Time series of daily measured river flows form the basis of National River Flow Archive information holdings. Gauged river flows at points on the river network across Great Britain and Northern Ireland are archived at a national level. An outline of how river flows are measured and hydrometry in the UK is given here.
NRFA data holdings are referenced to the location of river flow measurement, known as a gauging station. An outline of the UK gauging station network can be found here. River flow data held on the NRFA originate from gauging stations operated by a range of Measuring Authorities.
The NRFA collates records of the daily mean flow (otherwise known as, Gauged Daily Flows). A variety of additional river flow time series, derived data and calculated flow statistics are also available for some gauging stations.