River restoration to reduce flooding risk

Work started this week (Monday January 22) on restoration to a tributary of the River Chess to reduce flood risk in Chesham Old Town, create a more natural aqua-scape, and consign to history a century-oldconcrete weir.

The scheme is the brainchild ofBuckinghamshire County Council’s Flood Management Team, working with the Chilterns Chalk Streams Project, theHundridge Estate and Chesham 1879 Lawn Tennis and Squash Club through whose land the river flows.

It aims to create more capacity, achieve a steadier flow, and stop water backing up to cause flooding. It should be finished by the beginning of February.

The plan is to replace a shallow 100 metre channel with a deeper winding channel using pre-planted coir rolls and chestnut clefts backfilled with river sediment and wood chippings.

And one of two weirs, thought to have been built around 100 years ago to support Chesham’s famous watercress production, will be demolished to allow gentle regrading of the river bed, and prevent localised flooding.

Pruning to a belt of trees, which started this week along the whole 200 metre reach, will increase the amount of light to the new channel, and dead wood is being removed where it endangers people or property.

This project, costing around £20,000 and using local suppliers, follows an investigation by the Flood Management Team after the 2014 floods, which waterlogged neighbours’ homes that back on to the river. Around 100 properties in the area are at risk of flooding.

Chalk Streams Project Officer Allen Beechey said the 10-mile long Chess is one of several chalk streams that rise in the Chilterns. Chalk streams, which flow only when ground water levels rise, are a globally rare habitat, and England has the majority of them.

Bill Chapple OBE, County Council Cabinet Member for Planning and Environment, said: “By restoring this section of the River Chess, we’ll be returning it to a more natural state, which will allow the natural chalk stream processes to re-create habitat.

“I’m very pleased our team have thought so carefully and creatively. They’re not only reducing a flooding risk to residents and businesses in the old town, but alsoworking with local experts to re-create a habitat lost long ago, and which will be good for restoring flora and fauna to this reach of the Chess, and enhancing our local environment.”