UK Water Quality Report • 2026 Data

Water Hardness in RH11

Water supply analysis across 5 postcode sectors in RH11 (Southern Water).

Outcode Avg Hardness280 PPMHard Water
Regional Quality Overview

Water Supply Analysis: Outcode RH11

Analyzing water quality disclosures across all 5 postcode sectors in outcode RH11 reveals an average water hardness of 280 PPM (Hard Water). Public water supply across this area is managed by Southern Water, responsible for treating and delivering water to residential households.

Water chemistry can fluctuate across supply zones in RH11. The lowest mineral concentration is recorded in sector RH11 0 at 280 PPM, whereas sector RH11 9 experiences higher mineral levels reaching 280 PPM.

Due to the hard water (280 PPM) in RH11, limescale build-up can occur on heating elements, shower heads, and boilers. Setting your dishwasher water softener to the correct level (e.g. Bosch setting H04) is strongly recommended to prevent cloudy glassware and internal scale accumulation. Review the individual postcode sectors below to get precise dishwasher salt settings and limescale recommendations.

Softest Sector in RH11

Lowest mineral concentration

Softest
Sector RH11 0233 Postcodes • Hard
280 PPM19.6 °Clark

Hardest Sector in RH11

Highest mineral concentration

Highest Hardness
Sector RH11 9293 Postcodes • Hard
280 PPM19.6 °Clark

All Postcode Sectors in RH11

Select a postcode sector below to view exact water softener salt settings, limescale protection guides, and appliance recommendations.