Gathering high quality data on fragile freshwater ecosystems since 1988

UWMN conducts long-term monitoring of water quality and biodiversity in small upland lakes and streams threatened by air pollution, climate change and land use change. Our data informs policies and legislation with respect to air pollution effects and supports upland water management.


The UK Upland Waters Monitoring Network (UWMN) is designed to track changes in surface water quality and freshwater biodiversity across upland regions of the UK. It provides a unique long-term record (now over three decades in length) of the chemical, physical and biological status of upland lakes and streams in the UK.

The range of sites and measurements was initially focussed primarily on tracking the impact of acid rain, but have since been enhanced in order to address issues relating to the eutrophying influence of nitrogen deposition, effects of climate change and the impacts of changing land use and land management.

A brief history of UWMN

The UWMN developed from the earlier United Kingdom Acid Waters Monitoring Network (UK AWMN) that 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. AWMN was funded by a consortium originally led by the UK Department of the Environment, later to become the Department for Environment Food and Rural Affairs (Defra). Large cuts in funding since 2016 have resulted in some contraction of the network with residual support provided by a broader consortium of funders including the UK Centre for Ecology & Hydrology, Natural Resources Wales, Welsh Government, NatureScot and Forest Research, with considerable investments in kind from UCL, Queen Mary University of London, Marine Scotland and a number of dedicated volunteers.

UWMN is coordinated by the UK Centre for Ecology & Hydrology

Follow UMWN on Twitter: @UKUplandWaters

News & features

Key figures


Number of UWMN sites: 11 Lakes & 14 streams


Year the Acid Waters Monitoring Network (now UWMN) began


Years of operation


Peer reviewed scientific publications and book chapters

Photo credits on this page:

  • Banner, 'Sites' and 'Resources': Ewan Shilland
  • 'About': Ben Goldsmith
  • 'Methods': James Shilland