River Eachaig habitat improvement project (2021-2026)
AFT have been working to improve fish habitat in the River Eachaig since 2021 by improving the quality and quantity of bankside and instream cover for fish through a range of techniques.
The sandy loose soils in the Cowal region of Argyll make the very susceptible to erosion and collapse when the bankside armouring of trees are lost. Bank erosion on the River Eachaig, an important salmon and sea trout fishery, has left the river ever wider and the water ever shallower in important fish refuge pools. Delivery of new substrates into the river channel are driven by climate change driven intensive rainfall events which are exacerbated by land drainage in the tributaries.
Collapsed riverbanks and fallen trees are a new feature of the River Eachaig as large amounts of riverbed sediments deposit in the channel
Although deposition of new gravel is a natural process, the resulting loss of bankside trees leaves the water exposed to over-warming due to lack of shade and reduce bankside cover for fish. While retaining useful fallen timber in the river, AFT have worked with landowners and the Eachaig Fishing Syndicate with financial support from the Loch Lomond & Trossachs National Park Authority to kick-start the process of reducing severe erosion by revegetating the riverbanks. A mix of green bank revetment and coarse wood placement has been used as a first step in the process where recycled Christmas trees and forestry brash have been pinned to the foot of the riverbank using untreated larch posts driven into the bed of the river.
Green bank revetment installation on an collapsed bank
The bank is regraded using a track machine and willow pegs and whips planted to begin the process of bank revegetation. This work begins the process of bank stabilisation and buys time for existing and newly planted trees to colonise more of the bank. New fencing has also been installed along 500 m of riverbank in 2025 and 1,500 new trees planted with guards.
New fencing and tree planting in an expanded riparian zone
The River Eachaig has a significant problem with invasive plants colonising the banks which are being treated with the help of contractors. Following a survey by AFT, this work will be expanded further across the catchment of Loch Eck and the River Curr in future years.
Dense patch of Himalayan Balsam being treated
More work to replace damaged fencing, planting new trees, eradicating invasive plants, and repairing new sections of bank and maintaining the existing green bank revetments are being planned for 2026.