Allt Lorgy site visit, Scottish Highlands

Guest blog - Ann Skinner, RRC Board

8 members attended a fantastic site visit to the Allt Lorgy in Cairngorm on Wednesday 13th April 2022, the first since the beginning of the pandemic! This project won the UK River Prize in 2020 for reach scale, process-based river restoration resulting in a self-sustaining system, and now provides an important demonstration site for landowners, Fisheries Boards and students.

The river had been canalised, straightened and regularly dredged in an unsuccessful attempt to intensify floodplain land use, creating 2m high embankments and a uniform, armoured bed. Large blocks of stone had been used in an attempt to reduce the subsequent erosion and incision - these were replaced with large woody material. The Seafield Estate gave the designers a blank canvas, providing the work improved the fishery of the Spey. Prior to the works, no sea trout or salmon were observed in this stretch; both species now breed here.

The main aim was to remove constraints and kick start natural sediment transfer processes and dynamic morphology. As one of the first projects in Scotland using large wood to restore natural processes, every structure was initially deemed to need a (CAR) licence. SEPA subsequently acknowledged large wood as an environmental service, thus obviating the need. None of the large woody material was anchored, and only one structure has moved despite many spates because the whole tree root ball is used, sunk into the bed or banks of the river.