Bedburn Fish Easement
On Bedburn Beck the old stone weir in Hamsterley Forest had been a challenge for fish to pass. The weir itself was becoming structurally unsound so a Defra River Improvement Fund project was designed to incorporate a series of rock pools whilst reinforcing the existing structure. Fish are now able to pass the weir even in low flows as the water has been directed down through new pools.
The Bedburn Beck flows down from the edge of Teesdale through Hamsterley Forest and out into the main River Wear, close to Witton-le-Wear. The tributary is a crucial nursery for a range of fish species, so much so that local anglers and conservationists have bought up the fishing rights to provide wildlife with a safe haven.
Although the beck provides some of the best spawning habitat in the catchment, fish populations have been much lower than expected, owing to barriers that restrict movement between the main river and the spawning grounds. These include an Environment Agency gauging station in the lower reaches, used to monitor river levels and assess flood risk, and a weir originally constructed to divert water to a mill in Bedburn village, which now provides water for a wildlife pond managed by the environmentalist Professor David Bellamy.
The weir was still fulfilling its purpose, but the eastern side of the structure had become significantly degraded. WRT, with funding from Defra's River Improvement Fund and with the services of engineer Pete Kerr of Northumberland Rivers Trust, developed a fish easement concept, remodelling the degraded section to allow fish access upstream during all flow conditions while continuing to provide Bedburn wildlife pond with water.
Removal of the weir was considered and rejected, as it was important to preserve the supply of water to the wildlife pond, and geomorphological advice from Prof. Malcolm Newson of the Tyne Rivers Trust suggested that removal would unlock very large quantities of impounded gravels, destabilising the sandy riverbanks adjacent to extensive public access and car-parking areas.
The weir is located close to a sandstone cliff face, where the burn turns at right angles; large boulders found at its base were perfect for incorporating into the weir to add strength and create a resting pool at the fish entry point to the easement. The collapsed section of the weir was dismantled and rebuilt with large boulders and existing stonework to create a stronger structure, incorporating a series of pools and a sluice to control water flowing across the fish pass and into the mill race. A tree trunk acting as a debris catcher has been tethered immediately upstream of the fish pass with the aim of diverting the large volumes of woody debris coming from the forest away from the pass and across the weir.
Hamsterley Forest is one of the biggest tourist attractions in County Durham. The access route for the construction site ran through the main visitor car park, so it was important that construction should be completed before the summer-holiday visitor peak, which left only a four-week window in which to complete the build.
The Forestry Commission, as landowners and joint owners of the weir together with a private landowner, were key partners in the delivery of the project. A Memorandum of Agreement has been agreed between WRT, the Forestry Commission and the private landowner regarding the maintenance of the structure.
Construction was achieved on time by contractors Owen Pugh despite an exceptionally wet June and July, when the burn rose over 2m, causing much lost time, the loss of 300 sandbags, and the need to redo three days’ work.
Electro-fishing upstream of the fish pass next summer will hopefully show increased numbers of migratory fish reaching the spawning grounds in the upper reaches of this burn.
Funders and supporters of the project: