Catcleugh Reservoir has been designated as a Local Wildlife Site, and is surrounded by a mixture of native and conifer woodlands.

The surrounding moorland is a Site of Special Scientific Interest because of the mosaic of heather and upland grassland.

Osprey are known to have used this site for roosting; buzzards are regular visitors, and there are occasional records of golden eagle.

[3] A variety of mammals occur here including otter, red squirrel, badger, roe deer, and bat.

Red squirrels live in the conifer plantations around the reservoir where mature trees provide a good supply of seeds.