River Irvine
Ayrshire’s second largest river rises above Loudoun Hill on the boundary of East Ayrshire and Lanarkshire.
The Irvine flows for 42km westwards to Irvine Bay on the Firth of Clyde.
It shares an extensive estuary with the River Garnock. This is the only significant estuary in Ayrshire, providing excellent bird habitat.
Principal land uses in the catchment area are agriculture, forestry, and urban development, the largest settlements being Irvine, Kilmarnock, Irvine, Stewarton, Galston, Newmilns and Darvel. The river has been highly modified, particularly where it flows through urban areas, with many weirs, culverts and retaining walls. There is a large flood prevention scheme in development between Hurlford and Galston.
Fishery management is undertaken by the River Irvine Angling Improvement Association and the many active angling clubs.

River Irvine Catchment Map highlighting main tributaries.
Support us!
Every small donation helps! Payment by credit/debit card is quick and easy.
Key Features
General
- Medium-sized river with catchment of >380km2. Second largest catchment of Ayrshire rivers
- Rises above Loudoun Hill where it is known as the “Wee Irvine”
- Headwater’s of the Craufurdland Water have been impounded for water supply reservoirs. There is a compensation flow of 1.7Ml/day
- High human population density equivalent to 295 people/km2 within the catchment
- There have been a number of fish kills on the Irvine in recent years with the most recent occurring in November 2006, upstream of Priestland
Catchment Characteristics
- Major tributaries are the Glen Water, Glenoul Water, Cessnock, Fenwick and Craufurdland Water, Kilmarnock Water, Carmel Water and Annick Water
- River is extensively urbanised where it flows through settlements of Darvel, Newmilns, Galston, Hurlford, Kilmarnock and Irvine
- Annick Water is the largest tributary with a catchment area of 91km2
Industrial Past
- No major sewage treatment works as all sewage is pumped to the coast for treatment
- Water quality in many reaches of the main river and tributaries suffer from the impacts of diffuse pollution, primarily from agricultural land use. 62% of catchment land use is improved grassland
- Irvine is recovering from it’s past history as an industrial river, although a legacy of many weirs remain, some of which are serious obstacles to migratory fish
Biodiversity
- Salmon and sea trout are prevented from accessing the Fenwick and Craufurdland waters due to instream modifications at the Black Rocks Waterfall in Kilmarnock
- Common fish species present include salmon, trout, eels, stone loach, minnows, sticklebacks, lampreys. There is a population of Gudgeon in the lower river, which is unique within Ayrshire
- Grayling population, which were introduced in the 1850s is thought to have died out
- The Irvine’s population of freshwater pearl mussels is thought to have died out
River Irvine Gallery
Monitoring and Science on the River Irvine
Data is collected to allow evidence based management and restoration