In the widest sense 'hydrometry' embraces the measurement of all of the elements in the hydrological cycle but the term is primarily applied to the measurement of river flows. Hydrometry has a long history but, in the UK, there were relatively few flow measurement (or ‘gauging’) stations prior to the 1960s. Thereafter, the network grew rapidly in response to a growing demand for river flow information and, today, there are more than 1500 gauging stations in the national network. The Centre for Ecology & Hydrology manages the National River Flow Archive, in collaboration with the Measuring Authorities, and endeavours to maximise both the quality and utility of the hydrometric data under its stewardship.
These pages provide a background to the measurement, management and use of river flow data in the UK.