Willenhall Water Hardness & Quality Report (2026)

Willenhall, in the Metropolitan Borough of Walsall in the north Black Country, is supplied by Severn Trent Water from the Elan Valley Reservoir system in mid-Wales via the West Midlands Aqueduct to Frankley Water Treatment Works. The Elan Valley supply, drawing from the very soft Cambrian Mountain upland reservoir catchments of mid-Wales, dominates the north Black Country supply blend. Willenhall's position in north Walsall is less influenced by the Triassic sandstone groundwater contributions that moderate the hardness in south Dudley and Sandwell supply zones — the north Walsall distribution zone receives a proportionally higher Elan Valley input, keeping the supply in the moderately soft range. The Black Country coal measures and Triassic sandstone beneath Willenhall contribute a small calcium increment through the distribution network.

Willenhall's hardness of 98.5 mg/L (6.9°Clark) — considerably lower than Smethwick (165 mg/L) — reflects the higher Elan Valley soft-water proportion in the north Walsall distribution zone. Willenhall is among the softer Black Country supply zones, benefiting from the dominance of the Welsh upland aqueduct supply. The Drinking Water Inspectorate (DWI) classifies this supply as moderately soft.

Limescale is minor in Willenhall. At 98.5 mg/L, limescale builds slowly and kettles need descaling every two to three months. Combi-boiler heat exchangers accumulate minimal to moderate deposits; annual servicing is good practice. Showerheads and taps remain largely clear. Washing-up liquid lathers reasonably well. Using Calgon monthly in the washing machine and a regular kettle descale is adequate limescale management for most Willenhall households on the Elan Valley supply.