Salisbury Water Hardness & Quality Report (2026)

Wessex Water draws its supply for Salisbury from a mix of sources, primarily the River Avon and groundwater from the Wiltshire Chalk Aquifer. The water originates from chalk springs and boreholes tapping into the Cretaceous Chalk formations beneath the Wiltshire and Hampshire Downs. This chalk bedrock is the defining characteristic of the region's water supply, contributing to its distinct quality before it reaches residents' taps.

The geology here is dominated by the Cretaceous Chalk, a layer of porous limestone formed millions of years ago. This chalk bedrock acts as a natural filter but also readily dissolves minerals like calcium and magnesium as water percolates through it. Consequently, the water flowing from the River Avon catchment and the Wiltshire Chalk Aquifer is naturally very hard, registering around 19.0° Clark degrees.

This very hard water can lead to scale buildup in appliances like kettles, washing machines, and particularly water heaters, potentially shortening their lifespan. You might also notice reduced lathering from soaps and detergents. To combat scale, regular descaling of appliances is recommended. For those concerned about the impact on plumbing and appliances, installing a water softener is a common solution in areas with chalk-derived water supplies.