12 postcode districts testedWater quality in South West England
According to TapWater.uk's analysis, South West England scores 9.5/10 for drinking water quality in 2026, based on data from 12 postcode districts. Water quality across Devon, Cornwall, Somerset, Dorset and Bristol. Supplied by South West Water, Wessex Water, and Bristol Water.
9.5 / 10
12 areas tested · 1 supplier
Tap water in South West England has an average safety score of 9.5 out of 10 based on testing across 12 postcode districts. Water is supplied by South West Water. The overall water quality is good. Data is sourced from the Environment Agency and water company testing via the Stream Water Data Portal.
Cities in South West England
Average water quality score by city.
51mg of limescale minerals in every litre, on average across South West England
South West England water is soft
Hard starts at 180 mg/L, very hard at 250. Hardness varies by area; check your own postcode for the reading where you live.
River health around South West England
2 of the 23 rivers and waters that South West England drains into are rated good or high by the Environment Agency. All of them fail the chemical test, as every river in England does, because of long-lasting pollutants such as mercury and PFOS. This describes the rivers, not your tap water.
| River or water | Ecological health | Postcode districts |
|---|---|---|
| Cam Bk - source to conf Wellow Bk | Poor | BS39 |
| Frome (Brist) - Bradley Bk to conf Floating Hbr | Moderate | BS1, BS2, BS5, BS6, BS7, BS8 |
| Plymouth Tamar | Moderate | PL1, PL2, PL3, PL4, PL5, PL9 |
| The Malago - source to conf R Avon (Brist New Cut) | Moderate | BS3, BS4, BS13 |
| Uphill Great Rhyne - source to conf R Axe Estuary | Moderate | BS22, BS23, BS24 |
| Bristol Avon (By Bk to Netham Weir) | Moderate | BA1, BA2 |
| Exe (Creedy to Estuary) | Moderate | EX2, EX4 |
| Trym - source to conf R Avon (Brist) | Moderate | BS9, BS10 |
| Banwell - source to conf R Banwell Estuary | Moderate | BS29 |
| Brislington Bk - source to conf R Avon (Brist) | Moderate | BS14 |
| Chestle Pill | Moderate | BS11 |
| Chew - conf Winford Bk to conf R Avon (Brist) | Moderate | BS31 |
Showing the 12 lowest rated of 23. Environment Agency classification, 2025. River health across England
Questions about South West England water
Is tap water safe in South West England?
Based on our analysis of 12 postcode districts in South West England, the average water quality score is 9.5/10, which is safe. Water is supplied by South West Water.
Which area has the best water in South West England?
PL9 (Plymouth) has the highest water quality score in South West England at 9.5/10.
Which area has the worst water in South West England?
EX3 (Exeter) has the lowest water quality score in South West England at 9.1/10. Check the postcode page for details on specific contaminants.
Is South West England water hard or soft?
Water in South West England has an average hardness of 51 mg/L CaCO₃, which is classified as soft. Hardness varies by area — check your postcode for exact levels.
Who supplies water in South West England?
Water in South West England is supplied by South West Water.
Data sourced from the Environment Agency Water Quality Archive and water company testing via the Stream Water Data Portal. See our methodology for how scores are calculated. Reviewed by the TapWater.uk research team.