UK Water Quality Report • 2026 Data

Water Hardness in NW11

Water supply analysis across 6 postcode sectors in NW11 (Thames Water).

Outcode Avg Hardness277.5 PPMHard Water
Regional Quality Overview

Water Supply Analysis: Outcode NW11

Looking for water hardness metrics in NW11? Water supplied by Thames Water in this outcode registers a baseline average of 277.5 PPM across 6 distinct postcode sectors.

Water chemistry can fluctuate across supply zones in NW11. The lowest mineral concentration is recorded in sector NW11 0 at 275 PPM, whereas sector NW11 6 experiences higher mineral levels reaching 290 PPM.

Due to the hard water (277.5 PPM) in NW11, 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 NW11

Lowest mineral concentration

Softest
Sector NW11 0128 Postcodes • Hard
275 PPM19.3 °Clark

Hardest Sector in NW11

Highest mineral concentration

Highest Hardness
Sector NW11 6199 Postcodes • Hard
290 PPM20.3 °Clark

All Postcode Sectors in NW11

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