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


  • 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


  • 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


Comprehensive electrofishing surveys on behalf of the River Irvine Angling Improvement Association completed in 2003 and 2005 to investigate fish populations throughout the catchment.

We have a large database which may be available upon request for those requiring information.


Phase One Salmonid Habitat survey of the Irvine main stem and some of the tributaries published in 2003. The survey found that good juvenile salmonid habitat was limited in the lower main stem due to low gradient and human influences such as canalisation. Habitat degradation was also an issue in some parts of the upper reaches, primarily from livestock farming. The significance of the many weirs in the catchment was also highlighted.

Invertebrate Sampling


Invertebrates respond to long term changes in water quality therefore they can be used to determine pollution problems. ART provide various levels of assessment both commercially and for our own use.

Invertebrate sampling offers opportunities for citizen science.

Invasive Species Management


Over many years, ART have undertaken scientific habitat assessment to determine distribution and impacts with invasive species. Invasive weeds can have an impact on habitat and water quality. Through strategic management and control we continue to address issues created by these species. 


Fish Rescues


Fish rescues and follow up monitoring conducted in 2012 & 2013 due to the need for essential maintenance on the storm water overflow system running along the banks of the Kilmarnock Water


Atlantic Salmon Pressures Tool


ART contributed to the development of Fishery Management Scotland’s Atlantic Salmon Pressures Tool. This involved looking at all pressures affecting the species across Ayrshire. The FMS Pressures tool is an interactive mapping platform that will be  available to local river managers to inform and target management actions and to provide important evidence for policy development at national level. This tool will align very well with the forthcoming Fishery Management Plans that the Trust are currently developing for FMS.