved by
Option F2 (with the assistance of ESB operational modifications at Ardnacrusha) at considerably less
expense because of the shorter pipeline lengths involved and savings from reduced pumping energy
costs.
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8 DESALINATION / GROUNDWATER / LIFFEY BARROW OPTIONS
– EVALUATION SUMMARY
Water supply options with;
1) The Irish Sea (Option H – Desalination) as the water supply source
2) Groundwater (Option I) as the water supply source
3) Upper Liffey / Barrow Rivers (Option J) as the water supply sources
are illustrated schematically in Figure 8.1 below. These options were assessed against the following
criteria:
x
Technical
x
Environmental
x
Socio – Economic
x
Economic
The assessment results are summarised in this section.
Figure 8.1
Desalination / Groundwater / Liffey Barrow Options
OTHER SOURCES:
H-Desalination
I-Fingal / Kildare
Groundwater
J-Liffey / Barrow
MULLINGAR
Lough
Ree
Desalination Plant
H
Wells
I
Ballycoolen
ATHLONE
Termination
Point
River
Shannon
TULLAMORE
Impoundment
Ballymore Eustace
Poulaphuca Lake
Lough
Derg
J
PORTLAOISE
Athy
River
Barrow
Water Treatment Plant
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8.1
The Plan
TECHNICAL ASSESSMENTS – DESALINATION
Option H (Desalination) is a technically feasible water supply option. It would involve abstraction of
sea water from the Irish Sea in north Fingal, desalination of sea water through a desalination plant,
pumping of the treated water to Ballycoolen reservoirs via 25 km pipelines and discharge of brine
(from the treatment process) back into the Irish Sea. The technical assessments included selection of
the optimum technology for an Irish application and selection of an appropriate location for installing
the facilities.
8.1.1
Abstraction Location
A number of technically suitable locations were examined along Dublin's east coast for locating a
desalination plant (see Figure 8.2). North Fingal was identified as the optimum location because of
water quality considerations, suitability for construction of intake / outfall infrastructure, energy
availability and the relative ease of bringing treated water supplies from this location into the water
distribution system within the Dublin Region. The optimum abstraction point would be located approx
3.0 km from shore to avoid tidal effects and enhance water intake quality in terms of dissolved solids.
Disposal of brine would occur approximately 2.0km from shore to ensure satisfactory dispersal and
enable potential longterm environmental sustainability.
Figure 8.2
8.1.2
North Dublin Coastline (Potential location for siting Desalination Plant)
Selection of Optimum Desalination Technology
A number of potential desalination processes were considered as follows:
1) Thermal Evaporation Effect (MED & MSF)
2) Reverse Osmosis (RO)
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3) Electrodialysis Reversal
4) Solar Stills
Reverse Osmosis (RO) was selected as being the most appropriate desalination technology for an
Irish application principally on account of technical efficiency, cost effectiveness and relative
environmental impacts.
The key infrastructure components of the desalination plant are summarised as follows:
x
Seawater Intake facilities (3km intake)
x
Pre-treatment: disinfection/filtration (extensive because of high seawater SDI levels)
x
Reverse Osmosis Infrastructure (High Pressure Pumps & Membranes)
x
Post Treatment (mineralization)
x
Reject Stream (2km Brine Discharge Pipeline)
x
Ancillary facilities - chemical dosing, energy recovery devices etc.
Figure 8.3 below illustrates schematically the principal features of a typical reverse osmosis (RO)
desalination plant.
Figure 8.3
Typical RO Plant with Conventional Pre-treatment (for 100Ml/d)
RO With Conventional Pretreatment
210,000 m³/d
Soak
Chlorination
Energy Recovery Device
Brine
(Sludge = 10,000 m³/d)
Acid
Injection
67b 100,000 m³/d
69b
CO2
200,000 m³/d
1st Stage Filtration
Antracite
Filter Surface 1400 m²
Sea
Raw Water
Inlet & Pumping
100,000 m³/d
2nd Stage Filtration High Pressure
Pumps
Antracite + Sand
Filter Surface 800 m²
Ca(OH)2
Cl2
RO Plant
To
Air
Degasifer
8.1.3
Distribution
Treated Water Tank
Mineralisation &
Neutralisation Disinfection
Modelling of Brine Dispersion Impacts
The discharge of brine and pollutants associated with the operation of a desalination plant were
modelled using numerical modelling techniques. Modelling identified that discharge at 2km from shore
was required to ensure environmental sustainability of brine dispersion. The dispersion levels at this
distance from shore are suitably high due to the tidal regime and high current speeds in the vicinity of
the proposed discharge site.
The levels of suspended solids, iron and salt were found to be within acceptable levels outside of the
immediate vicinity of the discharge site. Sedimentation levels resulting from the sludge dispersal were
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found to be low, with very limited settlement occurring during slack water, which is subsequently resuspended and dispersed as current speeds increase as the tidal cycle progresses.
8.2
ENVIRONMENTAL / SOCIO ECONOMIC ASSESSMENTS DESALINATION
For the Desalination Option the principal potential environmental impacts identified are as follows:x
High Energy Use - CO2 production / greenhouse effects
x
Ecology of local estuarine / inshore habitats
x
Sea angling impacts
x
Sea bed disruption - construction methodologies
x
Navigation Impacts - during construction / subsequent operation
x
Disposal of Brine (effluent) from the Desalination Plant
x
Transmission Pipeline - NHA's, SPA's, SAC's, Archaeology etc.
In addition to the above potential environmental impacts, water supplies from a Desalination Plant may
be perceived by the general public as being aesthetically undesirable for drinking purposes on account
of the Irish Sea being used for disposal of potentially radioactive material, even though these issues
are fully catered for within the treatment process.
The principal environmental impacts which potentially could arise from implementation of Option H
(Desalination) are summarised in Table 8.1. These potential environmental impacts have been
assessed separately. Details are included in the “Environmental Report” which was prepared in
parallel with this report as part of the Strategic Environmental Assessment process (2007 - 2009) for
this water supply option.
Table 8.1
Environmental Impact Summary Option H (Desalination)
Issue
Environmental Impact
Energy Use
Excessive energy use resulting in potential conflict with the Irish
greenhouse gas emission targets. May be seen to go against the
principles of energy conservation.
Water Supply
As desalination is highly energy intensive and would rely heavily
on imported energy there could be some future risks in relation to
continuous security of water supply.
8.2.1
Habitats Directive Assessments
Assessments under the Habitats Directive have established that Desalination is likely to be in
compliance as it is not likely to have significant adverse impacts on designated sites.
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8.3
The Plan
ECONOMIC ASSESSMENTS DESALINATION
Capital and operating costs have been based on construction of intakes and pipelines initially for the
long-term capacity (300Mld), while the RO treatment plant and pumping facilities are designed to
match demand growth.
Capital costs are Net Present Value (NPV) costs discounted at 5% over a 25 year operational lifespan
and include:
a) Cost of RO Desalination Treatment Plant
b) Seawater Intake Pipeline
c) Brine Dispersion Pipeline
d) Transmission Pipelines and Pumping of Treated Water to Ballycoolen
e) Cost of parts and membrane renewal over 25 year operational lifespan
f)
One – off costs (preliminaries / design / management of construction / wayleaves /
land purchase etc)
Operating costs are Net Present Value costs discounted at 5% over a 25 year operational lifespan and
include:
g) Maintenance Costs
h) Energy Costs (based on energy supplies from national grid)
i)
Chemicals
j)
Sludge Disposal
k) Personnel & Overheads
Results are summarised in Table 8.2 Estimates are based on 2008 costs for labour/materials/energy.
Table 8.2
Summary of Capital / Operating / Whole Life Costs – Option H
Cost
Option H
€600m - €650m
NPV OPEX
€320m - €350m
(WLC) Whole Life Cost
(25 years)
€920m - €1,000m
WLC / Delivered Volume of
Water
€0.61/m3 -€0.67/m3
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The Plan
SUMMARY DESALINATION
Desalination of sea water is technically feasible. This technology is being increasingly used in
countries which are water stressed and which do not have alternative sustainable surface water or
groundwater sources available to them. Drinking water produced from desalination is expensive
because of high initial capital costs of intakes / outfalls/ desalination process plants and also because
of the high running costs due to the process energy required. An east coast desalination plant would
use, on average, 3 to 4 times the amount of energy required for proposed Shannon based schemes.
A desalination water supply option to produce 300Mld would cost in the order of €1bn vs €650m for
technically equivalent Shannon options with a production capability of 300/350Mld.
There are environmental issues associated with high energy use and potentially with large scale
continuous brine dispersion. There are also perceived aesthetic issues involved in relation to the
suitability of the sea as a source of drinking water and also with the taste of the finished product.
Some submissions received on the draft Plan during SEA Phase 2 public consultation proposed that
a desalination plant powered by renewable energy would be a solution which could overcome the
environmentally adverse impacts of conventional fossil fuelled desalination. There is very limited
scope for powering desalination plants with renewable sources of energy because of Energy
Regulatory Structures which apply to the operation of the single energy market in electricity. Unless a
renewable energy facility is co-located on the same site as the desalination facility, the Commission
for Energy Regulation's (CER) regulatory framework, as part of the operation of the single energy
market, requires power from the renewable source (if greater than 5 Megawatts) to be supplied
directly to the national grid. Consumers then buy power from suppliers at market prices that reflect
the mix of fuel generation types inputting energy to the grid. The proposed optimum site location for a
desalination plant for the Dublin Region is not an optimum site for co-location of a wind farm.
Use of substantial renewable energy to power the desalination plant would lower the carbon footprint
of this option but would give rise to even higher operating and overall costs. Ultimately, the national
objective of increasing and optimising renewable energy is not served by promoting high energy use
technologies where lower energy use options exist.
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The Plan
TECHNICAL ASSESSMENT GROUNDWATER
In order to assess the potential for groundwater abstractions to meet the future water supply needs of
the Dublin & Mid East Regions, a separate study was carried out by RPS in conjunction with a
leading Irish Groundwater Expert – Eugene Daly & Associates (see Appendix C).
The study examined aquifer units within 80km of Dublin’s city centre.
Due to constraining technical and non-technical factors, few groundwater supply schemes in Ireland
provide abstractions greater than 1 million gallons per day (4.5Mld). Consequently any potential
which may exist for groundwater source development as a potential strategic source of water supply
for the Dublin Region would be based on large numbers of small wellfields spread over a widely
diverse area.
Because the water resources required by the Dublin Region at 2031 are significant (§ 300Ml/d) only
relatively large groundwater resources were studied. Smaller sources, in any event, are important for
local needs, particularly for dispersed rural communities and for agricultural needs.
The total aquifer area was derived from the areas published by the River Basin Districts or was
estimated from mapped outcrop areas. A value for estimated direct recharge was calculated for each
aquifer.
The actual physical amount of groundwater that can be developed in any aquifer unit, the technically
developable resource, is normally only a fraction of the potential resource as it is highly dependent on
geological, hydro-geological and engineering considerations. The physical quantity available in the
central Leinster area was numerically estimated as part of the study.
The actual quantity of groundwater which may be available for the Dublin Region is also highly
dependent on complex environmental, economic, legal and social factors/criteria. It is practically
impossible to quantify the risks which these factors present to potential yields from multiple aquifers
over a very large area, however, assumptions can be made that actual availability will certainly be
less than the technically developable resource.
The study outlined that there may be a developable resources of approx 125Mld, technically available
from six separate major aquifer units in the Central Leinster area within an 80km radius of Dublin.
The actual quantity available would inevitably be less than this – how much less depends on complex
geological, engineering, legal, planning, environmental and economic considerations. The
environmentally sustainable resources which are likely to be available could be as low as 25Mld –
50Mld. This would be in line with the practical development of groundwater resources in the region.
Yields of 25Mld-50Mld are not of sufficient magnitude for strategic water supply purposes. The
planning figure for the Dublin Region is 300Mld (2030 – 2040). In reality these resources will be
tapped as necessary for local rural development needs, agriculture and horticulture in the relevant
areas.
The study concluded that wide scale development and use of the developable resources identified in
the study area to augment Dublin Region’s water supply would not be the optimum use of these
resources and would not satisfy the strategic needs of the region. Rather, development of these
resources for local use would be economically and environmentally more appropriate.
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The Plan
Groundwater Study Methodology
In order to assess the potential for groundwater abstractions to meet the future water supply needs of
the Dublin Region a separate study was carried out by RPS in conjunction with a leading Irish
Groundwater Consultancy – Eugene Daly & Associates.
The study examined aquifer units within 80km of Dublin’s city centre (the study area) - see Figure 8.4.
Because of the significant volumes of water required by the Dublin Region, the study focused on
aquifer units which are at least 10sq.km in area and which are classified by the Geological Survey of
Ireland (GSI) as regionally or locally important. The groundwater bodies identified by the River Basin
District Projects were used as a basis for the study.
Due to constraining technical and non-technical factors, few groundwater supply schemes in Ireland
provide abstractions greater than 1 million gallons per day (4.5Ml/d). Resource development has been
on a relatively small scale. Individual groundwater based water supply schemes are generally less
than 1Ml/d, with a small number up to 2.5Ml/d and only occasionally up to 5Ml/d. Consequently any
potential which may exist for groundwater source development as a potential strategic source of water
supply for the Dublin Region would be based on large numbers of small wellfields spread over a
widely diverse area. The quantitative risks of such an approach are not ideal for the strategic water
volumes required.
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Figure 8.4
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Groundwater Study Area (80km radius from Dublin)
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8.5.2
The Plan
Methodology for Deriving Potential Yields from Groundwater Bodies
A scoping exercise was undertaken for each groundwater body to determine which ones were likely to
obtain sufficient yields to provide or supplement water supplies for the Dublin Region. Groundwater
bodies that are greater than 10km2 in plan and not classified as poorly productive by the RBD project
were considered for the study. Groundwater bodies adjacent to each other and with similar geology
were combined and considered as a single aquifer unit.
The strategic water resources required by the Dublin Region at 2030 – 2040 are significant (§
300Ml/d) and therefore only relatively large groundwater resources are of relevance to this long-term
water supply study.
The total aquifer area was derived from the areas published by the River Basin Districts or was
estimated from mapped outcrop areas. A value for estimated direct recharge was calculated for each
aquifer.
Once the estimated recharge or throughput was calculated it was necessary to approximate the
current (and future) resources that are required by other beneficial uses of the recharge such as for
the maintenance of baseflow (including springflow) in rivers and streams crossing the outcrop area,
wetlands in hydraulic continuity, high yielding wells tapping the particular aquifer unit and appropriate
allowances for current and future private groundwater developments.
Once an estimate of the volume required for beneficial usage was made, a value for the resource
potentially available for development in each aquifer unit was generated (by subtraction). This value is
not the quantity that can actually be developed from wellfields. The actual amount (developable
resource) is only a fraction of the potential resource and is dependent on many technical factors which
are discussed in the Groundwater Report, Appendix C.
8.5.3
Constraints
Due to the often complex nature of the geology in the area surrounding Dublin City, it can be difficult to
predict well yields.
The following technical constraints apply when developing groundwater resources for public supply
requirements:
x
The number of potential targets and wellfield areas in any one aquifer is limited to high
transmissivity or permeability zones, which are areas where the groundwater flow is
concentrated. In Irish bedrock aquifers these zones are limited and are generally associated
with faults and/or river valleys, some karst features or other natural depressions. It is only in
such areas that the strata are sufficiently productive, efficient wells can be constructed and
wellfields are economically viable. Resources hydraulically disconnected from such areas
cannot be developed efficiently at the scale required.
x
Groundwater flow is often greatest in areas of weak geological strata. Sometimes the ground
conditions prevent the completion of stable large capacity wells. Suitable open (non urban)
land must be available for construction of wellfields, control rooms/pumping stations and the
construction of pipelines.
x
The existing groundwater quality must be satisfactory and upgradient land use must be
compatible with the provision of long-term potable water supply.
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The Plan
Nearby groundwater abstractors, streamflows, wetland habitats and other hydrogeological
features must not be significantly impacted.
In addition to technical constraints other considerations apply:
x
There must be sufficient resources available in individual areas to make them economically
feasible to develop and to pipe/convey water from them to points of distribution/use.
x
Legal considerations present considerable risk since there is an uncertain legal framework for
the development of groundwater resources, however compensation for use of groundwater
resources must be considered.
x
Compensation for Access to Lands for works undertaken on private lands must be considered.
x
Planning requirements; for abstractions in excess of 5 Ml/d, an EIS is required.
x
Security of supply; supply may be compromised at any point by another groundwater supply
intercepting its zone of contribution which presents a high risk to potential yields.
x
Protection of Zone of Contribution of wellfields must be considered in order to protect the
quantity and quality of sources.
The actual physical amount of groundwater that can be developed in any aquifer unit, the technically
developable resource, is normally only a fraction of the potential resource as it is highly dependent on
geological, hydro-geological and engineering considerations. The physical quantity available in the
central Leinster area was numerically estimated as part of the study.
Owing to the uncertainty and difficulty in developing most Irish bedrock aquifers the study exercised
caution in assuming groundwater potential without detailed investigations. In order to cover some of
these uncertainties a multiplier/fraction of 25% in the case of minor or locally important aquifers and
50% in the case of major or regionally important aquifers was used to cover hydrogeological and
general technical risk.
The actual quantity of groundwater which may be available for the Dublin Region is also highly
dependent on complex environmental, economic, legal and social factors/criteria. It is practically
impossible to quantify the risks which these factors present to potential yields from multiple aquifers
over a very large area, however, assumptions can be made that actual availability will certainly be less
than the technically developable resource.
8.5.4
Summary of Groundwater Study
The study area (80km radius from Dublin) covers an area of over 20,000km2 and includes almost the
entire Eastern RBD and parts of two others (South Eastern and Neagh Bann RBD). The region covers
a number of river catchments and different topographic settings.
The geology of the area includes a variety of different rock types and Quaternary (subsoil) deposits.
Owing to the low to moderate permeability of the strata in this area the groundwater resources are
generally low relative to other areas of the country. The available resources within 25km of the centre
of Dublin are particularly low.
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Good yields (relatively speaking), have historically been obtained from wells tapping the Loughshinny
Formation at the Bog of the Ring. The rate of abstraction from the Bog of the Ring scheme ranges
from 3Mld to 4 Mld. However, groundwater monitoring at the Bog of the Ring has shown that “the
regional water table is in long term decline and has not reached a steady state at the end of 2005. The
ERBD reports that since the summer of 2003, the wellfield has been pumping about 3.5 Mld and
available hydrographs suggest that a gradual lowering of groundwater levels is taking place within the
wellfield. Nevertheless, the Loughshinny Formation to the west of the Lusk-Bog of the Ring
groundwater body has been considered as one of the developable groundwater bodies in the Greater
Dublin Area, with an estimated resource of approx 10Mld.
The deposits beyond the 25km distance from Dublin are more extensive. There has been widespread
development of groundwater in the area via low yielding wells outside the main urban centres. There
has also been a certain amount of development via high yielding wells and many of the local
authorities in the area have plans for further development in the future. These proposed developments
have been factored into demand projections.
In recent years the location of areas suitable for groundwater development, even aside from proving the
presence of adequate resources has become more difficult owing to the:
x
Increased level of development;
x
Deterioration in groundwater quality in some areas, and,
x
Problems with gaining access to lands for investigation.
Owing to the variety of physical, chemical, environmental and engineering/economic constraints as
outlined above, the proportion of aquifer throughput that may be available for development could be as
low as 10% to 20%.
The study outlined that there may be significant groundwater resources, i.e., about 125Mld, technically
available in the six aquifer units in the Central Leinster area. The estimated total technically available
resources only account for about a third of the Dublin Region’s required demand (at 2031). The actual
quantity available would inevitably be less than this – how much less depends on complex legal,
planning, engineering, environmental and economic considerations. The environmentally sustainable
resources which are likely to be available could be as low as 25Mld.
The question of whether or not the groundwater (identified by the study) should be used for the Dublin
Region’s future water supply, and whether it would be the most appropriate use of these resources
was also addressed in the groundwater report
8.6
ENVIRONMENTAL ASSESSMENT OF GROUNDWATER
This option was technically incapable of meeting the requirements of the study and therefore was not
assessed in the Environmental Report.
8.7
ECONOMIC ASSESSMENT GROUNDWATER
Based on recent experience with Irish groundwater source developments the principal costs are
summarised as follows:
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8.8
The Plan
x
Exploration costs are in the order of €100,000 / Mld
x
Development and connection to distribution systems are in the order of €3m / Mld
SUMMARY GROUNDWATER
In order to assess the potential for groundwater abstractions to meet the future water supply needs of
the Dublin Region, a separate study was carried out by RPS in conjunction with a leading Irish
Groundwater Expert – Eugene Daly & Associates (see Volume 2 Appendices).
The study examined aquifer units within 80km of Dublin’s city centre.
