Severn Trent Water water hardness
Ranges from soft to moderately hard across the supply area.
Severn Trent Water supplies water ranging from soft to moderately hard across its area, so the figure for your own postcode is worth checking.
Most of the water we supply ranges from soft to moderately hard.
Severn Trent Water, on their own website, source — checked 2026-08-24
The widest spread of any UK supplier: Birmingham draws largely on soft Elan Valley water from mid-Wales, while groundwater sources further east are harder. Severn Trent's own factsheet describes the supply as ranging from soft to moderately hard, so never generalise across this area — the postcode checker matters more here than anywhere.
Correction, 2026-08-24: We previously showed 'hard'. Severn Trent's own factsheet says their supply ranges from soft to moderately hard, so the claim was reduced to match.
What this means for your home
Your water is moderately hard — worth protecting the boiler, not much more.
Scale will build up slowly on heated surfaces. A scale inhibitor on the boiler is proportionate and inexpensive, and some manufacturers start asking for one around this level. A softener is still difficult to justify on cost. Test your own tap before deciding — at this level the exact figure matters.
Where Severn Trent Water supplies
Regions: West Midlands, East Midlands, Yorkshire and the Humber
Counties and areas: West Midlands, Warwickshire, Leicestershire, Derbyshire, Nottinghamshire, Staffordshire, Gloucestershire, Shropshire, Worcestershire
Supply boundaries do not follow county boundaries, and several companies may supply parts of the same county. Always check your own postcode.