Yeovil Water Hardness & Quality Report (2026)

Yeovil, the south Somerset market town on the River Yeo, is supplied by Wessex Water from Sutton Bingham Reservoir immediately south-west of Yeovil, supplemented by the broader Wessex Water south Somerset network. Sutton Bingham Reservoir impounds the River Yeo in the Jurassic limestone and clay vale country of south Somerset — the valley here drains the Jurassic Inferior Oolite (Ham Hill Stone) limestone of the south Somerset Corallian ridge and the Blue Lias limestone-clay sequence of the Yeo valley floor. The Ham Hill oolite is a famous building stone of south Somerset, and its dissolution contributes significant dissolved calcium to the Yeo catchment and reservoir. Wessex Water treats Sutton Bingham supply and distributes to Yeovil and the south Somerset area, delivering consistently hard Jurassic limestone-derived water.

Yeovil's hard water — 239.5 mg/L (16.8°Clark) — reflects the Jurassic Inferior Oolite and Blue Lias limestone chemistry of the south Somerset Yeo catchment. The Ham Hill oolite and Lias limestone sequence of the south Somerset plateau and vale contribute very high dissolved calcium from carbonate dissolution, producing water hardness consistent with Taunton (240 mg/L) to the north-west on the same Wessex Water Somerset network. The Drinking Water Inspectorate (DWI) classifies this supply as hard.

Limescale is a persistent household challenge in Yeovil. At 239.5 mg/L, limescale forms in kettles within two to three weeks and monthly or fortnightly descaling is advisable. Combi-boiler heat exchangers accumulate deposits steadily — annual boiler servicing and fitting an in-line scale inhibitor are recommended. Showerheads, taps, and shower screens develop regular deposits. Washing-up liquid lathers poorly. Using Calgon monthly in the washing machine and maintaining a regular descaling routine is essential limescale management for Yeovil households on the Jurassic Somerset supply.