UK water hardness map by supply zone

Every area we hold a figure for

Why this is a list and not a drawn map

The supply-area boundary layer this site resolves postcodes against is read for its attributes only — company, acronym, type and area served — and not for its geometry. Nothing here holds the polygons, so nothing here can draw them.

Rather than publish a picture nobody measured, this page publishes what a map would tell you, as text: every supply zone we hold a figure for, the company that supplies it, the figure, the regulator's band for that figure, and the report it came from. It works in a browser with scripts switched off, and a screen reader can read it, which a drawn map would not be without this table underneath it anyway.

What this list covers, and what it leaves out

Every row here is a zone whose own water company published a hardness figure for it. A zone missing from this list is a zone whose company publishes nothing this site can read in bulk — not a zone with soft water, and not a zone that does not exist.

The hub page sets out which companies those are, what was read for each and when.

More on this

• Hard water in the UK
• Check your postcode