WGWaterGrade
Menu

Water hardness in Scotland

Find the supply-zone name serving your postcode, then explore the published hardness and its history. A supply zone is an area Scottish Water uses for its water reports; it is not necessarily the same as a town. WaterGrade does not guess your zone from a nearby town.

1. Find your zone using the official postcode checker

Enter your full postcode on Scottish Water’s website and note the “Site Name” in the result. Return here and search for that exact name. If no result appears, or the name is unclear, ask Scottish Water to confirm your supply.

Open Scottish Water’s postcode checker ↗

Our own automated postcode lookup does not yet cover Scotland. This route uses the supplier’s checker directly.

2. Read the hardness figure and its reporting year

The latest annual hardness edition we hold is 2024, covering 277 named supply areas. Scottish Water calculates the figures from annual calcium and magnesium measurements. These are source-area results, not tests at every home.

Across those reported areas, published hardness ranges from 4.84 to 341.49 mg/l as calcium carbonate. This range does not describe population coverage or a safety ranking.

Hardness is a measure of dissolved minerals. Match the units to your appliance manual before choosing settings; it is not an overall water-quality score. Suppliers may use different descriptive hardness bands, so compare the number and units as well as the label.

Convert hardness into the units in your manual

Find a named source area

Use the exact zone or ward name from your supplier’s checker. These are published source areas, not postcode matches. Older areas may have been renamed or replaced; the latest reporting period we hold is shown for each.

277 source areas match; showing the first 50.

Find your supplier’s official checker

3. Compare verified annual reports

Open a source-area report to see earlier editions where available. We hold Scottish hardness tables from 2016 onwards and keep differently named areas separate. A history for a zone does not prove that the same boundary or supply served your address throughout.

For an example of the format, Glencorse C has a verified annual series. It is an example source area, not a substitute for checking your postcode.

Sources and limits

A newer water-quality report may cover a different period from the hardness table. We keep those dates separate. The hardness table does not contain all chemical or microbial results, and Scottish Water’s mains reports do not establish the quality of a private well or borehole.

Catalogue and source files checked 6 September 2026. Browser collection is required for this source; the displayed year is the reporting year, not the download date.