Shrewsbury Water Hardness & Quality Report (2026)

Shrewsbury, the county town of Shropshire in a meander loop of the River Severn, is supplied by Severn Trent Water from the River Severn and the Elan Valley Reservoir aqueduct supply from mid-Wales. The Severn at Shrewsbury is fed by a varied upland Welsh and Shropshire catchment — draining upland Cambrian mudstones and shales in mid-Wales, the Shropshire Hills AONB (including Precambrian, Cambrian, and Ordovician terrain), and Carboniferous limestone country of the south Shropshire border. Severn Trent Water treats the Severn abstraction at Shelton Water Treatment Works in Shrewsbury, blending with Welsh Elan Valley supply to maintain a consistent treated output for the town. The blend of soft upland Welsh supply and more mineralised Shropshire Severn catchment water produces a moderately hard result.

Shrewsbury's hardness of 150 mg/L (10.5°Clark) reflects the blend of soft Elan Valley upland water and more mineralised River Severn catchment contributions. The Severn above Shrewsbury collects some calcium from Carboniferous Limestone and Devonian Old Red Sandstone in its Shropshire and Welsh Borders tributaries. Local Triassic Sherwood Sandstone groundwater in the Shropshire plain adds a further moderate calcium increment to the distribution blend. The Drinking Water Inspectorate (DWI) classifies this supply as moderately hard.

Limescale is a moderate household concern in Shrewsbury. At 150 mg/L, limescale forms gradually in kettles and descaling every one to two months is typically sufficient. Combi-boiler heat exchangers accumulate modest deposits and annual servicing with a limescale check is sensible. Showerheads and taps develop light to moderate deposits. Washing-up liquid lathers reasonably well. Using Calgon monthly in the washing machine and a kettle descale every couple of months is adequate limescale management for most Shrewsbury households.