Transcript The Regional Water Supply Strategy

The Regional
Water Supply
Strategy
Securing water supply for the
townships of Quirindi, Werris
Creek and Willow Tree
The Current Situation
 Liverpool Plains Shire Council LGA
 Within the Namoi Valley, 470 kms NW of Sydney
 Services townships of Quirindi, Werris Creek,
Wallabadah, Willow Tree, Spring Ridge, Premer,
Blackville and Caroona
 Area of 5005 square kms and a combined
population of 8,000
 Business and employment is
dominated by agriculture
and mining.
The Current Situation
 Current Water Supply
 Quirindi and Willow Tree supplied from Upper
Namoi Alluvial Groundwater Aquifer via a simple
treatment plant.
 Werris Creek is supplied from Quipolly Dam via a
water treatment plant in the town.
 Each township has a single source of water only
 Water consumption in 2012:
 Quirindi – 580 ML/annum
 Werris Creek – 250 ML/annum
 Willow Tree – 55 ML/annum
The Current Situation
 Constraints of Current Water Supply – a dichotomy
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Single source = no backup in the event of contamination, scarcity.
Aquifers are dependent on short term stream flows and favourable climate.
Aquifer groundwater levels in long term decline – not sustainable (McNeilage, 2006)
In 2006-07, township of Willow Tree almost ran dry (Level 7 restrictions were imposed).
Water supply in Wallabadah failed requiring emergency cartage.
 In 2009, Werris Creek Lvl 4 restrictions – insufficient WTP capacity.
Quipolly Dam has enough capacity to supply all townships,
but is only connected to Werris Creek.
Climate Change
 Predicted Impact on Water Security
 Water availability is predicted to decrease by 5%
by 2030 (CSIRO Sustainable Yields Report for the
Namoi Valley )
 Average annual temperature will go up by 3o C
by 2050
 Rainfall to become more variable (longer
droughts, more intense periods of rainfall)
 Average runoff predicted to decrease
by 7% by 2030. Likely to intensify
after 2030.
Risks Assessed
 High to extreme risks associated with short and long term water supply security
during dry periods
 High to extreme risks associated with capacity of water treatment and storage
infrastructure. Pressures from growth being realised already.
 High to extreme risk to supply security caused by reliance on a single water
source. No options if source is contaminated or depleted.
 High to extreme risk associated with reliability of water supply infrastructure.
External impacts such as electricity supply interruptions expected to increase.
 High risk of climate change impacts
 Significant structural pressures – particularly in the next 5 years
 Infrastructure funding constraints. Revenue base insufficient to meet immediate
funding requirements.
 Low adaptive capacity to water security risks.
Opportunity to Grow & Improve
 Mining related growth – indirect impacts
 Independent social impact reviews determine 1450 -1730
new jobs in the Liverpool Plains and Gunnedah LGAs
 BHP Billiton estimates 400-500 new employees in Caroona
Mine. Shenhua Watermark mine similar at Breeza.
 Even more during construction phase.
 Multiplier effect from supporting industries.
MAC Worker Village – DA approved for miners village equivalent to 525 dwellings (1500 miners) in Werris
Creek, effectively doubling the population of the
township
Water – Essential to Growth
 Issues with water supply in the future
 WSAA specifies that to minimise risk of loss of supply, a minimum of 24 hours water
storage should exist. Ratios are relative to this standard.
Table 1
Reservoir and WTP capacity constraints in LPSC, 2015 and 2030, mining step change
population growth
2014/15 forecast
Town
Existing
Storage
(kL)
Quirindi
9,250
Werris
Creek
5,500
WTP
capacity
(kL/day)
1,360
Peak Day
Demand
(kL)
Storage
days
ratio
5,057
1.83
2,199
2.50
2030 forecast
WTP
capacity
ratio
0.62
Peak Day
demand
(kL)
Storage
days
ratio
5,993
1.54
2,548
2.16
Werris Creek WTP will not have sufficient
capacity in 2015/16 and will be able to supply
only half the demand in 2030
WTP
capacity
ratio
0.53
Water – Essential to Growth
 Issues with water supply to 2030
 Willow Tree has less than 1 day’s storage at 2014/15 and will have 15 hours of
storage at 2030. No room for system failure or power outage.
 System lacks the capacity to deal with water source contamination events
 System lacks capacity to deal with a growing incidence of extreme weather
events:
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Insufficient water treatment capacity
No diversification of supply
No redundancy of supply
Inadequate storage capacity in the system
The Regional Water Supply Strategy
 Works completed
 New 5ML reservoir in Quirindi , Safety upgrade
and storage augmentation of Quipolly Dam
 Component 1
 New 10 ML/day Water Treatment Plant, raw
water pump station and treated water pump
station 150kW, new pipeline to Werris Creek
 New main from WTP to Quirindi, alterations to
pump equipment Quirindi
 Component 2
 New main supplying Willow Tree from Quirindi,
pump station for water transfers regionally and
a new balance tank at Willow Tree
The Regional Water Supply Strategy
 Benefits of the Regional Water Supply Strategy
 An integrated water supply will provide 2 sources of water
(surface water and groundwater) to all townships.
 A new water treatment plant will provide adequate supply
to facilitate growth in Werris Creek to 2050. Expandable
beyond 2050.
 A new water treatment plant will include capability to
manage water quality events from Quipolly Dam, improving
water supply security.
 Address water security issues and reservoir capacity issues
to 2050 at Willow Tree.
 Provide more redundancy for system failures and extreme
weather events.
 Expandable to other supplies if required
The Regional Water Supply Strategy
 Strategic Roadmap - Development
We are
here
The Regional Water Supply Strategy
 Capital Cost
Stage No.
Completed
Activity
Capital cost ($million)
5 ML reservoir in Quirindi, safety upgrade and augmentation of
Quipolly Dam (5.2GL to 8GL)
$7.3m
Complete
Component 1
New 10 ML/day WTP raw water pump station augmentation and
treated water pump station 150kW, new main to Werris Creek,
New main from WTP to Quirindi, pump station alterations in Qdi
$24.8m
Component 2
New main supplying Willow Tree from Quirindi, pump station for
water transfers regionally and a new balance tank at Willow Tree
$2.4m
RWSS Capital
Cost
Components 1 and 2 (remaining stages)
Cost estimates include allowance for contingencies and engineering ( in 2013/14
dollars)
$27.2m
Regional Water Supply Strategy –
Merit Criteria Assessed
 Value for money.
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Levelised cost $0.32/kL (based on whole of life Capex and Opex in 2013/14 $’s
@ 7% discount rate)
Significant contribution to water security.
Technically feasible and low risk operation.
No negative environmental or social impacts.
Fosters regional growth & prosperity.
Improved level of service to consumers.
Project delivery timeline
Work Package
Task Duration
Servicing Strategies
6 weeks (complete)
Concept Design
22 weeks (complete)
Procurement Strategy
4 weeks
Design and Construct
78 weeks
Total
110 weeks (25%
completed already)