More news...

Jul 6, 2018
Category: Drought
Posted by: Kathryn

With this hot weather our water use goes up; this leaves less water available for the Chess.

May 3, 2018
Category: Abstraction
Posted by: Kathryn

With an ever-growing demand for drinking water and increasingly extreme weather events, how do we get the water we need without causing even more harm to our rivers?

May 2, 2018
Category: Drought
Posted by: Kathryn

Our riverfly monitors are back out in the centre of Chesham checking for life in the Chess now that flow has returned.

Mar 24, 2018
Category: HS2
Posted by: Kathryn

A public meeting with HS2 and the Environment Agency looked at the risks posed by tunnelling to the groundwater and rivers of the Chess and Misbourne Valleys.

Latest News

Dredging The Chess; What's the Point?

Jan 23, 2015

Category: Flooding
Posted by: Kathryn

The Chess at Scotsbridge

Above: The River Chess at Scotsbridge

Last year the River Chess flooded houses close to Scotsbridge Mill. Now, the Environment Agency is starting a project to dredge the river at this location in the hope of reducing the flood risk. This is an expensive and invasive procedure which we feel will do little to mitigate flood risk.

The river is trying to find its own natural route around the mill and without any interference from us eventually it will. That would mean the mill leat would possibly eventually dry up. The perched channel leading up to the mill, part of the Chess Valley Walk, would also eventually dry up.

From our understanding the flooding in the Scotsbridge Mill area last winter was caused by a number of issues coming together at the same time. It was a combination of already eroded and weakened banks, high flows and material blocking a trash screen on the side channel. The high flows caused the main river to breach its banks at the points where the bank had been eroded and weakened. The water filled the side channel which then became blocked. The flow backed up quickly and found its way into houses along side Park Road. 

Dredging the channel above the mill will not answer any of these problems.We believe that the short term solution would be to lower the weir at the mill, or the side sluices. This would lower water levels above the mill and reduce the chances of the banks being breached. 

The banks need to be repaired, which is a long-term reoccurring problem. The sluices in the mill leat need to made functional again and should be lowered at times of high flow. The side stream culverts needs to be kept clear of trash and culverts removed or widened. Once this has been done, somebody needs to be responsible for monitoring levels and taking appropriate action. This is a high maintenance solution. 

The other alternative is to encourage the river to find its natural route and it will then manage itself, significantly reducing flood risk. This would require landowner support as it will significantly alter land use. This does also have consequences for water flow in the mill leat, the mill and the perched channel leading up to the mill; this will dry up. This changes the mill significantly and might cause structural integrity issues for the building. There might also be historical, heritage issues.

We are concerned that the dredging activity does little to resolve the problems on this stretch of river. We cannot see that this activity on its own will reduce water levels and therefore does little to mitigate flood risk. We would argue that the money, all £300,000 of it, could have been better spent on coming up with a long-term sustainable solution.