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WCWSS
The Western Cape Water Supply System
•
•
•
•
•
Serves more than 3 million people
– Supply to Cape Town and some West Coast, Boland,
Swartland and Overberg towns
Irrigation
– In the Berg, Eerste and Riviersonderend rivers
– Production of 50% of SA’s irrigated agricultural export
High economic growth and migration into the system area
Infrastructure owned by the DWAF, City of Cape Town (CCT) &
Eskom
Berg Water Project under construction near Franschhoek
WCWSS characteristics
• 90% runoff in Winter (May to Oct)
• 70% requirements in summer (Nov to Apr)
• 50% of system dams’ storage needed to store winter
water for usage in summer
• 50% of system dams’ storage provides carry-over
storage for drought periods
• Dams are operated to minimise spillage
• Droughts are managed by progressively restricting
supplies
PURPOSE OF THE RECONCILIATION
STRATEGY
• To update and review water requirements and
interventions to meet requirements
• To engage stakeholders and the general public
• To develop toolkits to assist with the future
reconciliation of supply and requirement
• To provide a guide for decision-making towards
effective reconciliation of supply and requirement
• To recommend preparatory measures, actions and
assign responsibilities
Management of Study
National Water Resource Planning
Study Management
Steering Committee
Professional Service Provider
 DWAF HO
 DWAF RO
Public participation
 CCT
 Saldanha Mun.
 Provincial Dept.
of Agric
 Province
RECONCILIATION
STRATEGY STUDY
Selected
Stakeholder
input
Institutional Planning Process
Provincial Integrated Development Plan
Berg Catchment
Management Strategy
CCT’s Integrated Development Plan (IDP)
Other WSDPs
CCT WSDP
CCT WC/WDM Strategy
Reconciliation Strategy
NEWSLETTER 1
PUBLIC MEETING
To identify and provide feedback on interventions
PUBLIC PROCESS FOLLOWED
NEWSLETTER 2
August 2005: Screening of
Interventions Workshop
PUBLIC MEETING
To provide feedback on interventions for comment
Input from the Berg and Breede-Overberg
CMA Reference Groups
Refine reconciliation scenarios and
strategy content through stakeholder
workshops and technical focus
groups
NEWSLETTER 3
Summary of strategy to public for comment
Input from the Berg and Breede-Overberg
CMA Reference Groups
DWAF WRFMC
CCT Portfolio Committee
CCT Mayco and Council
Berg CMA Reference Group
Determine and analyse a range of
implementation scenarios
NEWSLETTER 4
Obtain public feedback on scenarios through
press release and newspaper advert
PUBLIC MEETING
To present the Reconciliation Strategy and
selected interventions for further study
Strategy Steering Committee to consider comments
STRATEGY THEMES
Water
Requirements
Implementatio
n and
Performance
monitoring
Water Use
Efficiency
Water Availability
Monitoring
and
Information
Management
Strategy
Comparison
of supply
and
requirement
Stakeholder
Engagement
Protection
and
Management
Selection of
intervention
s
Structure of Study
Key Reports
Reconciliation
Strategy
9 Themes each
containing
•Key issues
•Objectives
•Approach
•Action
Determination of Future
Water Requirements
Scenario Planning for
Reconciliation of Supply
and Requirement
Supporting Reports
WC/WDM
•Responsibility
•Programme
Treated Effluent use
Bulk Water Supplied by the CCT
630
Previous unconstrained
curve
Million cubic metres/annum
580
530
480
High Water Requirem ent
Curve
430
380
330
280
230
180
Actual
Low Water
Requirem ent Curve
Low Water
Dem and
Curve
(DWAF/CCT
Agreem ent)
130
1978 1981 1984 1987 1990 1993 1996 1999 2002 2005 2008 2011 2014 2017 2020
Options/ Interventions Identified
CCT 8-yr WC/WDM Strategy
Additional Longer-term WC/WDM
Groundwater Interventions
Surface Water Interventions
Treated Effluent use
Desalination
CCT 8-yr WC/WDM Strategy
Additional Longer-term WC/WDM
Groundwater Interventions
Surface Water Interventions
