Crawley Water Hardness & Quality Report (2026)

South East Water is the water and sewerage undertaker for Crawley and surrounding areas in West Sussex, East Sussex, and Kent. The utility draws water from multiple sources, primarily the Chalk aquifer, a significant groundwater source within the High Weald and South Downs regions. Surface water from reservoirs like Bewl Water and Ardingly Reservoir also contributes to the supply. Water undergoes treatment at various plants across the service area before reaching the approximately 2.3 million people served.

The water's hardness stems from the Upper Cretaceous Chalk aquifer, which is naturally rich in dissolved calcium and magnesium. This chalk bedrock lies beneath Weald geology featuring Cretaceous sandstones and clays. As water percolates through these layers, it accumulates significant mineral content, characteristic of the region's supply. Surface water from reservoirs in the Weald further influences the overall mineral load.

Residents in Crawley will likely notice scale buildup in appliances like kettles and boilers due to the hard water. This can reduce the efficiency and lifespan of dishwashers and washing machines, making regular descaling of hot water systems and cleaning of aerators a good idea. Many households find that installing point-of-use or whole-house water softeners significantly reduces limescale. South East Water treats all its water to meet stringent UK Drinking Water Standards, ensuring microbiological safety through processes like coagulation, filtration, and chlorination.