[1][2] The Salwarpe is formed by the confluence of the Battlefield and Spadesbourne Brooks in Bromsgrove; it then passes Stoke Prior, Upton Warren, Wychbold, and Droitwich.

The long-term record shows that the catchment of 184 square kilometres (71 sq mi) to the gauging station yielded an average flow of 1.35 cubic metres per second (48 cu ft/s).

[6] The Salwarpe catchment upstream of the station has an average annual rainfall of 666 millimetres (26.2 in) and a maximum altitude of 294 metres (965 ft) at Beacon Hill, in Lickey Hills Country Park at its north-eastern edge.

Several components are used to determine this, including biological status, which looks at the quantity and varieties of invertebrates, angiosperms and fish.

The water quality of all the riverine waterbodies in the lower catchment have regressed from moderate in 2009 to poor in 2016.