Treated effluent use
Desalination
 Pressure Reduction
 Leak Detection and Repair
 Meter management
and replacement
 Consumer awareness
 School Education
 Plumbing retro-fit prg
 Support for large consumers
 Re-use: Parks and Industry
 Management Information
System
 Upgrade telemetry system
CCT 8-yr WC/WDM Strategy
 Tariffs, metering and
credit control
Additional Longer-term WC/WDM
 Eliminate AFUs
 Promotion of private
Groundwater Interventions
Surface Water Interventions
Treated Effluent use
Desalination
boreholes & wells
 Leak detection
 Water Efficient Fittings
 User Education
CCT 8-yr WC/WDM Strategy
 Newlands Aquifer
 Cape Flats Aquifer
Additional Longer-term WC/WDM
 West Coast Aquifers
 TMG Aquifer
Groundwater Interventions
Surface Water Interventions
Treated Effluent use
Desalination
CCT 8-yr WC/WDM Strategy
 Voëlvlei Phase 1
 Michell’s Pass Diversion
Additional Longer-term WC/WDM
 24 Rivers Dam
 Upper Wit River Diversion
Groundwater Interventions
Surface Water Interventions
Treated Effluent use
Desalination
 Raise Steenbras Lower Dam
 Upper Molenaars
CCT 8-yr WC/WDM Strategy
Additional Longer-term WC/WDM

Treated Effluent use Irrig./ind

Dual Reticulation

Commercial Irrig. Exchange

Treated Effluent use to
Potable standards
Groundwater Interventions
Surface Water Interventions
Treated Effluent use
Desalination

Berg River Exchange
CCT 8-yr WC/WDM Strategy
 CCT Pilot Plant
 Desalination Plant
Additional Longer-term WC/WDM
Groundwater Interventions
Surface Water Interventions
Treated Effluent use
Desalination
Scenario Planning
The objective of the Scenario Planning
Process is to identify, evaluate and
assess alternative groupings and
phasing of interventions so as to
determine the potential impacts and
benefits of possible combinations of
interventions to reconcile water supply
and requirement in the WCWSS, up to
2030.
SCENARIO 1
NO WC/WDM
SCENARIO 2
SCENARIO 3
CCT WC/WDM
strategy
implemented
CCT WC/WDM
strategy
implemented &
additional
WC/WDM
interventions
ILLUSTRATES IMPACT OF WC/WDM ON TIMING OF
IMPLEMENTATION OF SUPPLY INTERVENTIONS
SCENARIO
DESCRIPTION
No WC/WDM, but all supply interventions can be implemented
Scenario1
Objective: To determine the impact of not implementing WC/WDM
KEY FINDINGS
Supply Intervention required by 2011
Due to long lead times earliest supply
intervention could only be implemented
by 2014
Shortfall in supply between 2011 and
2013
SCENARIO DESCRIPTION
CCT WC/WDM strategy implemented as well as supply interventions.
Scenario 2
Objective: To determine the impact of implementing the CCT’s WC/WDM
strategy
KEY FINDINGS
Supply intervention required by 2015
Implementation of CCT’s WDM strategy
and programme delays supply intervention
by 4 years
SCENARIO
DESCRIPTION
Scenario 3
CCT WC/WDM strategy and programme implemented as well as additional longer term
WC/WDM interventions and supply interventions.
Objective: To determine the impact of implementing all the WC/WDM interventions
KEY FINDINGS
Implementation of comprehensive WC/WDM could
potentially delay supply intervention until approx.
2019
Comprehensive WC/WDM (100% successful
implementation) can effect a saving of approx 100
million m3 of water per annum by 2019
SCENARIO 7
SCENARIO 8
SCENARIO 9
CCT WC/WDM
strategy
&
Lowest URV
Interventions
CCT WC/WDM
strategy,
Lowest URV
Interventions
&
Ecological
Reserve
CCT WC/WDM
strategy,
Lowest URV
Interventions
&
Possible Climate
Change
ILLUSTRATES IMPACT OF LOWEST URV SELECTION AS WELL AS
IMPACT OF IMPLEMENTING ECOLOGICAL RESERVE AND
POTENTIAL IMPACT OF CLIMATE CHANGE
SCENARIO
DESCRIPTION
CCT WC/WDM strategy implemented, thereafter selection based on URV.
Scenario 7
Objective: To determine the impact of selecting interventions based on lowest URV
KEY FINDINGS
A mix of supply and demand
interventions are available for selection
in order to offset the anticipated shortfall
in supply in 2015.
