New water abstraction from River Chess in Chesham sparks fears of more drying events

A secret agreement to abstract of millions of litres of water from the River Chess in Chesham has been agreed between the Environment Agency (EA) and Affinity Water.

Both parties have said that pumping water out of Buckinghamshire’s precious chalk aquifer is necessary to reduce the risk of flooding.

However, environmental groups have warned that resuming water abstraction from the upper Chess could be ‘disastrous’ for the globally rare chalk stream and the wildlife which depend upon it.

The EA said it began talks with Affinity about the abstraction of water from the former pumping station on Alma Road in Chesham in April last year.

An agreement set to last until 2029 was reached in July this year, meaning that around 62 mega-litres (62 million litres) of water will be abstracted per month.

An average 2 mega-litres of water a day will be extracted during periods of normal or low groundwater levels and up to 7 mega-litres a day during periods of high groundwater levels.

The abstracted water will be pumped into the public water supply after it has been treated and quality-checked. It will likely supply Chesham town and potentially its surroundings.

The EA claimed that modelling of groundwater had shown that stopping public water supply abstraction at the top of the Chess catchment ‘suggested’ an increase in groundwater levels, which ‘could cause an increase in flooding’.

The public body told the Local Democracy Reporting Service that it needed to carry out further modelling to fully understand the extent of ‘groundwater and river flood risks’ and that ‘there continues to be an overall net reduction in abstraction’.

A spokesperson said: “We have asked Affinity Water to recommence partial abstraction of the River Chess as although too little water is harmful to the ecology of the river Chess, too much water could increase flood risk.

“We need to find solutions where we protect the river, whilst also protecting people’s homes and businesses from flooding.

“Reducing or stopping abstractions can have unintended consequences, such as an increase groundwater or river flood risk.”

The spokesperson added that it needed a daily abstraction from the Chesham pumping station until its studies were complete.

Affinity said it was fully complying with the ‘statutory S20 agreement’ issued by the EA.

The water firm decommissioned the pumping stations at Alma Road and Chartridge in 2020, which according to the River Chess Association, signalled that abstraction from the Chess would cease.

The association said it was therefore ‘surprised’ to have been notified that Affinity had accepted the EA’s request to resume pumping millions of litres of water out of the ground in Chesham.

It claims that there is no evidence to show that there is any meaningful risk of fluvial flooding from reducing abstraction and also says it was not consulted on the EA and Affinity’s plans.

A spokesperson for the environmental group said: “It was a shame as our challenges would have saved the Environment Agency from this embarrassing, ill-advised mistake.

“It was also a kick in the teeth for all our volunteers who believed they were working in partnership with a common goal to improve the River Chess.”

One of the group’s volunteers who has been collecting flow data from the Chess since 2016 said the news of the abstraction had come ‘out of the blue’.

Part of the fear surrounding the looming return of abstraction is that drying events in the upper Chess like those seen from 2010 to 2019 may also return.

Environmental groups are concerned that this could threaten precious wildlife in and around the Chess and risk overturning some of the area’s recent ecological gains.

These include the return of water voles to the centre of Chesham, the presence of otters in the town, mayfly coming back to Chesham Moor, recordings of stonefly for the first time in 15 years and brown trout breeding upstream of Cannons Mill.

A spokesperson for the charity Wild Fish said: “This is a massive backward step for the River Chess and its wildlife.

“Protecting headwater chalk streams flows are essential to protect their ecology and improve their resilience to climate change.

“This again shows the failure of the regulator and water company to develop the necessary water supply infrastructure to protect the river.”