£10million scheme cuts flood risks for Somerset Levels and Moors

26th September 2025
SRA

Works are nearing completion on a major £10million Somerset Rivers Authority (SRA) scheme to reduce flood risks for a large part of the Somerset Levels and Moors.

1.22miles (1.96kilometres) of the left bank of King’s Sedgemoor Drain (KSD) are being raised by the Parrett Internal Drainage Board (IDB), working as a partner in the SRA.

The bank-raising is the final part of a scheme that will enable nearly 25% more flood water to flow safely in channels through the connected River Sowy – KSD system. This system runs for 13.5 miles (22km) from Monk’s Leaze Clyse sluice at Combe near Langport down to Dunball Sluice north of Bridgwater.

Creating extra Sowy-KSD capacity helps to protect homes, businesses, land and roads across 150 square miles, especially around Langport and upstream of Langport.

King’s Sedgemoor Drain bank raising. Surveyors check that work is being done according to the scheme’s design.

Extra Sowy-KSD capacity helps because the Sowy is a River Parrett flood relief channel (created in 1969-72).

The more water can safely flow from the Parrett into the Sowy, the less water there is in the Parrett.

The less water there is in the Parrett, the more water can be pumped off the Somerset Levels and Moors into the Parrett.

The Sowy can also now take more water before storms even start.

All this helps to reduce flood risks and damages.

Councillor Mike Stanton, Chair of Somerset Rivers Authority, by King’s Sedgemoor Drain.

Councillor Mike Stanton, Chair of Somerset Rivers Authority, said: “During the floods of 2013-14, which are estimated to have cost Somerset nearly £150 million, the single emergency action identified to make the biggest difference in reducing those floods’ depth and duration, was making more use of the River Sowy.

“That’s why, bit by bit over several years, partners in the SRA have since been working together to improve the Sowy-KSD system.

“The various things we’ve done between us are not a cure-all but they will make an important difference – especially because they tie in with more than £30million worth of other major flood risk reduction schemes that SRA partners have been involved with.

“Through our Sowy-KSD works, we’ve also helped to enhance the special environments of the Somerset Levels and Moors, which we know are precious for wildlife and valued by many people.

“So I’m very pleased to see this final stretch of KSD bank-raising being done and I’m grateful to all those who have helped.”

SRA Vice-Chair Tony Bradford (in orange hi-vis jacket) being interviewed by Ross Pollard of BBC Points West, with SRA Chair Cllr Mike Stanton looking on.

Tony Bradford, Chair of the Parrett IDB and SRA vice-chair, said: “I’ve been involved with the SRA since it started more than 10 years ago. Throughout that whole time, because I’ve seen how bad flooding can be for people, people that I know and many more, I’ve been pressing for us to get our rivers sorted out.

“A lot of good work for this Sowy-KSD scheme was previously done by the Environment Agency. In the Parrett IDB, we’ve put some serious time and effort into following on from them and we’re now getting this scheme done.

“We’re in the SRA to reduce flooding – that’s what we’re doing here, and it makes me very happy to see it.”

The Parrett IDB has been working on this final section of KSD bank raising with civil engineering consultants Calm Engineering and contractors WM Longreach.

How this KSD bank raising fits into the bigger picture

Previous Sowy-KSD activities led by the Environment Agency, working as a partner in the SRA, included:

bank raising along the upper Sowy from Monk’s Leaze Clyse down to Beer Wall near Othery
bank-raising along the lower Sowy from Beer Wall down to its confluence with the KSD near Greylake
previous stretches of bank-raising along the KSD
desilting of bridges to increase capacity at Parchey and Dunball
upgrading four river outfalls
replacing or refurbishing around 100 water level management structures at Westmoor, Moorlinch and Egypt’s Clyse
creating a backwater, three two-stage channels and three embayments (shallower riverside shelves)

The Parrett IDB also recently upgraded two river outfalls, Back Ditch and Chedzoy Tilting Weir.

The newly-improved Chedzoy Tilting Weir being viewed by SRA Board member Cllr Nick O’Donnell (left) and SRA Manager David Mitchell.

Benefit of all Sowy-KSD activities

The effect of all these measures is that the in-channel capacity of the Sowy-KSD is being increased by 24.2%, from just below 17 cubic metres per second (called cumecs for short) to 21.

This equates to an extra 14,760 cumecs per hour – or around 354,000 per day. (To help visualise the benefits of this in simple domestic terms, the volume of an average two-storey house with two bedrooms is around 200-250 cubic metres).

Associated flood risk reduction schemes since 2014

In its turn, this increased Sowy-KSD in-channel capacity is part of a bigger programme of flood risk reduction schemes since 2014. These have included:

raising the A372 at Beer Wall near Othery and installing four massive new culverts under that raised road (delivered by Somerset County Council, cost £4.1million, funded by the Department for Transport)
creating two new river channels to flow under the raised road at Beer Wall (Environment Agency, £4.35million, funded by the SRA including part of its share of Growth Deal funding from the Heart of the South West Local Enterprise Partnership – HotSWLEP)
pioneer dredging of 5 miles (8km) of the rivers Parrett and Tone in 2014 (Environment Agency, £6million funded by the Department for Environment, Food & Rural Affairs)
SRA-funded pioneer dredging and maintenance dredging along the River Parrett since 2015, including dredging the River Parrett between Oath and Burrowbridge (done by the Environment Agency and the Parrett IDB, £6.4million, including £2.222million from HotSWLEP)
improving Chedzoy Flap, which controls the confluence of the Penzoy system (including Chedzoy New Cut) and the KSD, to better protect farmland around Chedzoy and Andersea (Environment Agency)
removing obstructive masonry from under Dunball Old Bridge, which carries A38 traffic southbound (Somerset County Council, £359,000)
refurbishing Dunball Sluice (Environment Agency, £9.7million, with a contribution of £650,000 from the SRA)

Cllr Mike Stanton said: “The works outlined here are only part of what’s been done since 2014 to reduce the risks and impacts of flooding in Somerset. Many different people and organisations have doggedly pursued the aim of making Somerset a safer and better place.

“I am proud of the significant role that Somerset Rivers Authority as a partnership has played in this. We are looking forward to doing more across Somerset. But let’s be clear: this is a man-made landscape which used to be marshes. Nobody can guarantee there will not be further flooding in this time of increased rainfall from climate change.”