Net present value of this option is
R1 092 million
17
16
14
12
13
10
9
8
6
7
Scenario 7: CCT WC/WDM strategy implemented, thereafter selection
based on URV
No.
WC/WDM Intervention
Supply Intervention
17
TMG Scheme 1
16
TMG Scheme 2
15
WC/DM: User Education
14
TMG Scheme 3
13
24 Rivers Dam
12
West Coast Aquifers
11
WC/DM: Use of Water Efficient Fittings
10
Cape Flats Aquifer
9
Treated Effluent - Irrig./Ind
8
Voëlvlei Phase 1
7
Upper Wit River Diversion
6
Newlands Aquifer
5
WC/DM: Promotion of private boreholes &
wells
4
WC/DM: Leakage detection and repair
3
WC/DM: Eliminate auto flush urinals
2
WC/DM: Tariffs, metering and credit control
1
CCT WC/WDM 8-year strategy
SCENARIO
Scenario 8
DESCRIPTION
CCT WC/WDM strategy implemented, thereafter selection based on URV with
the ecological Reserve being phased in for existing water resources
Objective: To determine how the implementation of the ecological Reserve will
impact on the selection of interventions
KEY FINDINGS
The yield of the existing water resources decreased
by approx. 46 million m3.
Supply and demand interventions are available
Net present value of this option is R1 263 million.
Cost of implementing additional interventions in order
to offset the anticipated decrease in system yield is
approximately R171 million in today’s terms.
19
18
17
16
14
13
12
10
9
7 8
6
Scenario 8: CCT WC/WDM strategy implemented, thereafter selection based on URV with
the ecological Reserve being phased in for existing water resources
No.
WC/WDM Intervention
Supply Intervention
19
Lourens River Diversion
18
Raise Lower Steenbras Dam
17
TMG Scheme 1
16
TMG Scheme 2
15
WC/DM: User Education
14
TMG Scheme 3
13
24 Rivers Dam
12
West Coast Aquifers
11
WC/DM: Use of Water Efficient Fittings
10
Voëlvlei Phase 1
9
Treated Effluent Irrig./Industrial
8
Cape Flats Aquifer
7
Upper Wit River Diversion
6
Newlands Aquifer
5
WC/DM: Promotion of private bore & well
4
WC/DM: Leakage detection and repair
3
WC/DM: Eliminate auto flush urinals
2
WC/DM: Tariffs, metering and credit control
1
CCT WC/WDM 8-year strategy
SCENARIO
Scenario 9
DESCRIPTION
CCT WC/WDM strategy implemented, thereafter selection based on URV with
the potential for climate change being factored in
Objective: To determine how climate change could impact on the selection of
interventions
KEY FINDINGS
The yield from the existing water
resources and future water resources
was assumed to decrease by approx.
107 million m3.
Supply and demand interventions are
available for selection
Cost of impact is approx. R572 million
22
20
21
19
18
17
16
14
13
10 12
9
8
7
6
Scenario 9: CCT WC/WDM strategy implemented, thereafter selection based on URV with
the potential for climate change being factored in
No.
