Kidderminster Water Hardness & Quality Report (2026)

Kidderminster, the north Worcestershire carpet-making town on the River Stour, is supplied by Severn Trent Water from the Elan Valley Reservoir system in mid-Wales and the River Stour catchment supply. The Elan Valley upland reservoir supply provides the primary soft-water input to the West Midlands network, distributed via the West Midlands Aqueduct and Frankley Water Treatment Works. However, Kidderminster's position on the River Stour — which rises on the Clent Hills and flows through the north Worcestershire and south Black Country industrial corridor — means the local Stour catchment and Triassic Sherwood Sandstone and Coal Measures groundwater of the Stour valley contribute moderately hard water to the distribution blend. This raises the supply well above the soft Elan Valley baseline.

Kidderminster's hardness of 180 mg/L (12.6°Clark) reflects the Stour catchment and Triassic Sandstone groundwater influence in the north Worcestershire supply zone. The Triassic Sherwood Sandstone aquifer beneath the north Worcestershire plain and the River Stour drainage over Coal Measures and Triassic country contribute dissolved calcium to the network blend. The Drinking Water Inspectorate (DWI) classifies this supply as moderately hard.

Limescale is a regular household concern in Kidderminster. At 180 mg/L, limescale forms in kettles within three to four weeks and monthly descaling is sensible. Combi-boiler heat exchangers accumulate deposits at a moderate rate; annual servicing with a limescale check and a scale inhibitor are recommended. Showerheads and taps develop consistent deposits. Washing-up liquid lathers moderately. Using Calgon monthly in the washing machine and a regular descaling routine is appropriate limescale management for Kidderminster households.