Due to constraining technical and non-technical factors, few groundwater supply schemes in Ireland
provide abstractions greater than 1 million gallons per day (4.5Mld). Consequently any potential
which may exist for groundwater source development as a potential strategic source of water supply
for the Dublin Region would be based on large numbers of small wellfields spread over a widely
diverse area.
Because the water resources required by the Dublin Region (2030 – 2040) are significant (§ 300Ml/d)
,only relatively large groundwater resources were studied. Smaller sources, in any event, are
important for local needs, particularly for dispersed rural communities and for agricultural needs.
The total aquifer area was derived from the areas published by the River Basin Districts or was
estimated from mapped outcrop areas. A value for estimated direct recharge was calculated for each
aquifer.
The actual physical amount of groundwater that can be developed in any aquifer unit, the technically
developable resource, is normally only a fraction of the potential resource as it is highly dependent on
geological, hydro-geological and engineering considerations. The physical quantity available in the
central Leinster area was numerically estimated as part of the study.
The actual quantity of groundwater which may be available for the Dublin Region is also highly
dependent on complex environmental, economic, legal and social factors/criteria. It is practically
impossible to quantify the risks which these factors present to potential yields from multiple aquifers
over a very large area, however, assumptions can be made that actual availability will certainly be
less than the technically developable resource.
The study outlined that there may be a developable resources of approx 125Mld, technically available
from six separate major aquifer units in the Central Leinster area within an 80km radius of Dublin.
The actual quantity available would inevitably be less than this – how much less depends on complex
geological, engineering, legal, planning, environmental and economic considerations. The
environmentally sustainable resources which are likely to be available could be as low as 25Mld –
50Mld. This would be in line with the practical development of groundwater resources in the region.
Yields of 25Mld-50Mld are not of sufficient magnitude for strategic water supply purposes. The
planning figure for the Dublin Region is 300Mld (2030 – 2040). In reality these resources will be
tapped as necessary for local rural development needs, agriculture and horticulture in the relevant
areas.
The study concluded that wide scale development and use of the developable resources identified in
the study area to augment Dublin Region’s water supply would not be the optimum use of these
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resources and would not satisfy the strategic needs of the region. Rather, development of these
resources for local use would be economically and environmentally more appropriate.
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8.9
The Plan
TECHNICAL SSSESSMENT LIFFEY BARROW
This Option (Option J) involves the “conjunctive use” of the River Barrow with the Upper Liffey.
Approx 50% of the Dublin Region’s water supply comes from Poulaphuca Lake on the Upper Liffey via
Ballymore Eustace (BME) Water Treatment Plant (WTP). The Liffey-Barrow “conjunctive use” option
envisages abstractions of water from the Barrow when sustainable quantities may be available and
combining these abstractions with variable abstractions from Poulaphuca with a view to increasing the
overall supply to Ballymore Eustace Water Treatment Plant over and above what is sustainably
available from Poulaphuca on its own. Figure 8.5 and Figure 8.6 illustrate the operational
methodology and rationale of this option. Figure 8.7 and Figure 8.8 show aerial photography of
Poulaphuca reservoir and the River Barrow.
Figure 8.5
Schematic of Option J Operation
Poulaphuca Lake
Enhanced Abstraction
River Barrow
Pumped Main
Gravity Feed
Levitstown
Existing
Existing
Water
Water
Treatment
Treatment
Plant
Plant
Proposed
Proposed
Water
Water
Treatment
Treatment
Plant
Plant
Ballymore Eustace
Water Treatment Plant
New Trunk
Main
Existing Trunk Mains
(max. 320 MLD)
Saggart
Reservoir
Figure 8.6
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Figure 8.7
Poulaphuca Reservoir
Figure 8.8
River Barrow
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8.9.1
The Plan
Water Availability from the Barrow
The flow duration curves for the Barrow River illustrate that it has some technical potential to yield
varying amounts of water in the January- March/April and November-December periods. Abstractions
of water in May/June and October would be much more limited and may not be achievable in future
climate change flow regimes. No water would be available from July to September.
8.9.2
Water Availability from the Liffey
The Liffey Catchment can be divided into three reaches: the Upper Liffey Catchment from the source
to Poulaphuca/Golden Falls, the Middle or Intermediate Liffey Catchment from Golden Falls to Leixlip,
and the Lower Liffey Catchment from Leixlip to Dublin (Figure 8.9).
The existing and proposed levels of abstraction from the Liffey for Ballymore Eustace WTP and Leixlip
WTP (as of 2004) are shown on Figure 8.9 as well as the minimum statutory compensation flow
requirements at Golden Falls and Leixlip.
Figure 8.9
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8.9.3
The Plan
Water Availability - Liffey Barrow Conjunctive Use
If it were possible to predict in advance the amount by which the stored water in Poulaphuca would
prove insufficient to sustain an abstraction regime in any given year it would be very beneficial in terms
of water resources to have the facility to import water from another source (Barrow) even at a
significant cost.
Since it is not possible to predict in this manner, the conjunctive use strategy has to operate on the
basis of maintaining water levels in Poulaphuca Reservoir at near full for the Winter/Spring duration in
order to ensure maximum yield when the full conjunctive input to BME is being met from Poulaphuca
alone (in Summer/Autumn).
Operating Poulaphuca Reservoir in this manner during Winter/Spring would result in:
a) Loss of some flood management capability
b) Potential Reductions in Dam Safety margins
c) Frequent involuntary spillages of water to the middle/lower Liffey which otherwise could
have been captured for water supply use thereby avoiding the need to extract from the
Barrow
In addition to the difficulties at Poulaphuca, successfully achieving planning consent for irregular and
inefficient abstractions from the Barrow would be unlikely.
Notwithstanding the above serious deficiencies in this proposal a number of potential conjunctive use
scenarios were modelled (Table 8.3) to assess the technical availability of water with reference in
particular to impacts on Poulaphuca Reservoir lake levels.
Poulaphuca Reservoir operates between 186.3m OD (Poolbeg Datum) and 179.9m OD. Any modelled
abstraction regime which resulted in Poulaphuca Lake levels going below 179.90m OD were assessed
as technically unavailable. In reality, lake levels in Poulaphuca have rarely been drawn down below
183.00m OD in over twenty years and this level would now be widely regarded as the longterm
environmentally sustainable level.
Scenario 2
Scenario 1
Table 8.3
Barrow to
BME
(Mld)
Poulaphuca
to BME
(Mld)
Conjunctive
Yield
(Mld)
Barrow to
BME
(Mld)
Poulaphuca
to BME
(Mld)
Conjunctive
Yield
(Mld)
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Conjunctive Use of Liffey (Poulaphuca) and Barrow
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sept
Oct
Nov
Dec
80
80
80
80
80
80
-
-
-
80
80
80
280
280
280
280
280
280
360
360
360
280
280
280
360
360
360
360
360
360
360
360
360
360
360
360
120
120
120
120
120
-
-
-
-
120
120
120
280
280
280
280
280
400
400
400
400
280
280
280
400
400
400
400
400
400
400
400
400
400
400
400
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8.9.4
The Plan
Hydrological Modelling
A computerised model, which simulates the performance of the Liffey catchment was developed by
Tobin Consultant Engineers as part of a study on behalf of Fingal County Council. The Fingal study
examined the feasibility of expanding the capacity of the Leixlip Water Treatment Plant to abstract and
treat up to 225Ml/d from the Liffey at Leixlip.
The modelling involved specifying the abstractions at Poulaphuca (for BME) and at Leixlip and the
required compensation flows downstream at Golden Falls and Leixlip Dams.
The model examined the historical record (of lake levels in Poulaphuca) and replicated it in each year
of record as if the proposed abstractions had been in place instead of actual rates of water abstraction
at that time.
The model assumed power generation is secondary to water supply provision. The model output of
particular interest to this ‘conjunctive use’ option evaluation was the resultant lake level in Poulaphuca
for variable conjunctive abstractions.
8.9.5
Modelling Results Summary
Scenario No 1
Abstracting 80 Mld from the Barrow in the months from October to June each year, combined with a
restrained drawoff from Poulaphuca of 280 Mld over the same period, results in a combined
conjunctive water availability of 360 Mld, which is 42 Mld over the planned use at present.
Abstractions of this magnitude from the Barrow in May/June and October are unlikely to be achievable
on a 100% basis in this scenario and this situation may be further impacted by climate change.
Nevertheless, assuming Barrow abstractions are achievable at the modelled level, the modelling
results indicates that the additional 40Mld would be available for all of the period from a technically
achievable perspective and in an environmentally achievable manner for over 80% of the period.
Given the uncertainties, the likely longterm environmentally sustainable water availability range from
this modelled scenario is 20Mld – 40Mld.
Scenario No 2
A larger abstraction of 120 Mld from the Barrow in the months from October to May each year, would
accompany a similarly restrained drawoff from Poulaphuca of 280 Mld over the same period, in an
increased combined demand of 400 Mld which is 80Mld in excess of current planned abstractions.
Abstractions of this magnitude from the Barrow in May and October are unlikely to be achievable on a
100% basis in this scenario and this situation may be further impacted by climate change.
Nevertheless, assuming Barrow abstractions are achievable at the modelled level, the modelling
results indicates that the additional 80Mld would be available for 90% of the period from a technically
achievable perspective and in an environmentally sustainable manner for over 60% of the period.
Given the uncertainties, it is unlikely that this scenario would successfully achieve the necessary
planning consent to provide continuous additional water availability of 80Mld.
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8.10
The Plan
ENVIRONMENTAL ASSESSMENT LIFFEY BARROW
This option was technically incapable of meeting the requirements of the study and therefore was not
assessed in the Environmental Report.
8.11
SUMMARY LIFFEY BARROW
The Liffey-Barrow ‘conjunctive use’ option would involve abstractions of water from the River Barrow
when sustainable quantities may be available (eg Winter & Spring) and combining these abstractions
with variable abstractions from Poulaphuca (less in Winter / more in Summer), with a view to
increasing the overall supply to Ballymore Eustace Water Treatment Plant over and above what is
sustainably available from Poulaphuca on its own. The ‘conjunctive use’ option would require
Poulaphuca reservoir being operated and maintained in a ‘near-full’ condition from approximately
November / December through to April / May.
Modelling and analysis of the proposed ‘conjunctive use’ option illustrated that additional water
availability greater than 20Mld is unlikely to be achievable in an environmentally sustainable manner.
In order to operate this scheme successfully it would be necessary to maintain Poulaphuca reservoir
in a near-full condition during winter and spring. Maintaining Poulaphuca reservoir in a near-full
condition from approximately November through to May would result in a reduced capability to
manage floods and could lead to reduced dam safety margins. Operating the reservoir in a near-full
condition could also result in frequent involuntary spillages of water to the middle and lower Liffey
catchments because Poulaphuca’s storage capacity would be at its practical limit. This would result in
water being pumped from the Barrow to effectively replace water which could have been captured in
Poulaphuca but which had to be ‘spilled’ to the middle and lower Liffey. This would be both inefficient
and costly.
