Wessex Chalk Stream and Rivers Trust Teffont Hatches RIVer Easment (THRIVE)
Photo: Teffont Mill impoundment Summary: Teffont Mill is situated on the River Nadder (Middle- GB108043022470) which is part of the River Avon SAC and River Avon System SSSI. In addition, the mill is named in the River Avon Restoration Programme Project (RARP), forming the boundary between reaches N_15 and N_16. In the latest RARP strategy publication, the structure is reported as a significant barrier and in need of intervention. The structure is a partial barrier to Salmonids due to Atlantic Salmon (Salmo Salar) and Sea Trout (Salmo Trutta) having inconsistent passage. There is a perceived complete barrier to course fish due to the flume like weir sill which has a head loss of 100cm. As such, we aim to bypass the barrier using a rock ramp along the true right-hand bank through a section of mixed woodland. The easement channel will be 75m and has been designed to allow multi-species fish passage. This project aims to (1) improve fish passage around Teffont Mill to both course and game fish, (2) Enhance hydro-geomorphological processes by improving channel dynamics, namely longitudinal connectivity, (3) Improve current hatch management protocols, (4) Reduce flood risk to local property.
Project name: Teffont Mill Fish Easement Project Aim(s): Improve fish passage around Teffont Mill to both course and game fish. Enhance hydro-geomorphological processes by improving channel dynamics, namely longitudinal connectivity. Influence current hatch management protocols. Reduce flood risk to local property. Location: Teffont Mill, Wiltshire. Upper Grid reference: Lower Grid reference: Catchment: Hampshire Avon Waterbody: Nadder (Middle) Waterbody ID: GB108043022470 WFD status: Moderate – failing to achieve GES due to Phosphorous, Macrophytes and Phytobenthos. Protected areas: SSSI and SAC. RARP Reach: The weir is the border between N_15 and N_16.