Shirley Water Hardness & Quality Report (2026)

Shirley, the residential suburb in the south of the Metropolitan Borough of Solihull, sits at the edge of the Birmingham conurbation and is served by Severn Trent Water. Like much of the West Midlands, supply depends upon a blend of soft upland water imported via the Elan Valley Aqueduct from central Wales, supplemented by abstraction from regional Permo-Triassic sandstone aquifers in the south Solihull and north Warwickshire belt. Water is treated at Frankley Water Treatment Works and at satellite treatment facilities before reaching Shirley's distribution mains. The notably high TDS of 614.2 mg/L relative to the hardness of 218 mg/L indicates a pronounced groundwater fraction carrying additional sulphate from the Triassic evaporite sequence beneath the area.

The Permo-Triassic sandstone aquifer beneath south Solihull and north Warwickshire carries water that has dissolved calcium and magnesium carbonates from secondary calcite cement within the sandstone, as well as sulphate from interbedded Triassic mudstone and gypsum horizons. The south Solihull supply zone lies further from the Elan Valley distribution axis, meaning a higher proportion of local groundwater reaches the distribution network here than in more central Birmingham zones. This accounts for both the elevated hardness and the high TDS compared with softer suburban areas closer to Frankley.

At 218 mg/L Shirley's water is hard, and limescale builds up steadily on any heated or exposed surface. Kettle elements typically require descaling every three to four weeks using a citric acid solution. Shower screens, tap nozzles and washing machine drums will all show progressive limescale accumulation. Washing-up liquid lathers less readily, so residents tend to use more than in soft-water households. Fitting a scale inhibitor upstream of combi-boilers and white goods is strongly recommended, and a whole-house water softener is worth considering given the elevated mineral load in Shirley's supply.