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Water Resources for Hertfordshire
Alex Back Hydrologist
28th October 2010
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Who are Veolia Water?
CentralEast
South East
3 Water Companies, and have been part of an international water supply company since 1989
Water Only
Population 3.5 million
Supply 900 Mld Average and 1210 Mld at Peak
Mains 16,172 km
We have duty to meet customer demand
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Issues for Water Supply in Hertfordshire
New towns were built in the 50s and 60s; Welwyn Garden City, Hatfield, Roydon, Stevenage and Letchworth
Little consideration was given to the effect of these new towns on the environment when they were built and local groundwater was developed
Groundwater abstraction affects river flows in Hertfordshire especially during times of low groundwater levels or drought
Groundwater sources are being used to their full capacity during times of peak demand providing local water for local people and constitutes 60% of our supply
Groundwater is the best quality and lowest cost source of water in Hertfordshire and helps to keep customer bills as low as possible
We also import 10% of our water from Anglian Water’s reservoir at Grafham but this is expensive and of lower quality and the remaining 30% comes from the river Thames
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Future housing growth and population growth
It is predicted that 200,000 new people will move into the area by 2040
This has been allowed for in our WRMP by adopting a twin track approach of new resources and demand management, but the majority of these will not be required before 2035
EoE plan no longer exists, and we now have to seek the latest situation on housing growth from the Local Authorities
Dry Year Critical Period BalanceFinal Planning
900.00
950.00
1000.00
1050.00
1100.00
1150.00
1200.00
1250.00
1300.00
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
Financial Year Ending
Mil
lio
n l
itre
s p
er D
ay
Normal Year Demand Dry Year Demand Demand Plus Headroom Final Planning WAFU
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Environmental Issues
Chalk rivers are recognised as a rare and valuable habitat
Low flows (following winter droughts) a major concern
Flooding and climate change are also significant impacts
We have been working with the EA since 1990 and 3 of the original 1991 ALF projects on the Hiz, Misbourne and Ver were implemented in AMP2 (1995-2000),
Major NEP programme, based on RSA work (2000-2015) currently investigating Misbourne, Ver, Colne and Rib
Sustainability changes already notified for post AMP5 (2015+)
More to come, and working with the EA to identify these, but it is difficult and expensive to replace water
Cost – benefit analysis is difficult and in surveys, our customers showed a low preference to pay for environmental issues
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Pollution Risks
Major issue, many sources impacted by pollution
Nitrates, pesticides, hydrocarbons, legacy landfill and industrial sources, turbidity & microbiological
Unconfined Chalk, provides limited protection and rapid flows means threat of pollution constant
To protect the quality of the water we supply, pollution is normally managed by installing treatment, blending or sometimes abandonment/replacement of source
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Pollution Risks
Investigation and removal of source of pollution, especially in groundwater is very difficult and expensive, legally complicated and subject to long time delays the “polluter pays” principal is not often the end result
We work hard to prevent pollution and undertake catchment surveys and risk assessments to identify potential threats
These feed into Drinking Water Safety Plans and catchment management activities
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Thank you for your attention
Any questions?
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