WC/WDM Intervention
Supply Intervention
Treated Effluent use - dual reticulation
Eerste River Diversion
Lower Wit River Dam
19
Lourens River Diversion
18
Raise Lower Steenbras
17
TMG Scheme 1
16
TMG Scheme 2
15
WC/DM: User Education
14
TMG Scheme 3
13
24 Rivers Dam
12
West Coast Aquifer (Langebaan Road)
11
WC/DM: Use of Water Efficient Fittings
10
Upper Wit River Diversion
9
Voëlvlei Phase 1
8
Treated Effluent use- Irrig./Industrial
7
Cape Flats Aquifer
6
Newlands Aquifer
5
WC/DM: Leakage detection and repair
4
WC/DM: Promotion of private boreholes & wells
3
WC/DM: Eliminate auto flush urinals
2
WC/DM: Tariffs, metering and credit control
1
CCT WC/WDM 8-year strategy
SCENARIO 10(A)
SCENARIO 10(B)
SCENARIO 10(C)
CCT WC/WDM
strategy
&
conservative
Selection of
Interventions
CCT WC/WDM
strategy,
conservative
Selection of
Interventions,
Ecological
Reserve &
Climate Change
All WC/WDM
interventions,
conservative
Selection of
Interventions,
Ecological
Reserve &
Climate Change
”CONSERVATIVE SELECTION” AND IMPACT OF
IMPLEMENTING ECOLOGICAL RESERVE AND
POTENTIAL IMPACT OF CLIMATE CHANGE
Scenario 10 (a) to (c)
“Conservative Selection”
Reasons for omitting specific interventions:
• Additional longer-term WC/WDM interventions
– Equates to approx 50% of the modelled potential WC/WDM
saving
– Uncertainties regarding actual savings achievable
• Newlands Aquifer
– Small yield
– Potential impact on river flow and existing users
• Cape Flats Aquifer
– Perceived O&M concerns of sustainability of operating
wellfield in a relatively high density area
• Upper Wit River Diversion
– Potential difficulties in obtaining environmental approvals
SCENARIO
Scenario
(a)
DESCRIPTION
CCT WC/WDM strategy, thereafter selection based on a conservative
10 selection of interventions
Objective: To determine the impact of selecting a “conservative portfolio”
KEY FINDINGS
Supply interventions would have to be “fast tracked”.
To avoid “fast tacking” WC/WDM would have to be
successfully implemented
Net present value of this option is R1 844 million (this
is in comparison to a NPV of R742 million for Scenario 7, which was
based on least cost selection and not a selection based on
considerations of practicality and sustainability).
9
8
7
6
5
4
3
2
Scenario 10 (a): CCT WC/WDM strategy, thereafter selection based on
a conservative selection of interventions
No.
WC/WDM Intervention
Supply Intervention
9
Treated Effluent use - potable
8
Upper Molenaars (To Berg River
Dam)
7
TMG Scheme 2
6
Lourens River Diversion
5
Raise Lower Steenbras (fast
tracked)
4
Treated Effluent use Irrig./Industrial
3
Voëlvlei Phase 1 (fast tracked)
2
TMG Scheme 1 (fast tracked)
1
CCT WC/WDM 8-year strategy
SCENARIO
Scenario
10 (b)
DESCRIPTION
CCT WC/WDM strategy, thereafter selection based on a conservative selection of
interventions including potential impacts of ecological Reserve and climate change
Objective: To determine how the implementation of the Reserve and the potential for climate
change could impact on the selection of interventions
KEY FINDINGS
Supply interventions would have to be “fast
tracked”.
Net present value of this option is R 4 477
million.
Cost impact of climate change and
implementing the Reserve is approx R 2 633
million
10
9
8
7
6
5
4
3
2
Scenario 10 (b): CCT WC/WDM strategy, thereafter selection based on
a conservative selection of interventions including potential
impacts of ecological Reserve and climate change
No.
WC/WDM Intervention
Supply Intervention
10
Desalination 1 Generic
9
Treated Effluent use - potable
8
Upper Molenaars (To Berg
River Dam)
7
TMG Scheme 2 (fast tracked)
6
Raise Lower Steenbras Dam
(fast tracked)
5
Lourens River Diversion
4
Voëlvlei Phase 1 (fast tracked)
3
Teated Effluent use Irrig./Industrial (fast tracked)
2
TMG Scheme 1 (fast tracked)
1
CCT WC/WDM 8-year strategy
SCENARIO
Scenario
10 (c)
DESCRIPTION
All WC/WDM interventions implemented, thereafter selection based on a conservative
portfolio of interventions, including potential impacts of ecological Reserve and
climate change
Objective:To determine how the implementation of longer term WC/WDM interventions
impacts on Scenario 10(b)
KEY FINDINGS
 Additional WC/WDM interventions delay
supply intervention by 3 years
Net present value of this option is R2 718
million.
Benefit of delaying desalination by
implementing additional WC/WDM
interventions is approx R1 759 million
15
14
13
12
11
10
9
6
Scenario 10 (c): All WC/WDM interventions implemented, thereafter selection
based on a conservative portfolio of interventions, including potential
impacts of ecological Reserve and climate change
No.
