Upgrades to Somerset flood defences won't begin until spring

The Somerset Rivers Authority (SRA) has been working with the Environment Agency (EA) to make numerous improvements to the River Sowy and King’s Sedgemoor Drain (KSD), which divert water from the River Parrett and the River Cary out into the Bristol Channel.

Numerous improvements have been carried out over the last two months, removing silt from the river banks and bridges to increase capacity and thereby ensure water can flow off the moors more quickly.

The SRA board stated in June that it hoped some of the improvements would be completed before the end of the calendar year, while others would have to wait until mid-2025 to see the light of day.

Three months on, the board heard in Bridgwater on Friday morning (September 20) that each element of the project will now begin in the spring or summer of 2025 to allow “surety of delivery and costs”.

The two outstanding elements of the current programme (dubbed ‘phase one’) concern improvements to the Chedzoy tilting weir and the Back Ditch outfall, which both lie between Bridgwater and the Polden Hills.

The Chedzoy tilting weir. (Image: Daniel Mumby)

Both structures are maintained by the Parrett Internal Drainage Board (IDB) and are located on land owned by its vice-chairman, Tony Bradford.

Around £150,000 was earmarked for these improvements, which will reduce the amount of agricultural land affected by flooding in this section of the Somerset Levels and Moors, and thereby reduce the amount of lost income for local farmers.

The EA originally intended for work to begin in September 2023, but postponed this to mid-January – only to find it was unable to access the sites.

This prompted criticism from both Mr Bradford and the SRA board, which stated in January that it was “not walking away from it” and was “determined to get this done”.

Caroline Murray and Iain Sturdy from the Somerset Drainage Board Consortium (SDBC) told the SRA board on Friday (September 20) that they were recommending the outright replacement of both structures rather than refurbishing the existing parts.

They admitted, however, that this would cost £250,000 – up to £100,000 more – and could not begin until March 2025 at the earliest.

They said in their written report: “The tendering process commenced at the beginning of August and we are in the process of finalising the contract costs with the chosen contractor, having issued a final set of construction drawings.

“On the basis of the tender returns, the IDB recommends full replacement of both Back Ditch and Chedzoy tilting weir with a projected budget of £250,000.

“We had hoped to be able to push for delivery this year, but on a review of the tender programmes submitted for these works, the costs and the availability of suitable contractors, the IDB would recommend a delay until the spring for surety of delivery and costs.

“If this can be agreed, then delivery of the works could proceed in March or April 2025 with the IDB’s chosen contractor.”

In addition to upgrading these two structures, the EA has been looking at how the left back of the KSD can be raised, to increase the capacity of the artificial river and thereby allow larger volumes of water to be carried downstream.

Up to 1.8 kilometres (just over a mile) of the river will be raised, focussing on the stretch between Chedzoy and Westonzoyland.

Ms Murray and Mr Sturdy said that “detailed ground investigations” had been carried out in early-July to ensure the scheme was viable.

They said in their report: “An initial overview of the environmental, archaeological and physical constraints along this short section of the KSD has enabled many of the constraints that had to be addressed as part of the wider project to be screened out.

“The IDB cannot commit at this stage to being the SRA’s delivery partner for any final bank-raising works.

“However, if a project completion plan can be agreed, delivery of the works could proceed in July 2025.”

The board voted to note the report and release the £250,000 needed to ensure the Back Ditch and Chedzoy tilting weir upgrades could proceed in the spring.

A further update on these projects is expected to come before the board when it reconvenes in Shepton Mallet on January 24.