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?