The River Irt is situated in the Wasdale valley. The river is approximately 22km in length and flows out to sea at Ravenglass.
Mussels are still found within the river in very low numbers and are at risk of extinction if current trends are not reversed. Pressures include silt intrusion into gravel, agricultural runoff, lack of stable habitat due to past dredging or removal of boulders, invasive species and low host fish numbers in some areas.
The upper half of the river is dominated by granites, basalts and andesites. The lower half is formed of sandstones.
The River Irt is fished by a number of clubs and syndicates including: