The River Surveillance Network (RSN) is a statistically designed national monitoring network consisting of an unbiased and representative set of monitoring sites across English rivers. It will give a clear picture of river health across England by monitoring a wide range of parameters, supporting long-term measurement and detection of change. RSN monitoring follows a five-year panel design that balances temporal and spatial coverage. Across the five-year cycle, 1,600 unique sites will be monitored.
This Analysis Ready Dataset contains details of the network design and sampling locations, alongside water quality samples, ecology samples and habitat surveys carried out at RSN sites since 01 January 2021. When fully implemented, the RSN will provide a nationally representative dataset to support robust national insights. This release of the data reflects a network that is still in development, so users should be aware of current limitations related to representativeness, sampling balance, data variability, and exclusions.
The River Surveillance Network is a project funded by the UK Government through Defra's Natural Capital and Ecosystem Assessment (NCEA) programme. The NCEA is Defra's largest research and development (R&D) programme. It will produce a baseline of our natural assets by 2029; enabling a natural capital approach to policy and decision-making.
Users should ensure they have read the NCEA Analysis Ready Data Limitations Statement and dataset specific limitations/caveats outlined in the Data Dictionary. Attribution statement: © Environment Agency copyright and/or database right 2025. All rights reserved.
