Two rivers are being made bigger this autumn to help reduce flood risks across 150 square miles of the Somerset Levels and Moors.

The River Sowy-King’s Sedgemoor Drain Enhancements Scheme (Phase One) is being delivered for Somerset Rivers Authority by the Environment Agency.

The rivers’ capacity to carry flood water is being increased by techniques such as creating new banks, raising low spots and reshaping existing banks, and making a new backwater.

The scheme is being partly funded by Growth Deal money from the Heart of the South West Local Enterprise Partnership, as part of a wide-ranging programme of works spread over several years costing £7.2 million.

Protecting against flooding, preserving the Levels

Cllr David Hall, Chair of Somerset Rivers Authority (SRA), said: “The aim of enhancing the capacity of the River Sowy-King’s Sedgemoor Drain system is to give people greater protection against flooding whilst also preserving the special nature and history of the Somerset Levels and Moors.

“Our efforts are focused on improvements that will give flood risk management authorities more flexibility in dealing with the challenges of controlling excess water – which is vital, because nobody can know what surprises the weather will throw at us all.

“A huge amount of work has gone into preparing for this latest phase of works and I thank all SRA partners and contractors for their efforts so far.”

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Increasing the capacity of the Sowy and King’s Sedgemoor Drain

The River Sowy – also known as the Parrett Flood Relief Channel – is used by the Environment Agency to take excess water away from the River Parrett near Aller.

Water flows into the Sowy through Monk’s Leaze Clyse sluice. It goes under the A372 at Beer Wall and down to King’s Sedgemoor Drain (KSD) near Greylake, then it re-joins the Parrett at Dunball, north of Bridgwater.

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From Beer Wall down to the KSD an increase in the Sowy’s capacity of just over 40% is being targeted, for the KSD down to Parchey Bridge the target is just under 60%.

Six structures through which water flows into the KSD are also going to be raised and reinforced, to match the river’s increased capacity.

Dr Rachel Burden, Wessex Flood and Coastal Risk Manager at the Environment Agency, said: “Doing this kind of work on the Somerset Levels and Moors is incredibly complex, because there are so many different factors that must be taken into account and they are all interlinked.

“The project team have shown exceptional determination.

“They’ve used their local knowledge and experience to design improvements that will help to protect people, homes, farms, businesses, land and infrastructure from flooding – and that will tie in with a major plan to keep the Levels as one of the most important places for wildlife in England.”

Other Sowy-KSD system works

Other Sowy-KSD system works in recent years have included:

• creating new river channels under the busy A372 at Beer Wall along with tilting weirs, to help stop the road flooding as it did for weeks in 2014
• installing a new water level control gate near Chedzoy, to help better protect the Chedzoy and Andersea area
• removing obstructive masonry from under Dunball Old Bridge, which carries A38 traffic southbound
• de-silting of bridges to increase channel capacity at Parchey and Dunball
• refurbishing around 100 water level control features at Egypt’s Clyse, Moorlinch and Westmoor

Future Sowy-KSD proposals

The Sowy-KSD project team is also working on SRA-funded plans for further smoothing at Dunball, where the KSD joins the River Parrett through Dunball Sluice. The aim is to increase the maximum flow of water that can be discharged from the KSD to the Parrett estuary, and so reduce flood risks to homes, land and roads.

The Environment Agency is working on plans to refurbish Dunball Sluice itself.

Beyond these two Dunball activities, further phases of the full River Sowy-KSD Enhancements Scheme will be designed and delivered when funding is available, with the aim of further increasing the system’s capacity and thereby further reducing flood risks for local communities.