South West Water serves 1.8 million customers across Devon and Cornwall. The region's granite geology produces naturally soft water, among the softest in England.
At 80 ppm on average, South West Water ranks as slightly hard water.
See how it compares across the UK in our 50 softest water areas ranking.
Common questions about South West Water water hardness
How do I check South West Water hardness by postcode?
Enter your postcode in the checker on the WaterHard.uk homepage, or find your district in the table above. South West Water serves 129 postcode districts across Devon & Cornwall, ranging from 27 to 138 ppm.
Is there a South West Water hardness checker or map?
South West Water publishes water quality data by postcode, but it can be scattered across PDF reports. WaterHard.uk compiles it into the searchable table above so you can find your district's reading in one place.
How hard is South West Water water in my area?
It depends on your exact postcode. South West Water supplies range from 27 ppm to 138 ppm, averaging 80 ppm (slightly hard) across 129 postcode districts in Devon & Cornwall. Use the table above to find your specific district.
Is South West Water water hard or soft?
South West Water averages 80 ppm, classified as slightly hard. Most households on South West Water see little to no limescale build-up, though individual postcodes can vary, so check the table above for your district.
Free Hard Water Action Plan
Enter your email and we will send the fixes that actually work for your hardness level, plus what to skip.