Acid Waters Monitoring Network


The United Kingdom Acid Waters Monitoring Network (UKAWMN), funded by a consortium led by the Department for Environment, Food and Rural Affairs, was established in 1988 to monitor the chemical and ecological impact of acid deposition in areas of the UK believed to be sensitive to acidification.  Over twenty years on, its database provides an extremely valuable long-term record of water chemistry and biology which is unique for upland freshwater systems in the UK.

What is measured?

Parameters Measured Monitoring sites and data
Streams are sampled monthly, and lakes quarterly, for a range of chemical and biological parameters Current sites: 22 (11 lakes, 11 Streams)
Total sites: 22
Data availability: 01/04/1996 to 01/04/2009. Older data is available (going back to 1988), but is not currently online.

What is the purpose of the network?

The Network has a wide geographical coverage, consisting of 11 lakes and 11 streams across the UK which are monitored chemically and biologically to monitor the ecological impact of acid deposition in areas of the UK believed to be sensitive to acidification. At all sites, regular spot samples are taken for laboratory analysis of an extensive range of chemical determinands, including pH, conductivity, dissolved organic carbon and a standard suite of base cations, anions and metals. At a subset of streams, pH, conductivity and stream flow are also continuously monitored to provide a more detailed record of acid episodes. Epilithic diatoms, aquatic macrophytes and benthic invertebrates are sampled annually in the spring/summer and fish surveys for stream sites and the outflow streams of lakes are conducted each autumn.

How is the network run?

The UKAWMN is coordinated by ENSIS, part of the Environmental Change Research Centre (ECRC) at University College London. Data are collected, analysed and collated by several laboratories throughout the UK. All data are stored in a database managed by the Centre for Ecology and Hydrology Wallingford and ENSIS. Summary data is available on request to scientific and other interested organisations.

View data for sites in this network

Data can be downloaded data from

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