Saltash Water Hardness & Quality Report (2026)

South West Water supplies Saltash, the historic toll-bridge town on the Cornish bank of the River Tamar directly opposite Plymouth, from Burrator Reservoir on the Dartmoor granite fringe blended with Tamar Valley sources and the east Cornwall supply infrastructure, treated at Burrator Water Treatment Works before distribution via the Plymouth–Tamar water network. At 234.5 mg/L (16.4°Clark), Saltash's water is hard — strikingly harder than the typically very soft water of west Cornwall — reflecting the dominant influence of the Plymouth and east Cornwall supply system, which draws substantially from water that has passed through Devonian and Carboniferous limestone formations in the Tamar and Tavy catchments.

While Burrator Reservoir sits on the Dartmoor granite — one of the softest source waters in Britain — the Plymouth–Tamar supply zone blends this granite reservoir water with contributions from surface water and groundwater in the Devonian limestone and Carboniferous limestone geology of the Tamar Valley and south-east Cornwall. The Cattewater and Plymouth Limestone formations, the Devonian reef limestone at Plymstock, and the Tamar Valley carbonate formations all contribute dissolved calcium to the distribution blend reaching Saltash. The resulting 234.5 mg/L is far harder than west Cornish granite-supplied communities.

At 234.5 mg/L, limescale is a persistent household challenge in Saltash. Kettles should be descaled monthly to maintain efficiency. The combi-boiler benefits from a fitted scale inhibitor and annual professional servicing. Washing-up liquid requires more product than in softer areas to achieve satisfactory lather. Taps and shower heads develop visible white limescale within one to two weeks; a fortnightly wipe with white vinegar or a proprietary descaling solution keeps fittings clean in this unusually hard east Cornwall Tamar Valley supply zone.