Abstractions from the Barrow and Liffey in this manner would be highly unlikely to achieve the
necessary licences to enable their implementation. Even if planning consent was achievable, the
maximum increased water availability range would be 20Mld-40Mld. This level of additional supply is
totally inadequate for the Dublin Region’s planned requirement of 300Mld (2030 – 2040).
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9 EVALUATION OF WATER SUPPLY OPTIONS
9.1
METHODOLOGY FOR WATER SUPPLY OPTION EVALUATION
9.1.1
Sustainable Development
In total, ten water supply options were evaluated for their potential to supply the Dublin Region with its
long-term water supply needs in order to augment existing supply sources which will have reached
their sustainable, agreed, licensed supply capacity by approx 2016. Each option was assessed for its
potential to comply with the principles of sustainable development.
Sustainable development is broadly defined as the development of resources which aim to meet
human needs while preserving the environment, so that these needs can be met not only in the
present, but in the indefinite future i.e. development which "meets the needs of the present without
compromising the ability of future generations to meet their own needs."
In keeping with the principles of sustainable development, the evaluation of water supply options was
undertaken against the background that the recommended option(s) “has to be viable and sustainable
and cannot be to the detriment of any other area”.
Sustainability assessments involved technical, environmental, economic and socio-economic
assessments in order to evaluate option compliance with sustainability criteria (see section 9.1.4 for
further detail).
9.1.2
Strategic Environmental Assessment (SEA)
Following sustainability assessments, the options for meeting Dublin’s longterm water supply needs
were subjected to Strategic Environmental Assessment as required by the Strategic Environmental
Assessment (SEA) Directive (2001/42/EEC) which was transposed into national legislation in Ireland
in 2004 through SI 435/2004 and SI 436/2004. This legislation requires that certain Plans and
Programmes prepared by statutory bodies, which are likely to have a significant impact on the
environment, be subject to the SEA process. Article 3(2) of the SEA Directive makes SEA mandatory
for plans and programmes:
a) which are prepared for agriculture, forestry, fisheries, energy, industry, transport, waste
management, water management, telecommunications, tourism, town and county
planning or land use and which set the framework for future development consent for
projects listed in Annexes I or II of the Environmental Impact Assessment (EIA) Directive
(85/337/EEC); or
b) which, in view of the likely effect on sites, have been determined to require assessment
pursuant to Article 6 or 7 of the Habitats Directive (92/43/EEC).
The first phase of Strategic Environmental Assessment (SEA Ph1) commenced in 2006 in relation to
three water supply options (Shannon – Lough Ree, Desalination and Liffey–Barrow). Formal public
consultation took place during June / July 2006. Feedback from the SEA Ph1 public consultation
process resulted in a wider range of water supply options being included in follow - up studies during
2007/8. The second phase of Strategic Environmental Assessment (SEA Ph2) in relation to the
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expanded range of water supply options commenced in early 2008 and formal public consultation took
place from November 2008 to February 2009.
Substantial feedback was received during the SEA PH2 public consultation. This feedback has been
analysed and taken into account during the preparation of the Plan. A comprehensive report on all
issues raised in relation to the (Draft) Plan during SEA public consultation is available in the Public
Consultation Report www.watersupplyproject-dublinregion.ie / publicconsultationreport.
9.1.3
Draft Plan (Technical Report) SEA Environmental Report / Habitats Directive
Report
The SEA legislative process required the production of an Environmental Report in parallel with the
preparation of the Draft Plan. The SEA legislation ensures that environmental considerations are taken
into account during preparation of the Plan and prior to its adoption. It also guarantees that
stakeholder and public opinions are accounted for.
The Draft Plan outlined the projected water supply requirements from a new source and technical /
economic data in respect of the various water supply options which were evaluated for meeting the
supply requirements in a long-term sustainable manner.
The SEA Environmental Report considered each option and all options were subjected to an
“Appropriate Assessment” of Natura 2000 sites in accordance with the requirements of the Habitats
Directive (92/43/EEC).
The SEA process ensures that potential environmental impacts (both positive and negative)
associated with the supply of a new major water source to the Dublin Region Water Supply Area
(DRWSA) are given due consideration in the preparation of the Plan. It is a stated objective of the Plan
to minimise the environmental, social and economic impacts of a new water supply source and the
SEA process contributes to achieving this objective.
The Habitats Directive Assessment (HDA) report undertook a phased process in ascertaining if there
are internationally important sites whose integrity could be significantly adversely affected by the
implementation of the (draft) Plan. This assessment identified a number of options which had the
potential to constitute an unacceptable risk to designated sites and/or protected species.
Statutory consultation on the (draft) Plan, the SEA Environmental Report and the HDA Report took
place, from 24th November 2008 to 27th February 2009, in accordance with Article 6 of the SEA
Directive.
9.1.4
Evaluation Criteria / Assessment
As outlined in 9.1.1 above, in order to assess each water supply option’s compliance with the
requirements for sustainable development, the options were assessed and evaluated in accordance
with the following criteria:
x
Technical
-
Yield of Source / Modelled Abstraction Impacts / Flows / Levels / Climate Change
-
Infrastructure (Abstraction / Pumping / Treatment / Storage / Transmission etc)
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x
x
x
The Plan
Environmental
-
SEA Environmental Report – Aquatic / Terrestrial Ecology / Archaeology / Population
& human Health and other SEA environment issues
-
Habitats Directive Assessment / Designated Sites – SPA / SAC / NHA / protected
species
-
Water Framework Directive / Water Quality Objectives
Economic
-
NPV of Capital & Operating Costs
-
Whole Life Costs / Cost of Water Delivered
Socio – Economic
-
Navigation / Tourism / Angling / Fisheries /Agriculture / Local Economy etc
-
Availability of Water for Local Use / Flooding
Detailed evaluations of the options are contained in the Draft Plan, the SEA Environmental Report and
the Habitats Directive Assessment Report. Additional Technical Reports were also prepared in order
to ensure appropriate evaluation of the options in keeping with the requirements of the SEA process.
These reports include: Desalination Report, Groundwater Report and Shannon Modelling Report. All
reports and relevant associated data (FAQs etc) are available on the dedicated project website
www.watersupplyproject-dublinregion.ie.
Further to this evaluation a lengthy public consultation process was carried out on all three reports. A
large number of submissions were received. Also during this period presentations were made to
various stakeholder groups which included question and answer type sessions. Recommendations
from the public consultation process have been considered and where appropriate incorporated into
this Plan. A summary table of all feedback received has been developed and this is included the
Public Consultation Report www.watersupplyproject-dublinregion.ie / publicconsultationreport.
9.1.5
Water Framework Directive
Subsequent to the public consultation process, the Draft River Basin Management Plans (RBMPs)
were issued. The final RBMPs for the Eastern River Basin District (ERBD) and the Shannon
International River Basin District (SIRBD) have been reviewed. This was to ensure that the WSP-DR
Plan takes cognisance of these and that this Plan is not conflicting with the objectives of the RBMPs.
Details from this assessment are outlined in Section 4.
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9.2
The Plan
SELECTION OF THE RECOMMENDED PREFERRED OPTION
Ranking of water supply options which are capable of meeting the Dublin Region’s long-term water
supply requirements in a sustainable manner was carried out by:
x
Analysis of Feedback from Public Consultation
and
x
Evaluation of Options for compliance with sustainability criteria (Sections 6,7 & 8)
Section 10 contains option ranking details and a recommended preferred option for progressing to the
next stage – the formal planning process involving the independent Planning Authority – An Bord
Pleanala.
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10 RANKING OF OPTIONS & SELECTION OF RECOMMENDED
PREFERRED OPTION
The feedback from public consultation and the sustainability evaluation of options (Sections 6, 7 and
8) involved technical, environmental, socio economic and economic assessments. Each Option was
assessed against each of the criteria with the exception of Option I (Groundwater) and Option J (Liffey
Barrow) which were identified by the technical assessments as having capacity limitations which made
these options unsuitable for further consideration as potential new source options. The content of the
assessment criteria is set out in Section 10.1.
10.1 ASSESSMENT CRITERIA
1) Technical
a) Source Options (water body & location)
Evaluations were based on the relative capability of the various source options to provide abstractions
of approx 300/350Mld in a sustainable manner. The evaluations take account of the hydrological
modelling results including the modifications to control structures (weirs and sluices) which may be
necessary to ensure continuous provision of 350Mld. Difficulties which may arise in achieving
necessary control structure modifications are assessed. Scaling back abstractions during dry periods
and / or the provision of storage are factored into the “relative evaluation” process. Quality of source
water is also considered.
b) Infrastructure (pipelines, pumping, water treatment, storage)
Evaluations were based on the relative reliability, resilience, durability, flexibility and technical
complexity of the options. Options involving storage are more resilient and flexible than direct supply
options. Options involving complex water treatment or long pipelines are less favourable than options
involving less infrastructure and simpler water treatment processes. Suitability of pipeline routes and
treatment plant sites are factored into the “relative evaluation” process.
2) Environmental
a) Strategic Environmental Assessment (SEA) ( S.I. 436 of 2004)
SEA legislation contains a list of environmental issue areas against which the various water supply
options must be evaluated for impacts. Evaluations were based on impacts against the following
criteria; Biodiversity, Flora and Fauna, Fisheries, Water, Air and Climatic Factors, Soils and
Hydrogeology, Population and Human Health, Cultural Heritage, Landscape and Land use, Material
Assets, and the interaction between these receptors.
b) Habitats Directive Assessment (HDA) (S.I. 94 of 1997)
Potential impacts of option “infrastructure and operation” on European Designated Sites are evaluated.
Evaluations of impacts were assessed as (a) likely to have significant effects on the integrity of
European Sites or (b) no significant effect on the integrity of European Sites or (c) inconclusiveapplying the precautionary principle as the existing data does not provide enough certainty to
determine if there will be no risk to the integrity of a European designated site.
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3) Economic (Capital Cost, Operational Cost , Whole Life Cost , Cost of Water Delivered)
Evaluations were based on straightforward relative cost assessments over a 25 year operating period.
Net Present Values (NPV) are calculated using a 5% discount rate. Estimates are based on 2008
costs for labour / materials / energy etc. Relative economic cost of options has to be considered in
conjunction with each options performance under the other sustainability criteria i.e. technical,
environmental and socio economic.
