The Langabhat catchment feeding the Grimersta covers an area of approximately 105 square kilometres. The underlying geology is predominantly slow weathering undifferentiated Lewisian Gneiss with typically nutrient poor (oligotrophic) lochs.
The catchment includes the Loch nan Eilean Valley Bog Site of Special Scientific Interest (SSSI). Much of the area is covered by the Lewis Peatlands Special Area of Conservation and Special Protection Area.
In 2005, the Langabhat catchment was designated as a Special Area of Conservation for Atlantic salmon under the EU Habitats Directive.
The original Langabhat Catchment Stock Assessment Report was produced in 2001 by the Outer Hebrides Fisheries Trust. This, and subsequent survey work, help inform fishery management planning and conservation policy. A link to publications of the Outer Hebrides Fisheries Trust is available here.
Langadale River (Abhainn Langadail) is the principal tributary (draining an area of 10 square kilometres) and one of the key spawning areas for the catchment. Over grazing here has led to a reduction in riparian vegetation leaving substantial lengths of bank subject to severe erosion and collapse. This has caused a widening of the river channel, an unstable river bed and down stream siltation.
The North Harris Trust undertook a planting scheme in Glen Langadale covering an area of 34 hectares of which 13 hectares will be afforested. Native broadleaves will cover 8.5 hectares with Caledonian Scots Pine (pinus sylvestris) covering 4 hectares.
A smaller scheme between the Linsiadar Grazings and Grimersta for the Eastern bank of the lower Grimersta River has been completed; further planting and habitat improvement continues to take place elsewhere on the system.
Please contact us if you would like further information on our conservation policies.