Improvements planned for key Somerset river following new flood modelling
The Somerset Rivers Authority have produced new modelling which could help with future planning - a decade on from the first alarm being raised from the 2013/14 floods
Numerous improvements could be made to one of Somerset’s main rivers in the coming years thanks to new modelling undertaken by the Somerset Rivers Authority (SRA).
The SRA was created in 2015, in the aftermath of the disastrous floods of 2013/14, bringing together different partners to deliver additional flood prevention schemes on top of those carried out by Somerset Council or the Environment Agency (EA).
Since its foundation, the SRA has overseen numerous improvements to the River Parrett and River Tone catchment areas, including several rounds of dredging and upgrades to the River Sowy and King’s Sedgemoor Drain.
But enhancing the River Brue has proved perennially problematic, with £279,000 of funding going unspent in July 2021 after the details of an improvement scheme could not be agreed.
The SRA has now completed detailed modelling work, showing which parts of the catchment area are most likely to be hit by flooding – making it easier to identify and prioritise sites where improvements could be made.
The River Brue begins in Brewham near Bruton and flows over the Somerset Levels, separating Glastonbury and Street, before reaching the sea at Highbridge.
Many of the lower reaches of the river are very close to sea level, making large parts of the catchment prone to flooding – especially following periods of heavy rain, such as those seen in September 2023.
At Highbridge, there is significant building along either side of the river – including the Brue Farm housing development, the Walrow industrial estate and the town’s railway station (which could soon be connected to Brue Farm by a new bridge).
Highbridge, Burnham-on-Sea and the surrounding villages are protected by the Highbridge Clyce, which prevents saltwater from flooding upstream and bursting the river’s banks during high tides.
But efforts to protect other parts of the catchment have been stymied by several factors – including protected species, agricultural practices and the need to protect and improve water quality.
The Axe Brue Internal Drainage Board originally planned to dredge key sections of the river using £279,000 provided to the SRA by the Heart of the South West Local Enterprise Partnership (LEP).
This money was handed back to the SRA in July 2021 after the drainage board was unable to secure a viable dredging scheme which would complement the EA’s existing maintenance programme.
Following this, the SRA was commissioned to carry out new modelling of the Brue catchment area to assess flood risk – work which was formally presented at its most recent board meeting in Bridgwater on January 19.
A number of models have been produced at a cost of £91,170 – including a ‘one in 100 years’ event similar to the 2013/14 floods and a ‘one in two years’ event (estimating more localised flooding).
John Rowlands stated in his written report: “The outcome of this work is a model which can be used to provide the scientific justification to support implementation of future schemes in the lowland Brue catchment.
“This model is now able to be shared with project partners. This model is capable of being used to assess the impacts of any interventions in the area on high flows of water and flood risk.
“Due to the way the model has been developed to focus on high flows, it is not able to represent low flows, or give information on any of the smaller rhynes, but all of the main rivers are represented along with the moor areas.
“It is expected that our partners will now look to use this model in their projects to assess the impacts of any proposals they are considering.”
The modelling can be used to test various projects designed to increase the volume of water which can be carried downstream, or to improve the amount of water which can be safely stored on the moors during heavy rainfall.
Mr Rowlands said the Somerset Wildlife Trust (SWT) had already expressed some interest in improving the river, and some payments could be made to farmers to improve the land they own along the river (known as riparian improvements).
While dredging and desilting could still be carried out, he warned it would be “extremely challenging to deliver that in this environment.”
SRA vice-chairman Tony Bradford, who sits on the Parrett Internal Drainage Board, said that he wanted progress to be made as soon as possible – including trimming back trees and vegetation which could block the river.
He said: “All the work the SRA has undertaken has been on the Parrett or Tone catchment – nothing’s been done on the Brue.
“The state of the trees on the Brue – they’re shaking hands with each other. Why haven’t we done a maintenance vegetation clearance?
“We could see some action on that immediately – we’ve been kicking this down the road for years.
“It’s urgent that we go and do this work. If you sit on the Brue stone at Highbridge the bridge on the A38 Huntspill Road and look both ways, you struggle to see the water for the trees.”
Councillor Ros Wyke, Somerset Council’s portfolio holder for economic development, planning and assets, said that the upper Brue catchment should not be neglected when it came to flood prevention.
Her Mendip West division includes the River Sheppey, which flows into the Brue north of the small village of Meare.
She said: “We are seeking an awful lot of flooding on the main roads through this area. We need to do work on the upper reaches of the Brue and the Mendip Hills.”
Mark Main, who serves on Alford Parish Council, said that the model should be reviewed to take account of recent flooding in the villages around Castle Cary.
He said: “The model is already out of date as it does not take into account the January 2024 flooding in Lovington.
“If the model does not take into account the 400-plus housing approved in Castle Cary that are within the Brue catchment, and as-yet only partially built, if will be further out of date very shortly.”
In addition to the new homes being constructed in Castle Cary, around 1,400 new homes could soon be delivered within the River Brue catchment area through fallowing agricultural land at Prestleigh Farm near Shepton Mallet.
The council announced the scheme, being delivered by the BNG Partnership, in July 2023 as part of a wider set of initiatives designed to solve the ongoing phosphates crisis, which is holding up around 18,000 new homes across Somerset.
The government announced a further £9.6m of funding before Christmas 2023 to expand the council’s phosphate credits systems, allowing developers to offset the impact of new homes by purchasing mitigation elsewhere in the same catchment.
The council has yet to confirm precisely how many homes these schemes will unlock and in which exact locations within the Brue catchment area.
Further updates on efforts to improve the Brue will come before the SRA board at a later date.