4) Socio Economic (Impacts of Options on Navigation, Tourism, Agriculture, Angling, Local
Economy etc)
For Shannon options, the ability to abstract water within the operating range of lake levels specified in
ESB Regulations is a key consideration in the assessment of potential impacts on tourism, local
economy etc. Capability of options to provide treated water to local authorities between the Shannon
and Dublin are considered. Capability of options to ensure adequate availability of water for longterm
local use is considered. Potential enhancements to the local environment including potential for better
water quality through increased focus on quality issues and environmental rehabilitation of cutaway
bogs (storage options) are factored into the “relative evaluation” process.
Socio economic benefits in having adequate water availability for the Dublin Region apply equally to all
technically feasible options.
10.2
EVALUATION SUMMARY
In order to summarise the results of studies, consultations and evaluations, each water supply option
was allocated a ‘relative rating’ against each of the sustainability evaluation criteria. Relative or
comparative ratings are represented with symbols and range from major negative (--) to major
positive (++) as outlined in Table 10.1 below. Ratings for the Habitat’s Directive Assessments are
outlined in Table 10.2.
The results of comparative evaluations for each option against each of the sustainability criteria are
presented in Table 10.3 to Table 10.8. A commentary, summarising the rationale for the rating of
each option against each of the evaluation criteria is also provided. An evaluation summary, which
ranks all of the options against all of the sustainability criteria, is presented in Table 10.9.
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Table 10.1
The Plan
Sustainability & Environmental Evaluation Rating Chart
Rating Parameter
Rating
Symbol
Major Negative
--
Minor Negative
-
Neutral
~
Minor Positive
+
Major Positive
++
Table 10.2
Habitats Directive Assessment (HDA) Rating
Rating Parameter
Likely to Affect Designated Sites (SAC /
SPA / NHA )
Rating
Symbol
--
Inconclusive
-
No significant Effect on Designated Sites
~
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Table 10.3
Option
Technical Assessment (Source)
Description
Option F
F1 & F2
Lough Derg + Storage
(Bog)
Option C
Parteen Basin
Option B
Lough Derg
Option E
Lough Ree + Storage
(Bog)
Option G
Lough Ree +
Impoundment
Option D
Lough Ree (Phase 1) /
Lough Derg (Phase 2)
Option A
Lough Ree
Option H
Desalination
Option I
Groundwater
Option J
Liffey - Barrow
Conjunctive Use
MDW0158RP0091
The Plan
Technical Assessment
Capability of Source for 350Ml/d Continuous Abstraction
With ESB co-operation (Ardnacrusha), Lough Derg on its own (as per Option B), does not require
storage back-up to maintain water levels. However, strategic storage (2 months) optimises peak
management & has lower energy footprint than Option B. Facilitates relocation of infrastructure
footprint (eg Water Treatment) and offsets/ eliminates any potential residence time impacts.
Storage provides resilience for (say) major pipeline breaks or pollution incident in Lough Derg
requiring pumping cessation.
350Ml/d is 100% available in dry or climate change periods. No change in lake levels. No increase
in residence times. Requires agreement with ESB to modify power generation activities due to 1% 2% reduction in average water flows. Without storage (as per Option F) there is no back-up /
resilience for major pipeline breaks or pollution incidents.
350Ml/d is 100% available in dry or climate change periods. No change in lake levels. Requires
agreement with ESB to modify generation activities due to 1% - 2% reduction in average water flow
availability resulting from abstraction. Abstraction related flow reductions may marginally increase
residence times in dry periods. Without storage (as per Option F) there is no back-up / resilience for
major pipeline breaks or pollution incidents.
Increased abstractions of up to 500Ml/d from Lough Ree between Nov and June and minimum
abstractions of 50Ml/d July to October can be achieved in compliance with ESB Regulations.
Abstractions may require minor modifications to sluice operations, particularly in dry periods. A
minimum of 4 months storage is required in order to ensure equivalent of 350Ml/d over 12 months.
Increased abstractions of up to 420Ml/d from Lough Ree between November and July and
minimum abstractions of 60Ml/d July to October can be achieved in compliance with ESB
Regulations with minor modification to sluice operation. No supplies en route. Minimum 4 months
average supply requires to be impounded in order to ensure equivalent of 300Ml/d over 12 months.
Phase 1 requirement of 250Ml/d requires modification to operation of sluices which may marginally
increase flooding risk as per Option A. Phase 2 requirement of 100Ml/d is 100% available. Option D
requires ESB agreement as per Options B and C.
100% availability of 350Ml/d would require change in sluice operations at Athlone in order to
comply with ESB Regulation levels. Change in operation of sluices would require widespread
stakeholder agreement. Change could increase risk of flooding - Lough Ree & Callows. Abstraction
increases durations of minimum flow periods.
Technically feasible option which is being implemented increasingly in water stressed areas of the
world. No limitation on abstraction quantity of sea water but water quality requires expensive
treatment with high energy requirements.
Groundwater for public supply (25Ml/d-50Ml/d) is not available in sufficiently sustainable quantities
to cover long-term needs.
Sustainable availability of water from this option (20Ml/d - 40Ml/d) is too low to be considered as a
strategic supply source.
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F02
Water Supply Project – Dublin Region
Table 10.4
The Plan
Technical Assessment (Infrastructure)
Technical Assessment
Infrastructure (Pipeline / Pumping / Water Treatment / Storage)
Draft
Evaluation
Option
Description
Option E
Lough Ree + Storage (Bog)
Option A
Lough Ree
Option F
F1 & F2
Lough Derg + Storage (Bog)
Option B
Lough Derg
Option C
Parteen Basin
Option D
Lough Ree (Phase 1) /
Lough Derg (Phase 2)
Option H
Desalination
Option G
Lough Ree + Impoundment
Option I
Groundwater
Groundwater for public supply (25Ml/d-50Ml/d) is not available in sufficiently sustainable quantities
to cover long-term needs.
N/A
Option J
Liffey - Barrow Conjunctive
Use
Sustainable availability of water from this option (20Ml/d - 40Ml/d) is too low to be considered as a
strategic supply source.
N/A
MDW0158RP0091
Pipeline route is shortest route Shannon to Dublin (104km). Pipeline route (as per Option A) is
satisfactory. Relocation of water treatment footprint to bog location satisfactory. Requires 4 months
storage (large area required). Storage provides resilience and operational flexibility.
Pipeline route is shortest route Shannon to Dublin (104km). Route avoids
SPAs/SACs/NHAs/archaeology etc. Satisfactory hydraulic profile for pumping requirements.
Suitable sites are available for abstraction and water treatment.
Pipeline routes from Shannon to Dublin are satisfactory (F1 -127km, F2 - 122km). Relocation of
water treatment footprint to bog location(s) satisfactory. Strategic storage - 2 months - satisfactory
location. Storage provides resilience and operational flexibility.
Pipeline route from Shannon to Dublin is satisfactory (122km). Route avoids
SPAs/SACs/NHAs/archaeology etc. Satisfactory hydraulic profile for pumping requirements.
Suitable sites are available for abstraction and water treatment.
Pipeline route from Shannon to Dublin is long (158km). Abstraction location requires ESB approval
re embankments. Satisfactory technical profile for pumping requirements. Suitable sites are
available for abstraction and water treatment.
Combined pipeline routes are long (171km) but satisfactory route and hydraulic profile are
available. Requires 2 pumping stations and 2 treatment plants (large infrastructural footprint).
Suitable sites are available for abstraction and treatment plant.
Limited availability of suitable sites for desalination plant (10 - 15 hectares). Complex (expensive)
marine works for intake and brine dispersion outfall infrastructure. Treatment plant is highly
dependent on consistent water quality. Treatment Plant requires regular membrane replacement
and is highly energy dependent. Pipeline route is short (25km) but is in semi-urban location.
Pipeline route from Shannon to impoundment 113km satisfactory. Suitable sites are available for
abstraction and pumping. No supplies are available to Local Authorities en route. Impoundment
locations complex (technically) and energy inefficient.
110
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Water Supply Project – Dublin Region
Table 10.5
Option
The Plan
Environmental Assessment (SEA)
Description
Option F
F1 & F2
Lough Derg + Storage (Bog)
Option C
Parteen Basin
Option E
Lough Ree + Storage (Bog)
Option B
Lough Derg
Option D
Lough Ree (Phase 1) /
Lough Derg (Phase 2)
Option G
Lough Ree + Impoundment
Option H
Desalination
Option A
Lough Ree
Option I
Groundwater
Option J
Liffey - Barrow Conjunctive
Use
MDW0158RP0091
Strategic Environmental Assessment
(SI No 435 & 436 of 2004)
Direct impact on SAC and SPA. No significant issues identified relating to low flows. Potential for
increased retention time during dry summer periods are offset by storage. Storage requirement is 2
months average demand (2031). Positive potential for increased biodiversity in the Bord na Mona
former bogs. Avoidance of potential issues (Options A, D & E) on Shannon Callows.
Direct impact on SAC and SPA but no significant issues identified relating to increased low flow
durations, retention times or changes in water levels. Abstraction will result in 1% - 2% reduction in
(hydro) renewable energy. Pipe route length is 158km.
Direct impact on SAC and SPA. Issues relating to increased low flow durations and retention times
during dry summer periods are largely offset by storage. Storage required is 4 months. Positive
potential for increased biodiversity. Pipe route is 104km.
Direct impact on SAC and SPA. No significant issues relating to levels or low flows but potential for
marginal increases in retention time during dry summer periods. 1% - 2% reduction in (hydro)
renewable energy.
Direct impact on SAC and SPA. Issues relating to increased duration of low flow periods and
increased retention times during dry summer periods. Abstraction 250Ml/d (Ph1) requires
modification to sluice operation as per Option A. Pipeline is 171km which is longer than Option C.
Two treatment plants increase infrastructure footprint. 1% - 2% reduction in energy.
Direct impact on SAC or SPA and major environmental and social issue with regard to
impoundment.
No direct impact on an SAC or SPA. Issues relating to brine dispersal and increased greenhouse
gases. Carbon footprint based on energy from national grid containing mix of renewable / fossil
fuel. CER Regulatory Framework prohibits direct use of dedicated renewable energy unless colocated.
Direct impact on SAC and SPA. Issues relating to increased low flow durations and downstream
retention time during dry summer periods. Option can physically meet the objective of the strategy
of 350Ml/d but requires modification to sluice operations in order to comply with regulations. Sluice
modifications increase flood/environmental risk around Lough Ree and on the Callows.
Groundwater for public supply (25Ml/d-50Ml/d) is not available in sufficiently sustainable quantities
to cover long-term needs.
Sustainable availability of water from this option (20Ml/d - 40Ml/d) is too low to be considered as a
strategic supply source.