WC/WDM Intervention
Supply Intervention
15
Treated Effluent use- potable
14
Upper Molenaars (To Berg River
Dam)
13
Lourens River Diversion
12
TMG Scheme 1
11
TMG Scheme 2
10
Raise Lower Steenbras Dam (fast
tracked)
9
Voëlvlei Phase 1
8
WC/DM: User Education
7
WC/DM: Use of Water Efficient Fittings
6
Treated Effluent - Irrig./Industrial
5
WC/DM: Leakage detection and repair
4
WC/DM: Eliminate auto flush urinals
3
WC/DM: Promotion of private boreholes
& wells
2
WC/DM: Adjustment of water tariffs,
metering and credit control
1
CCT WC/WDM 8-year strategy
SCENARIO 11
Low Water
Requirement Curve
CCT WC/WDM
strategy &
intervention
selection based on
URV
ILLUSTRATES IMPACT OF LOW WATER
REQUIRMENT CURVE
SCENARIO
Scenario
11
DESCRIPTION
The low water demand requirement curve formed the basis of this analysis. CCT
WC/WDM strategy implemented, thereafter selection based on URV
Objective: To determine how the low water requirement curve and the least URV selection
criteria could impact on the selection of interventions
KEY FINDINGS
The Low Water Requirement curve would delay
the next intervention (after the implementation of
the CCT’s WC/WDM strategy) until 2024.
CONCLUSIONS
• Successful implementation of CCT’s WC/WDM 8-year
strategy and programme is essential
• Additional longer-term WC/WDM interventions just as
important
• Groundwater options very important – especially TMG
• Treated effluent use has massive potential. Treated
effluent for potable use may be required as early as 2020
• Desalination of seawater as long term “back-up”
• Feasibility studies should commence on both demand
and supply interventions to ensure reconciliation of supply
and requirement
• A Strategy Committee should be formed to ensure
implementation of the strategy
Interventions Selected for Additional Study
CCT WC/WDM Strategy and
Programme
Michell's Pass Diversion
WC/WDM Adjustment of water tariffs,
metering and credit control
Newlands Aquifer
WC/WDM Eliminate auto flush urinals
Cape Flats Aquifer
WC/WDM Promotion of private
boreholes and wells
West Coast Aquifer Recharge
(Langebaan Road Aquifer)
WC/WDM Leakage detection and
repair
Upper Wit River Diversion
WC/WDM Use of water-efficient
fittings
Raising Steenbras Lower Dam
WC/WDM User education
Lourens River Diversion Scheme
Voëlvlei Phase 1
Treated effluent use
Upper Molenaars Diversion
Strategy Committee
A Strategy Committee should be established with the following
objectives:
•
To ensure that the strategy is relevant and updated,
•
To monitor and co-ordinate the implementation of the
relevant actions identified in the strategy, and
•
To make recommendations on long-term planning
activities required to ensure reconciliation of requirement
and available supply in the WCWSS area
A support group should be established to provide
administrative scientific and technical support to the
Strategy Committee
Representation on Strategy Steering Committee
WC Provincial Government
( 5 REPRESENTATIVES)
Local Authorities
( 5 REPRESENTATIVES)
City of Cape Town: 3 representatives
West Coast District Municipality: 1 representative
Cape Winelands District Municipality: 1 representative
Department of Water Affairs and Forestry
( 9 REPRESENTATIVES)
Regional Office: 3 representatives
Integrated Water Resource Planning: 3 representatives
Water Use Efficiency: 1 representative
Water Resource Infrastructure Branch: 2 representatives
Catchment Management Agencies (when established)
( 2 REPRESENTATIVES)
Berg CMA : 1 representative
Breede-Overberg CMA: 1 representative
Water User Associations
( 2 REPRESENTATIVES)
Berg WUA: 1 representative
Breede-Overberg WUA: 1 representative
23 REPRESENTATIVES
RECOMMENDATIONS
It is recommended that:
• A Strategy Steering Committee be formed to oversee the
implementation of the Strategy
• The CCT and other WSAs should implement their WC/WDM
strategies and programmes
• The CCT and other WSAs should develop integrated
policies on treated effluent use and determine the full future
potential for treated effluent use
• The CCT should continue with the TMG Feasibility Study
and Pilot Project and the Desalination Pilot Plant as these
could be significant future water resources
• The DWAF and the CCT should initiate studies on a number
of interventions to ensure the reconciliation of supply and
requirement
Thank you
ANY QUESTIONS