The collection consists of reports, surveys, data records, maps, administrative records and other material relating to the work of the Environment Agency (and of its predecessor organisations the various River Boards, River Authorities, Water Authorities and the National Rivers Authority). While a few documents date back to the 19th century and earlier, the majority spans the 1930s to the 1990s.
Most of the collection relates to the Agency's monitoring and management of the area's river and lake catchments, with an emphasis on fisheries, biodiversity, constructions such as fish passes, weirs and fish traps, fish diseases, water quality and pollution. Included are papers relating to the Agency's corporate, strategy and public affairs, as well as information on regional and national byelaws, net limitation orders and historic fishery rights.
The majority of the collection covers the EA North West region, but there is also a range of material on the EA South West region. The geographic scope for the North West is broadly Cumbria and Lancashire and the wider catchment areas of (from north to south) the Rivers Eden, Derwent, Kent, Leven, Lune, Wyre, Ribble, Mersey and various smaller rivers. The largest body of material for the EA North West region relates to catchment studies of the Mersey area in relation to planning for Manchester Airport's second runway. A number of reports also relate to the monitoring of the Cheshire Meres, and information on the past flooding of the Kent and Leven catchment.
For the EA South West, catchment areas include North Devon, South Devon, Tamar and North Cornwall, which includes the River Seaton, Looe and Fowey and their tributaries. There is a large body of information including maps on redd counts for various rivers for the 1980s and 1990s, information relating to fisheries and management of Roadford Reservoir, and fishery data collected from Colliford Lake and Restormel Weir.