111
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F02
Water Supply Project – Dublin Region
Table 10.6
Option
The Plan
Environmental Assessment (HDA)
Description
Option F
F1 & F2
Lough Derg + Storage (Bog)
Option C
Parteen Basin
Option B
Lough Derg
Option H
Desalination
Option E
Lough Ree + Storage (Bog)
Option G
Lough Ree + Impoundment
Option A
Lough Ree
Option D
Lough Ree (Phase 1) /
Lough Derg (Phase 2)
Option I
Groundwater
Option J
Liffey - Barrow Conjunctive
Use
MDW0158RP0091
Habitats Directive Assessment – HDA
Impacts on European Designated Sites
Direct impact on SAC and SPA. No significant issues relating to low flows. Potential for increased
retention time during dry summer periods are offset by storage. Storage requirement is 2 months.
Positive potential for increased biodiversity in the Bord na Mona former bogs. Avoidance of
potential issues on Shannon Callows between L Ree and L Derg.
Direct impact on SAC and SPA but no significant issues relating to increased low flow durations,
retention times or changes in water levels. 158km pipeline has flexible route re SPAs, SACs etc.
Direct impact on SAC and SPA. No significant issues relating to levels or low flows. Potential for
marginal increases in retention time during dry summer periods. 122km pipeline has flexible route
re SPAs, SPCs etc.
No direct impact on an SAC or SPA, only potential for indirect impact.
Direct impact on SAC and SPA. Issues relating to increased low flow durations and retention times
during dry summer periods are largely offset by 4 months storage at average extraction rates.
Positive potential for increased biodiversity. Sluice issues still remain a potential issue in dry
periods.
Direct impact on SAC and SPA. Issues relating to increased low flow durations and retention times
during dry summer periods are largely offset by impoundment. Impoundment location is not SPA or
SAC and location is not assessed in HDA.
Direct impact on SAC and SPA. Issues relating to increased low flow durations and d/s retention
time during dry summer periods. Option can meet the objective of the strategy of 350Ml/d but
requires modification to sluice operations in order to comply with regulations. Sluice modifications
increase flood/environmental risk round Lough Ree and on Callows.
Direct impact on SAC and SPA. Issues relating to increased duration of low flow periods and
increased retention times Abstraction of 250Ml/d (Ph1) requires modification to sluice operation as
per Option A.
Groundwater for public supply (25Ml/d-50Ml/d) is not available in sufficiently sustainable quantities
to cover long-term needs.
Sustainable availability of water from this option (20Ml/d - 40Ml/d) is too low to be considered as a
strategic supply source.
112
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F02
Water Supply Project – Dublin Region
Table 10.7
Economic Assessment
Option
Description
Option A
Lough Ree
Option D
Lough Ree (Phase 1) /
Lough Derg (Phase 2)
Option B
Lough Derg
Option F 2
Lough Derg + Storage
(Portarlington)
Option E
Lough Ree + Storage
(Rochfortbridge)
Option F 1
Lough Derg + Storage
(Rochfortbridge)
Option C
Parteen Basin
Option G
Lough Ree + Impoundment
Option H
Desalination
Option I
Groundwater
Option J
Liffey - Barrow Conjunctive
Use
MDW0158RP0091
The Plan
Economic Assessment
(Capex, Opex and Cost of Water delivered - NPV @ 5% over 25 year operation)
Capex € 440m-€480m ; Opex € 100m-€130m ; Whole Life Cost € 540m-€610m ;
Cost of water delivered € 0.27/m3 - € 0.30/m3
Capex € 450m-€490m ; Opex € 110m-€140m ; Whole Life Cost € 560m-€630m ;
3
Cost of water delivered € 0.27/m3 - € 0.30/m .
Capex € 490m-€540m ; Opex € 110m-€140m ; Whole Life Cost € 600m-€680m ;
Cost of water delivered € 0.30/m3 - € 0.34/m3.
Capex € 520m-€560m ; Opex € 120m-€160m ; Whole Life Cost € 640-€720mm ;
Cost of water delivered € 0.32/m3 - € 0.36/m3.
Capex € 530m-€580m ; Opex € 120m-€150m ; Whole Life Cost € 650m-€730m ;
Cost of water delivered € 0.32/m3 - € 0.36/m3.
Capex € 530m-€570m ; Opex € 120m€160m ; Whole Life Cost € 650m-€730m ;
Cost of water delivered € 0.32/m3 - € 0.36/m3.
Capex € 590m-€650m ; Opex € 130m-€170m; Whole Life Cost € 720m-€820m ;
Cost of water delivered € 0.35/m3 - € 0.41/m3.
Capex € 570m-€620m ; Opex € 120m-€160m ; Whole Life Cost € 690m-€780m ;
Cost of water delivered € 0.45/m3 -€ 0.50/m3.
Capex € 600m-€650m ; Opex € 320m-€350m ; Whole Life Cost € 920m-€1,000m ;
3
Cost of water delivered € 0.61/m3-€ 0.67/m .
Groundwater for public supply (25Ml/d-50Ml/d) is not available in sufficiently sustainable quantities
to cover long-term needs.
Sustainable availability of water from this option (20Ml/d - 40Ml/d) is too low to be considered as a
strategic supply source.
113
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Water Supply Project – Dublin Region
Table 10.8
Option
Socio – Economic Assessment
Description
Options F
Lough Derg + Storage (Bog)
Option C
Parteen Basin
Option B
Lough Derg
Option E
Lough Ree + Storage (Bog)
Option D
Lough Ree (Phase 1) /
Lough Derg (Phase 2)
Option A
Lough Ree
Option H
Desalination
Option G
Lough Ree + Impoundment
Option I
Groundwater
Option J
Liffey - Barrow Conjunctive
Use
MDW0158RP0091
The Plan
Socio-Economic Assessment
Navigation /Tourism / Agriculture / Angling / Local Economy etc.
Abstractions can be managed in conjunction with ESB to ensure no change in water levels.
Abstraction would probably increase focus on water quality in Lough Derg which could improve its
longterm tourism and angling potential and potentially benefit the local economy. Storage in former
bogs enhances the environmental rehabilitation process by re-creating nature and providing
increased amenity.
Abstractions can be managed in conjunction with ESB to ensure no change in water levels.
Abstraction would probably increase focus on water quality issues in Parteen Basin which could
help improve its longterm tourism and angling potential which in turn could benefit the local
economy.
Abstractions can be managed in conjunction with ESB to ensure no change in water levels.
Abstraction would probably increase focus on water quality and water management issues in Lough
Derg which could help improve its longterm tourism and angling potential which in turn could benefit
the local economy.
Enables abstractions from Lough Ree to be tailored to match flows resulting from rainfall. Minimum
flows (50Ml/d) required in dry periods may require modification to sluice operations. Storage has
potential to enhance environmental rehabilitation of former bogs.
In order to ensure that water levels would remain within the requirements of the ESB Regulations it
would be necessary to restrict abstractions in dry periods or else change current operation of
sluices. Consensus on sluice operation changes would be difficult since Navigation & Flooding
interests currently compete. Changes would increase flooding/environmental risk around L Ree and
downstream of Athlone on the Callows and would be detrimental to tourism.
In order to ensure that water levels would remain within the requirements of the ESB Regulations it
would be necessary to restrict abstractions in dry periods or else change current operation of
sluices. Consensus on sluice operation changes would be difficult since Navigation & Flooding
interests currently compete. Changes would increase flooding/environmental risk around Lough
Ree and downstream of Athlone on the Callows and would be detrimental to tourism.
Relatively large infrastructure footprint in coastal location. High carbon footprint. Brine Dispersion
requires careful management. Detrimental to international “green” image of Ireland.
Enables abstractions from Lough Ree to be tailored to match flows resulting from rainfall. Minimum
flows (50Ml/d) required in dry periods (to keep raw water moving in pipes) may require modification
to sluice operation. Impoundment would have negative socio - economic effects.
Groundwater for public supply (25Ml/d-50Ml/d) is not available in sufficiently sustainable quantities
to cover long-term needs.
Sustainable availability of water from this option (20Ml/d - 40Ml/d) is too low to be considered as a
strategic supply source.
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Water Supply Project – Dublin Region
The Plan
10.2.1 Summary of Sustainability Analysis & Strategic Environmental Assessments
Table 10.9 at the end of this section, summarises the ‘relative rating’ of each water supply option with
respect to the sustainability & environmental evaluation criteria. The Options are ranked relative to
each other with the preferred option (Option F2) having the highest degree of compliance across all
sustainability & environmental evaluation criteria. A brief summary of the advantages / disadvantages
of each option is outlined in Section 10.2.2. The Options are discussed in reverse order – least
preferred to most preferred.
10.2.2 Summary of Option – Advantages / Disadvantages
Options I & J
Option I (Groundwater) and Option J (Liffey Barrow) were not considered further when technical &
modelling assessments identified that neither option could provide the capacity for meeting supply
needs. Sustainable yields for Groundwater (§ 50Mld) or Liffey Barrow (§ 20Mld) fall far short of the
longterm supply needs of the Dublin Region (300Mld at 2031).
Options A & D
Option A (Lough Ree) and Option D (Lough Ree / Lough Derg phased) were identified by
‘Appropriate Assessment’ under the Habitats Directive as likely to have a significant impact on
designated sites. Lough Ree is a Special Area of Conservation (SAC) and Special Protected Area
(SPA). Technical & modelling studies identified that abstractions from Lough Ree (250Mld – 300Mld)
could only be implemented within the ESB Regulations (for water levels) by changing the current
operation of the sluices on Athlone Weir. Changing the sluice operations would retain greater volumes
of water in the lake to facilitate abstraction but this in turn would increase flooding risk downstream on
the Shannon callows. Changing the sluice operations would also likely meet with local stakeholder
resistance as there is little consensus in relation to current operational practice which is a best fit for
meeting competing interests without fully satisfying any particular interest. Abstraction would also give
rise to extended durations of minimum flow periods which could also significantly impact on the
ecology of the callows.
Options E & G
Option E (Lough Ree & Storage) and Option G (Lough Ree & Impoundment) enable variable
abstractions from Lough Ree with higher abstractions during high flow periods (Winter & Spring) and
reduced abstractions in low flow periods (Summer & Autumn). These arrangements would lower the
‘flooding risk’ and ‘extended durations of minimum flows’ (associated with Options A & D) but would
not eliminate them completely and modifications to sluice operations would still be required which
could result in significant stakeholder resistance. The levels of external storage required would be
extensive (4 months average flow at 2040) and the cost of the overall schemes would end up being
more expensive than Lough Derg Options where much greater control on water management is
available (through ESB Ardnacrusha) combined with much greater availability of water.
