Is Scottish water hard or soft?

Part of our hard water guide

Moving to Glasgow or Aberdeen and wondering whether the kettle will fur up? Scotland's own figures answer that for each zone, and a 20-in-1 strip can check your own tap.

By Andrew Tomlinson, WaterKit · Last reviewed 29 October 2026

How many of Scotland's supply zones are soft?

Most of them, 214 of 277 by our count. Scottish Water's hardness table gives each regulatory supply zone's 2024 average hardness in milligrams per litre (mg/l) of calcium carbonate. Its hardness factsheet sets six bands and says there are no regulatory limits for hardness. We sorted the zones into those bands ourselves from the hardness figures.

That is 23 zones at 100 mg/l or more. These are counts of zones, not of homes or people. Scottish Water's publications page lists this file as its newest hardness table, though it describes the contents as 2023 results while the PDF says 2024.

Which parts of Scotland have harder water?

A mix of island and mainland zones. Several Orkney zones, Fair Isle and Lismore are among the harder ones, alongside mainland zones such as Cargen and Newcastleton. Here are zones picked from the 2024 table, with Scottish Water's figures and our banding. They are examples, not a map.

North Ronaldsay is the highest figure we found. Many zones are named after areas rather than towns, so use Scottish Water's water quality search to find yours. Our Scottish tap water guide covers the wider quality picture.

Why is Scotland's water mostly soft?

Scottish Water's pages point to the source. It says all its water comes from rain, surface water supplies most customers and a few get groundwater. Its factsheet says most raw water comes from lochs, rivers and burns and tends to be soft to slightly hard, while water from boreholes in rock or gravel aquifers tends to be harder. We have not matched individual zones to their sources.

Why might your tap differ from the area figure?

Because the table is a 2024 average for a whole zone, calculated from Scottish Water's calcium and magnesium results, not a reading at your tap. The area figure is an average. Your tap may sit above or below it, and zones with similar names can differ a lot. In the same table Lomond Hills is 55.55 mg/l and Lomond Hills Borehole Mix is 141.90. A figure for the area does not tell you what comes out of your own tap.

“The area figure is an average for the whole zone, so I would never treat it as a reading from your own kitchen tap. If you want to know where your tap actually sits, a quick check with a strip is a sensible way to see how it compares.”

Hardness matters in the kitchen mostly through scale. Scottish Water's factsheet says temporary hardness is responsible for limescale in hot water pipes and kettles and can be removed by boiling, and lists scale on heating elements, reduced flow in hot water pipes and reduced lathering of soaps among the effects. Where water is soft those effects should be smaller, which is our inference from the figures. Our limescale guide and kettle guide go further, and a hardness strip shows where your own tap sits.

What one reader found

A poster on a coffee forum described moving back to Scotland after almost 20 years in the London area. They wrote "The water is soft and the pH is right around 7", said they noticed little chlorine smell or taste, and described the water in the south as very hard. They had used a filter in London and asked whether anyone in a soft water area bothers with one. It is one person's description, which we have not checked. Shared on Coffee Forums UK.

How can I check my own tap?

Look up your zone, then test your own tap. Scottish Water's postcode search names the zone, and the table lists its figure by name. The factsheet says Scottish Water can give hardness information for any supply zone through its Customer Helpline. Our hardness by postcode guide covers England and Wales.

The strip has a hardness pad. Fill a clean glass or cup with tap water, dip one strip, wait 30 to 60 seconds and match the pad to the chart, or enter the colours in the free results checker. Our hardness testing guide has the full method.

The pad has colour steps at 0, 25, 50, 100, 250 and 425 mg/l. The rest is our own reading of the chart, not Scottish Water's. The pad's unit basis is unconfirmed, so we read it as calcium carbonate. On that reading, zones at 16 to 31 mg/l would be expected to sit around the 25 step, between 0 and 50, 100 would sit at the start of the slightly hard band and 250 in the hard band. The pad shows steps, so it cannot tell 16 from 31, and it cannot say which zone you are in. A strip result is not a legal sample.

The area figure is an average worked out from a whole zone's 2024 calcium and magnesium results, so your own tap may sit above or below it, as Lomond Hills at 55.55 mg/l and Lomond Hills Borehole Mix at 141.90 show. The hardness pad is the one that matters here, and a step well away from what your zone's figure suggests would indicate that your tap differs from the zone average. Best pack: 20 strips, enough to read your kitchen tap on a few different days, £5.99 (or £10.99 with a bacteria test), with free 2nd Class delivery on every order. See the kit

Your Scottish water hardness questions

Does Scotland have hard water?

In places. By our count 23 of the 277 zones in the 2024 table are at 100 mg/l or more, many of them islands by their names. The other 254 are under 100.

Is Scottish water hard or soft?

Mostly soft. 214 zones sit under 50 mg/l, which Scottish Water's factsheet calls soft.

Does Scotland have hard or soft water?

Both, with soft far more common. The 2024 table runs from under 5 mg/l to over 340, so check your own zone.

Sources

1. Scottish Water, Water Hardness Data 2024 (hardness as mg/l calcium carbonate from 2024 average calcium and magnesium results by regulatory supply zone; the zone figures are Scottish Water's, the banding and counts are ours; undated; read 29 October 2026), listed on its water quality publications page (newest hardness table, described there as 2023 results; undated; read 29 October 2026).
2. Scottish Water, Water Quality Search (postcode search for your zone and hardness data; undated; read 29 October 2026) and Water quality (all water comes from rain, surface water supplies most customers, a few get groundwater; undated; read 29 October 2026).
3. Scottish Water, Factsheet 12, Hardness in drinking water explained (no regulatory limits; six hardness bands; raw water sources and boreholes; temporary hardness and boiling; effects of hardness). The file name carries 2020 and the factsheet may be out of date; undated; read 29 October 2026.
4. WaterKit, Water Test Kit (20-in-1 strip, 30 to 60 second read, 20 strips £5.99 or £10.99 with a bacteria test, free 2nd Class delivery on every order) and results portal (hardness steps 0, 25, 50, 100, 250 and 425 mg/L). The reading of the chart steps against Scottish Water's bands is WaterKit's own.
5. Coffee Forums UK, Would you use a water filter in Scotland? (a forum poster's account; one person's description, not checked; seen 29 October 2026).

Contains public sector information licensed under the Open Government Licence v3.0.