Leicester Water Hardness & Quality Report (2026)

Leicester's water supply is managed by Severn Trent Water, drawing from several sources in the East Midlands. Rutland Water — the largest man-made reservoir in England by surface area, completed in 1975 — is a primary source, fed by transferred water from the River Welland and River Nene catchments. Additional supply comes from the River Soar and River Wreake abstractions and from licensed groundwater boreholes in the Triassic Sherwood Sandstone aquifer beneath Leicestershire. Water is treated at Staunton Harold Water Treatment Works and other Severn Trent facilities before distribution to the city of Leicester and the surrounding county.

Leicester's hardness of 170 mg/L (11.9°Clark) reflects the mixed surface and groundwater geology of the East Midlands. Rutland Water's feeder rivers — the Welland and Nene — drain across extensive Jurassic limestone and lias clay outcrops in Northamptonshire and Rutland, where carbonate dissolution adds significant calcium. The groundwater component from Sherwood Sandstone boreholes adds further mineral content from Triassic deposits. The blend places Leicester's water firmly in the moderately hard classification of the Drinking Water Inspectorate (DWI) — harder than the Midlands' western cities supplied by the Elan Valley, but softer than the chalk-belt South East.

Limescale is a regular maintenance task for Leicester households. At 170 mg/L, kettles develop a noticeable white limescale crust within four to six weeks of daily use, and monthly descaling with a commercial descaler or diluted citric acid is advisable. Combi-boiler efficiency is meaningfully affected by limescale over several years — annual boiler servicing should include checks for heat exchanger deposits, and fitting a scale inhibitor cartridge to the boiler feed is a practical investment. Limescale also builds up on taps and showerheads at a steady rate. Washing-up liquid lathers adequately but noticeably less well than in softer-water cities. Using Calgon or a limescale inhibitor tablet in the washing machine each cycle is a sensible precaution.