Option H
Desalination of sea water is technically feasible and is increasingly being used in countries which are
water stressed and which do not have alternative surface water or groundwater sources available to
them. Drinking water produced from desalination is expensive because of high initial capital costs of
intakes / outfalls/ desalination process plants and also because of the high running costs due to the
process energy required. An east coast desalination plant (as per Option H) would use, on average,
MDW0158RP0091
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Water Supply Project – Dublin Region
The Plan
3 to 4 times the amount of energy required for Shannon based schemes. A desalination water supply
option to produce 300Mld would cost in the order of €1bn vs €600m - €700m for technically
equivalent Shannon options (eg Options C, B & F2). There are environmental issues associated
with high energy use and potentially with large scale continuous brine dispersion. There are also
perceived aesthetic issues involved in relation to the suitability of the sea as a source of drinking
water and also potentially with the taste of the finished product.
Options B, F2 & C
Option B (northern Lough Derg, no storage) is a lower cost option than Option F2 (northern Lough
Derg, with external storage) or Option C (Parteen Basin, no storage). However, Option B has
potential environmental issues regarding increases in Lough Derg residence times which could result
from the proposed levels of abstraction (350Mld), particularly in extended low flow periods. Option B
also lacks back up, in the event of an unforeseen pollution incident on the Shannon or other
unforeseen events.
Option F2 is essentially Option B with external storage. The incorporation of external raw water
storage into the water supply proposals provides the following advantages:
x No increased residence time or related environmental issues would arise during low flow
periods in Lough Derg as storage provides a facility to match abstractions to flows – higher
in Winter / lower in Summer etc Abstractions can be ceased altogether during extended
periods of low flow. Details of the abstraction regime will be established through
Hydrodynamic and Water Quality Modelling during EIA – the next stage in the project’s
development
x Back-up in the event of unforeseen circumstances is provided (eg major pollution incident)
x Storage provides a facility to manage peak demand in Dublin from Garryhinch rather than
from the Shannon. This involves potential savings in infrastructure and operation costs.
x Storage facilitates relocation of substantial infrastructure footprint (eg Treatment Plant) from
the sensitive Shannon landscape to Garryhinch where it can be accommodated without
significant visual impact
x Storage facilitates reductions of proposed treated water storage facilities in Dublin (these
savings are equivalent to the cost of the raw water storage)
Option C (Parteen Basin, no storage) does not give rise to residence time increase issues in Lough
Derg since the abstraction location is downstream of Lough Derg. The principal drawback of Option
C is the increased length (and associated pumping and other costs) of pipelines required to transmit
water to the Dublin Region (158 km from Parteen Basin vs 124 km from northern Lough Derg).
There is also no back-up in the event of unforeseen circumstances.
However, the main advantage of Option C (no residence time increase issues) can be achieved by
Option F2 (with the assistance of ESB Ardnacrusha) at considerably less expense because of the
shorter pipeline lengths involved and savings from reduced pumping energy costs.
MDW0158RP0091
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The Plan
10.3 RECOMMENDED PREFERRED OPTION
Based on the conclusions above, the recommended option for meeting the Dublin Region’s longterm
water supplies is Option F2.
Option F2 is outlined in Figure 10.1 below in schematic form.
Figure 10.1
Option F2 Northern Lough Derg & External Storage
Lough
Ree
Termination Point
Reservoir
Peamount
Reservoir
River
Shannon
Lough
Derg
Parteen
Basin
Storage
(Raw Water )
62
R km
Pr aw
Ra
tw
e
ss Wa in
& w
Pu W
ur ter 14
e: – 00
m ate
pi r
15 12 ĭ
ng Ab
-2 4k pi
0b m p
St str
ar to elin
at ac
i o ti
ta e
n on
l
Garryhinch Bog
(Bord na Mona)
Saggart
Reservoir
54
D km
W
15
Pr rink tw
a
& te
In km
es in in
Tr r T
su g
Dr teg tw
12
ea re
W
r
r
i
0
i
P
e: at 0
te at
re nki atio n 1
d m
10 er ĭ
ss ng n 00
W en
-2 – pip
u
– 0ĭ
at t
W
0b 10 e
re
er Pl
: 5 ate 30k p
ar 6k lin
PS an
s m e
-1 r m ipe
t
0
to lin
to
ba
ta e
ta
l
rs
l
River Shannon
MDW0158SK53D08
10.3.1 Option Description
Shannon Option F2 involves raw water abstraction from northern Lough Derg, pumping of raw
water to a ‘cutaway bog’ site near Portarlington (Garryhinch Bog - owned by Bord na Mona), raw
water storage facilities at the site, water treatment and pumping facilities at the site and pipelines to
convey treated water from the site to the Midlands and to the Dublin Region. Combined raw water
and treated water pipelines are approx 130km in length (including pipelines from the Termination
Reservoir to Saggart & Peamount Service Reservoirs). Storage facilities will accommodate at least 2
months average supply requirements at 2030 – 2040 (12 million m3) which would limit the need for
abstractions from Lough Derg at times of extreme low flow. This option has the capability of
supplying raw water or treated water to Midlands Local Authorities along the pipeline route from the
Shannon to Dublin. The proposed 2031 level of abstraction for Dublin & the Midlands is approx 2%
of the average Shannon flow in Lough Derg.
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10.3.2 Merits of Recommended Option F2
Option F2 is the minimum cost option which is capable of meeting the Dublin Region’s long term
water supply needs up to 2031 and beyond, whilst complying with all significant environmental
constraints. The incorporation of large scale external raw water storage into the overall water supply
scheme (through use of BNM cutaway bogs), in conjunction with abstraction of raw water from Lough
Derg’s storage (controlled by ESB), ensures that the solution is technically robust and capable of
meeting the long term demand requirements of the Dublin & Midland Regions, in an environmentally
sustainable and cost effective manner.
The recommended solution has evolved through the Strategic Environmental Assessment and
Habitats Assessment processes, involving considerable stakeholder input through formal public
consultation and extensive engagement with multiple Shannon based stakeholder groups over a 5
year period. Consequently, from a planning and implementation perspective, it is a lower risk and a
more cost effective option than all other available alternatives considered. The recommended solution
also benefits local Midland’s communities through the development of an Eco Park associated with
raw water storage, provision of (indirect) water supplies to the Royal Canal and provision of water
supplies particularly to Laois, Offaly and Westmeath County Councils. Option F2 impacts on 5
counties between the Shannon and Dublin and if implemented has the potential for making strategic
water supplies available in these counties or neighbouring counties.
A number of environmental / technical & economic advantages of the recommended scheme are
outlined as follows;
10.3.2.1 Environmental and Social Advantages
x
Operational lake levels in Lough Derg are not affected by water abstractions for Dublin as
ESB hydropower generation activities at Ardnacrusha provide counter balancing effects
x
The proposed raw water storage at Garryhinch creates a Midlands lake with water
abstracted during high flow & flooding periods on the Shannon
x
‘Abstraction-related’ increased residence times and associated environmental issues, which
represented a significant stakeholder concern in Lough Derg, are minimised during low flow
periods as raw water storage at Garryhinch (cutaway bog storage site) allows abstractions
to be reduced or eliminated when Shannon flows are extremely low
x
Storage facilitates relocation of substantial infrastructure footprint (e.g. Treatment Plant)
from the sensitive Shannon landscape to the Midlands bog site where it can be
accommodated without significant visual impact
x
Supply of treated water to Westmeath (Mullingar) indirectly enables the upgrading of the
water supply to the Royal Canal by releasing Lough Owel flows from water supply to support
the canal flows
x
Large scale raw water storage will secure the Dublin Region water supply, while supporting
the development of water based amenities and environmental parks with knock – on tourism
benefits for the Midlands as a secondary benefit. Proposed eco-tourism facilities at the site
are being modelled on similar facilities which were created at Rutland in the UK by Anglian
Water where bird watching, angling and water sports have considerably enhanced the
economic earning potential of the region. The core range of ideas and uses for the
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Garryhinch raw water storage reservoir are unlikely to differ markedly from those seen
elsewhere. Typologies and concepts are likely to include;
x
o
Non motorised water
canoeing/kayaking
o
Natural Environment: Bird watching, ecology zones and interpretation and angling,
perhaps a lido and beach for peak summer season activity and events
o
Trails: Cycle, walking and jogging
o
Events: sport related (Triathlon, open water swimming) and other (concerts,
education, special interest groups)
o
Landscape Design: high quality parkland surrounding the reservoir and water
features
o
Education: Education centre and officer to accommodate education tours in relation
to water conservation and treatment.
sports:
Dingy
sailing,
windsurfing,
kite
surfing,
This reservoir is proposed to be the first dual purpose reservoir in Ireland designed from the
very beginning to meet two core functions i) water supply and ii) recreation & leisure.
o
It will be designed to offer ease of recreational use and optimal access to the public
o
It will factor in security, and health & safety issues
o
It will have high quality integrated management and be a key element of the tourism
offer and will be of relevant visitor economy groups at the local, region and national
level
o
It will seek to develop links and networks with other similar reservoir destinations
internationally.
10.3.2.2 Technical & Economic Advantages
x
Large scale raw water storage at Garryhinch provides back-up in the event of unforeseen
circumstances arising (e.g. major pollution incident on the Shannon) increasing the
robustness of the supply to the Region
x
Storage provides a facility to manage peaks in water demand from the Midlands
(Garryhinch) rather than from the Shannon. This involves savings in infrastructure and
operation costs
x
Raw water Midlands storage facilitates reductions in treated water storage needs in Dublin
because of the scale of strategic storage proposed for Garryhinch
x
Raw water storage facilitates optimum use of renewable power (wind) to pump raw water,
accommodating the intermittent nature of this energy source
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10.4 EIA & HDA OF RECOMMENDED / PREFERRED OPTION
Option F2 is recommended subject to full Environmental Impact Assessment (EIA) and Habitats
Directive Assessment. Certain monitoring and mitigation measures will have to be incorporated to
ensure that there is minimal impact on the environment. Section 11 outlines the monitoring and
mitigation measures that will need to be incorporated into the EIA of Option F2. The EIA & HDA will
involve further public consultation in relation to project details.
