Flood works on Somerset Levels boost 100 water control features

19th November 2020
SRA

Three projects to reduce local flood risks and improve the environment have been carried out for Somerset Rivers Authority on the Somerset Levels.

The works at Egypt’s Clyse on Othery Rhyne and on the Moorlinch and Westmoor Raised Water Level Areas are part of Somerset Rivers Authority’s overarching plan to enhance the River Sowy-King’s Sedgemoor Drain (KSD) system. (Pictured above: Westmoor).

Enabling this system to carry more floodwater will help to protect 150 square miles, whilst upgrading many water control features boosts habitats of international ecological importance.

Sowy-KSD works are being delivered for Somerset Rivers Authority by the Environment Agency, partly using Growth Deal Funding from the Heart of the South West Local Enterprise Partnership.

“Around 100 separate pieces of work”

A water level control structure with new walkway and fencing, looking out over Westmoor towards distant fields and trees. — Westmoor: the new walkway makes this water level control structure safer and easier to operate, the new fencing helps to keep cattle away from the banks.

A tilting weir that was lowered in its rhyne, seen amidst scaffolding and new walkway poles, with a long view over Westmoor to distant hills. — Westmoor: the tilting weir at the centre of the rhyne (or drainage ditch) was lowered as part of a thorough overhaul of this water level control structure. When it was dismantled, some pieces were found to be held together with tape.

Cllr David Hall, Chair of Somerset Rivers Authority (SRA), said: “The projects at Egypt’s Clyse, Moorlinch and Westmoor have involved around 100 separate pieces of work. They’ve included the installation of new culverts, tilting weirs, headwalls and walkways, and the fitting of trench sheet dams and earth bunds with non-return valves to stop water coming back. Siphons have been jetted and lots of new protective fencing put up.

“Careful attention has been paid to small details. For example, two tilting weirs have been lowered because they were 20 centimetres too high and therefore simply didn’t work very well. Together, all these improvements will help SRA partners to better control local flood risks and they will benefit farmers and wildlife because they allow for better management of water levels at some special places.”

Egypt’s Clyse: “very under-rated”

Of particular importance is the work at Egypt’s Clyse, the water control structure that sits at the confluence of Othery Rhyne and King’s Sedgemoor Drain. Othery Rhyne connects Langacre Rhyne, which runs alongside the River Sowy as a flood relief channel for the River Parrett, and King’s Sedgemoor Drain. Othery Rhyne is used by the Environment Agency to move water between the Langacre and King’s Sedgemoor Drain, for flood (and drought) control and for agricultural and environmental benefits.

A strong twin-walled culvert has replaced a crushed and sinking mess of corrugated iron (see below), and protective steel trench sheets now stand in place of temporary timber piles. Text continues below images.

The squashed and rusted corrugated iron remains of the old Egypt's Clyse culvert replaced for Somerset Rivers Authority in October 2020. — Old Egypt’s Clyse culvert

A new culvert set in a new timber headwall looking from Othery Rhyne across to King's Sedgemoor Drain and the Somerset Levels beyond on a frosty morning, with construction equipment and fencing to both sides. — New Egypt’s Clyse culvert, looking from Othery Rhyne to King’s Sedgemoor Drain.

John Rowlands, of the Environment Agency, said: “Egypt’s Clyse is a very under-rated structure. It plays a really important role in the vastly complicated system of water management on the Levels, because it helps us move water from a wide area from place to place. Its improvement is good news for local homeowners, businesses, farmers and wildlife.”

The works at Egypt’s Clyse and on Moorlinch were done by contractors Land & Water, on Westmoor by contractors Bernard Perry.

Enhancements to the main channels of the Sowy and King’s Sedgemoor Drain are currently expected August to October 2021.