Thames Water has reduced the amount of water it takes from underground sources near a High Wycombe chalk stream by more than seven million litres per day – equal to that used by around 20,000 homes – to help the waterway sustain wildlife.

For more than 100 years, water has been pumped from deep underground boreholes at Pann Mill near the River Wye to meet the needs of thousands of homes and businesses across the Wycombe area.

Investigations into the impact of such abstraction have however shown it can adversely affect the health of some chalk streams, meaning they are no longer a sustainable source of water.

Following one of these investigations Thames Water has reduced the amount of water it pumps from the Pann Mill boreholes to leave more in the ground to support flows in the Wye.

Instead more can now be abstracted from boreholes in Medmenham, close to the banks of the River Thames and therefore less environmentally sensitive than chalk streams like the Wye.

The company is also reminding its customers to make every drop count to help protect all watercourses, enable it to further reduce abstractions from chalk streams and ensure there’s enough water for future generations. In the Chilterns average daily water use is around 173 litres per person. This is 30 litres more than the national average and much higher than in countries like Germany, where residents use just 121 litres each, per day.

Andrew Tucker, water efficiency manager at Thames Water, said:

“Every drop of water we all use comes from the environment so the less we use the more is left in rivers and the underground aquifers that feed them, to sustain wildlife. We’re working hard to reduce the amount of water we lose to leaks and reduced this by 15 per cent last year, but while we continue to do our bit to leave more in the ground to support chalk streams, we also need everyone to use a bit less. It’s vital that at a time when we’re seeing the impacts of climate change and more people move into our area, there’s enough water for everyone.”

Mike Overall, chairman of the Revive the Wye Partnership added:

"Since we formed the Revive the Wye Partnership (RTW) in 2008, the many improvements made to the River Wye have increased the quality of the chalk stream, its wildlife and its river margins. RTW volunteers have played a major role in these restoration achievements. Thames Water's decision to reduce the amount of water extraction at Pann Mill will help sustain those improvements and aid further enhancements in the face of high and increasing demands for domestic water."

Over the next five years Thames Water will further reduce the amount of water it takes from chalk streams, like the Wye to help protect the environment. This includes the closure of a groundwater source at Hawridge near Chesham, Bucks, by the end of 2024.

Tom Entwistle, a specialist at the Environment Agency added:

“The investigation of and subsequent reduction in abstraction at Pann Mill were part of the Environment Agency’s Restoring Sustainable Abstraction programme, and a great example of work to reduce unsustainable abstraction pressures on sensitive rivers such as chalk streams.

“This is one of a number of reduced abstractions in the area that will contribute to improving the quality of local chalk streams. Increasing the sustainability of abstraction is key to supporting the ecology and natural resilience of our watercourses and groundwater, particularly in the face of increasing demands and changing climate.”