10.5 ADOPTION OF PREFERRED OPTION & SEA STATEMENT
Approval of Technical Proposals (by DCC / DEHLG) for the recommended preferred option will
enable formal adoption of the option by DCC (and other Local Authorities) as required by the SEA
process and legislation. Following adoption, the publication of a formal SEA Statement is required to
complete the SEA statutory process. This statement must be made available to the public. The
statement sets out as a minimum:
-
The rationale behind the selection of the recommended water supply option (plan)
including the consideration of feedback received during public consultation
-
How environmental considerations are to be incorporated into the plan
-
How public consultation has been incorporated into the plan
-
Any monitoring requirements and mitigation measures (if appropriate)
10.6 STATUTORY PLANNING PROCESS
Following publication of the SEA Statement, discussions can commence with An Bord Pleanala
regarding the appropriate legislative process for securing the necessary planning consents for the
various elements which make up the totality of the recommended water supply option. The planning
process will again involve formal public consultation at different stages in the project’s development.
The preparation of a Planning Application will take approx 18 months and the Planning Process
involving An Bord Pleanala could take up to 2 years depending on the methodology to be adopted by
An Bord Pleanala for progressing the application.
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Table 10.9
The Plan
Evaluation Summary / Ranking of Options
Evaluation Summary / Ranking of Options
Technical
Option
Environmental
Economic
Socio Economic
Source
Infrastructure
SEA
Habitats Dir
(HDA)
Capex / Opex /
Cost of Water
Delivered
Navigation /
Tourism
Agriculture/
Angling Local
Economy /
Flooding etc
++
+
++
~
~
-
+
+
~
++
-~
++
++
~
+
+
--
~
~
~
~
---
~
+
-~
-++
++
++
+
+
~
--
Description
Option F
Lough Derg + Storage (Bog)
Option B
Lough Derg
Option C
Parteen Basin
Option H
Desalination
Option E
Lough Ree + Storage (Bog)
Option G
Lough Ree + Impoundment
Option D
Lough Ree (Phase 1) /
Lough Derg (Phase 2)
Option A
Lough Ree
Option I
Groundwater
N/A
N/A
N/A
N/A
N/A
N/A
Option J
Liffey - Barrow Conjunctive Use
N/A
N/A
N/A
N/A
N/A
N/A
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11 MONITORING AND MITIGATION
11.1
INTRODUCTION
The strategic environmental assessments undertaken on Option F2 have shown that its
implementation is unlikely to give rise to significant environmental impacts. However, the SEA
Environmental report suggests a number of further measures that would be required in order to
determine with certainty that the environmental impacts from the implementation of the proposed Plan
would be minimal. These measures, set out below, will have to be undertaken as part of the EIA
process which is the next stage in the development of the Dublin Region water supply project. This
section outlines the monitoring already in place and the proposed monitoring/ mitigation measures
required for the preferred option, Option F2.
11.2 MEASURES ALREADY IN PLACE
11.2.1 Water Flows/Levels
Flow monitoring equipment was installed on the River Shannon, at Athlone as part of the mitigation
measures identified in SEA Phase l. Consultations took place with the EPA, Westmeath County
Council, the Shannon River Basin District, ESB and Waterways Ireland as to the most appropriate
equipment and an optimum location for its installation. The flow meter monitors both flow and water
levels at intervals of approximately every 15 minutes. The instrument’s readings can be used to verify
the accuracy of the weir equation calculations at Athlone and provide ongoing quality assurance in
relation to the hydrological model of the Shannon system, which has been built by RPS.
11.3 PROPOSED MONITORING AND MITIGATION MEASURES
11.3.1 Conservation Measures
Promotion of water conservation initiatives are recommended as follows;
x
Implementation of domestic metering & volumetric charging
x
Encouragement of householders to use water saving appliances etc.
x
Education & Awareness programmes
x
Investigations into feasibility of retrofitting existing houses with water saving appliances
x
Continuation of water network rehabilitation programmes in the Dublin Region
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11.3.2 Landscape
A landscape architect will be consulted during the detailed design of all above ground infrastructure so
they are designed in sympathy with the surrounding landscape.
11.3.3 Energy
Energy has become an increasing resource concern and the monitoring and management of energy is
fundamental to the efficient performance of the project. Renewable energy sources and energy
efficient measures to be maximised where possible.
11.3.4 Working Groups / Consultees
An independent working group (advisory council) should be established to identify the detail of
monitoring programmes, outlined in the following sections. The working group could be comprised of
members of statutory bodies such as the ESB, Waterways Ireland, National Parks Wildlife Service,
Inland Fisheries Ireland, the Environmental Protection Agency, River Basin Districts, the Lough Derg
Science Group and other relevant bodies to establish a monitoring framework.
The National Parks and Wildlife Service and Inland Fisheries Ireland will be included as consultees in
the preparation of the EIS.
11.3.5 ESB Agreement
To prevent any significant alteration to the existing hydrology of the River Shannon below Parteen
Weir, the existing regime within the old channel needs to be maintained at the expense of water
supply quantities to the ESB for power generation at Ardnacrusha. For the Lower River Shannon
(below Parteen Weir) the current hydrological regime should be preserved to ensure that existing
habitats that are dependent on inundation are maintained. ESB have a long history of cooperation with
Local Authorities in the provision of water supplies and have indicated that they are happy to make
arrangements with DCC which ensures that any water taken from Lough Derg is at the expense of
power generation at Ard na Crusha.
11.3.6 Bog Storage
Lough Derg has a European designation in relation to its ecological habitats and species. Direct
abstraction from Lough Derg in prolonged low flow conditions, whilst not impacting lake levels, could
potentially marginally impact on Lough Derg SAC and SPA as a result of a minor increase in retention
times, which may slow down the flushing of nutrients / pollutants through the lake and potentially could
impact on aquatic plant and animal species. However, with the inclusion of external storage which
facilitates lowering or eliminating abstractions during low flow periods, impacts are minimised and are
not anticipated to be significant. The proposed reduced abstractions during the dryer periods (by the
provision of storage facilities) significantly reduce any possible potential negative impacts on the
ecology of the lake.
11.3.7 Phytoplankton Dynamics
The use of storage mitigates against an increase in residence times. The possibility that minor
changes to residence time may lead to significant changes in nutrient and phytoplankton dynamics in
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Lough Derg is considered unlikely; however, given the importance of the Shannon System the
situation with regard to these issues should be subject to on-going monitoring. Water circulation in
Lough Derg leads to wide spatial variation in nutrient supply, primary production (phytoplankton) and
degree of deoxygenation in deep water. To date, research in Lough Derg has focused mainly on plant
and animal communities and a limited range of water quality parameters. There has been limited work
done on hydrodynamics or the effects of seasonal and climatic variations on circulation and mixing.
The response of the phytoplankton dynamics of the proposed abstraction scheme appears to be the
greatest uncertainty, when predicting their likely impacts, both in terms of magnitude of response and
implications. In order to address this issue adequately, consistent time-series of data on nutrients and
phytoplankton community (biomass and diversity) may be required. The monitoring methodology
should take account of the seasonal and tidal variability as a minimum and thus the data should be
collected over a minimum period of one year. Some data is being collected by the EPA as part of the
requirement to comply with the Water Framework Directive, thus the monitoring strategy should be
adjusted to build upon the existing data. Based on the time-series, a biological model of the
phytoplankton dynamics should be established. In order to be reliable, the model would also have to
take into account top-down control and account for grazing pressures. The zebra mussel is considered
one of the dominant factors in the nutrient dynamics of the lake and their filtering capacity within the
study area under the proposed abstraction regime should be addressed and factored into the
phytoplankton model. Such data (time-series and biological model) would allow more accurate
prediction of the biological effects of the proposed abstraction scheme.
11.3.8
Ecological Study on Bog Storage
An ecological study is recommended in order to examine the possibilities for ecological design,
fisheries, habitat recreation area etc for the raw water bog storage area. The development of the
storage area should be designed with reference to the environmental management plan for Lough
Boora Parklands, Co. Offaly (Bord na Mona). Emphasis should be placed on creating a mosaic of
semi-natural habitats appropriate to the cutaway bog land through natural regeneration. An
environmental management plan will be developed for the bog storage.
Bord Na Mona have developed amenity plans for Garryhinch which include raw water storage – these
are available on the BNM website www.bnm.ie
11.3.9 Shannon System Monitoring
Monitoring equipment has already been installed in the River Shannon at Athlone in order to record
discharge. Data collection equipment should be considered for other locations throughout the system
to gather long-term data on water levels, flows, temperatures and residence times within both the
rivers and lakes of the Shannon System.
For the Lower River Shannon (below Parteen Weir) the current hydrological regime should be
preserved to ensure that existing habitats that are dependent on inundation are maintained.
To prevent any significant alteration to the existing hydrology of the River Shannon below Parteen
Weir, the existing regime within the old channel needs to be maintained at the expense of water
supplies to the ESB.
Ongoing monitoring of the Shannon’s flows, water levels and residence times will be required.
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11.3.10
The Plan
Pollan Survey
Pollan is an endangered species recorded in the past on the Shannon system. Concerns have been
raised as to the Pollan stocks in Lough Derg and Lough Ree. However the possible effects of water
abstraction on its stocks will have to be addressed adequately and this is not possible with the limited
knowledge there is at present. A Pollan survey will be carried out , where necessary, to ensure that no
Pollan spawning grounds are endangered by the insertion of the abstraction structure.
11.3.11
Invasive Species
The best available methods of preventing the transfer of invasive species will be employed
(pressurised micro – filtering). Detailed investigations and best practice techniques will be employed
so as to inhibit the transfer of invasive species, in particular the zebra mussel.
11.3.12
Hydrological Connections
The hydrology of the storage area should remain separate from the surrounding regional groundwater
and surface water to limit the potential for mixing inter-catchment waters.
11.3.13
Compliance with Water Framework Directive
The Water Framework Directive (WFD) has influenced this WSP-DR Plan and the objectives of the
WFD were taken into account by the WSP-DR. Subsequent to the publication of the 2008 draft Plan
and associated environmental reports for the WSP-DR, the draft River Basin Management Plans
(RBMPs) were issued for public consultation. The final RBMPs for the Eastern River Basin District and
the Shannon International River Basin District (ShIRBD) have been are reviewed and incorporated,
where appropriate into the WSP-DR final Plan. A summary of this assessment and the possible
interaction/relationship/connection/conflict with the WSP-DR is outlined in Section 4.
Option F2 (Northern Lough Derg + External Storage) proposes to pump excess water from the
Shannon in times of high flows and store the excess water in cutaway bogs in the midlands. This
abstraction regime enables reduced levels of abstraction in low flow periods (summer months).
Abstraction from the Shannon for the Dublin Region also has the potential to supply midlands local
authorities with some of their water requirements which, in turn, could free up currently potentially
stressed water bodies such as Lough Owel to provide supplies to the Royal Canal. These proposals
are in correlation with the draft recommendations and measures made by the RBMPs in relation to
abstraction generally.
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