Chichester Water Hardness & Quality Report (2026)

Chichester receives its water supply from South East Water, which draws primarily from groundwater sources. These sources are located within the South Downs, tapping into the Southern Chalk Aquifer through various boreholes. The water undergoes essential treatment processes, including filtration and disinfection, at local facilities before being distributed to residents in Chichester and surrounding areas like PO19. The South Downs watershed plays a crucial role, as precipitation here infiltrates the chalky soils and bedrock of the Upper Cretaceous Southern Chalk Aquifer. This extensive limestone aquifer, known for its fractured chalk rock formations, allows rainwater to percolate deep within the ground.

This groundwater originates from the porous chalk soils prevalent in the South Downs region of southern England. These chalk formations, part of the Upper Cretaceous period and specifically the Southern Chalk Aquifer, are composed of calcareous bedrock. As rainwater filters through this limestone matrix, it dissolves significant amounts of calcium carbonate, leading to a naturally hard water profile. The geological makeup of these chalk layers is responsible for the elevated levels of calcium and magnesium ions found in the water, creating a mineral-rich supply without the influence of surface water.

Homeowners in areas with very hard water often notice significant limescale buildup in appliances such as kettles, boilers, and showerheads, which can reduce their efficiency and lifespan. Washing machines and dishwashers are particularly susceptible, developing white deposits and potentially suffering damage to heating elements. To combat this, regular descaling with common household ingredients like vinegar or citric acid is advised, alongside monthly cleaning of taps and filters. For those experiencing these issues, installing a water softener is highly recommended to prevent limescale damage, improve the lathering of soaps, and protect skin and hair from dryness.