River Ayr

Ayrshire’s largest river rises at Glenbuck reservoir on the boundary of Ayrshire and Lanarkshire and flows westwards 65 km to its estuary at Ayr on the Firth of Clyde.

The River Ayr has a catchment area of 574kmand its principal tributaries include the Greenock Water, Lugar Water, Water of Fail and Water of Coyle.

Principal land uses in the catchment area are agriculture, forestry, mineral extraction, leisure and recreation and urban development, the largest settlements being Ayr, Cumnock, Catrine, Ochiltree, Muirkirk and Sorn.

Notable features include Sites of Special Scientific Interest (SSSI’s) at Howford, near Mauchline and the Failford Gorge, Catrine Dam and hydro scheme and the newly completed Nethermills Archimedes Screw Hydro at Ayr.

Fish species include salmon, sea trout, brown trout, grayling, eel, stickleback, minnow and stone loach.

River management is undertaken by the River Ayr District Salmon Fishery Board, riparian owners and numerous angling clubs along the river. Ayrshire Rivers Trust works closely with river managers and provides advice and guidance on all aspects within the catchment.


River Ayr Fishery Management Plan

(information, data and content held within this FMP cannot be used or shared without prior written permission):

River Ayr Catchment Map highlighting all tributaries.

Support us!

Every small donation helps! Payment by credit/debit card is quick and easy.

To view current River Ayr water levels:

Key Features


  • Largest river in Ayrshire
  • Large human population in middle and upper reaches, e.g. Cumnock
  • Intensive dairy farming thoughout the catchment
  • ‘Source to sea’ River Ayr Way opened by East Ayrshire Council in 2006
  • High scenic value in areas such as Failford Gorge SSSI and in and around Mauchline and Catrine

Catchment Characteristics

  • Productive soils on Permian sandstones and the Carboniferous Scottish Coal Measures including cyclic sedimentary deposits of economic value
  • Salmon in tributaries with altitudes over 300m, highest reached by salmon in Ayrshire
  • No large natural stillwaters in catchment, although many small lochs stocked with rainbow trout

Industrial Past

  • Very high conductivity levels, increasing with distance from sea, primarily due to inputs from historic and mining activities
  • Iron input from resurging minewater in upper catchment 
  • Industrial heritage of mining and mills e.g. Catrine Dam which is registered as a recognised Ancient Monument
  • Several old mill structures hinder fish migration
  • Modern industry e.g. chipboard plant, opencast mines
  • Constant threat of pollution from operational and disused coal mines
  • Low impact of conifer forestry and acidification compared to other Ayrshire rivers


  • Juvenile salmonid production greatest in cleaner upper tributaties
  • Grayling population unique in Ayrshire from source to sea except on the Luggar upstream of Ochiltree weir. (River Irvine population extinct)
  • All three native lamprey species have been recorded
  • Otters are present throughout catchment 
  • Water voles are present in some upper reaches

 Monitoring and science on the River Ayr

Data is collected to allow evidence based management and restoration



We undertake annual electrofishing surveys on behalf of the River Ayr District Salmon Fishery Board to monitor fish production in the main stem and tributaries.

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

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.

Giant hogweed control on the River Ayr is one of the longest established control programmes in Scotland.


ART have produced a habitat assessment and fishery management plan for the River Ayr DSFB to guide the Board in management priorities. There are many challenges to overcome within the catchment that will require considerable investment and funding.


There is an ever increasing interest in lamprey species across the UK. Lamprey are an important species within the Ayr catchment and ART hold considerable data on their distribution. The Ayr supports all three native lamprey species and appear to be stable. River Lamprey are protected as a schedule 3 fish species of the Conservation (Natural Habitats, &C) Regulations 1994. River and sea lamprey are a UK BAP species. Brook lamprey are listed on the International Union for Conservation of Nature (IUCN) Red List of threatened species.

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.

Water Temperature Monitoring

ART are a partner within the Scotland River Temperature Monitoring Network (SRTMN) to identify temporal changes in river temperature and the effects of management actions such as tree planting. Data collected from the river Ayr can be used to model improvements on other local rivers.

Atlantic Salmon Pressures Tool


ART contributed to the development of Fishery Management Scotland’s Atlantic Slamon 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 tagert management actions and to provide importnat evidence for policy development at national level. This tool will align very well with the forthcoming Fisher Management Plans that the Trust are currently developing for FMS.