The United Kingdom Acid Waters Monitoring Network (UKAWMN), funded by the Department of the Environment Food and Rural Affairs, and the Department of the Environment Northern Ireland, was established in 1988 to monitor the ecological impact of acid deposition in areas of the UK believed to be sensitive to acidification. 22 years on, its data-base provides a long-term record of water chemistry and biology which is unique for upland freshwater systems in the UK More information on this dataset can be found in the Freshwater Metadatabase - BF34 (http://www.freshwatermetadata.eu/metadb/bf_mdb_view.php?entryID=BF34).