Ofwat backs £3.4bn water upgrades, so five firms' bills could rise from 2027

Water regulator Ofwat has provisionally approved £3.4bn of extra investment for water companies in England and Wales. The money comes through a new "Cost Change Process", which lets companies apply for funding where costs were unknown or uncertain when Ofwat set bills for 2025 to 2030 in December 2024.

Companies asked for £4.3bn. Ofwat has provisionally allowed £3.39bn, including about £1.2bn to protect existing services and assets, £477m to support growth such as new housing, and £34m to deal with PFAS, also known as "forever chemicals".

Whose bills are affected

Only five of the 13 companies involved plan to add the cost to bills between 2027 and 2030. The others will spread it into the 2030s. Here are the total additional costs over 2027–30:

• Southern Water: about £80 in total, including £43 in 2027/28 and £37 in 2029/30
• Wessex Water: £11
• Thames Water: £8
• Severn Trent: £8
• South East Water: £1

These figures are provisional. The consultation closed on 24 September 2026, and Ofwat expects to publish its final decisions in December 2026.

What this means for you

Nothing changes on your bill this year. If you're a Southern Water customer, plan for a noticeably higher bill from April 2027, on top of any annual change already agreed.

Ways to cut your water bill

• Consider a water meter. Installation is usually free. If you live alone or use little water, paying for what you use can be cheaper than a bill based on your home's rateable value.
• Check for help schemes. WaterSure caps bills for some metered households on certain benefits. Every company also runs a social tariff for low-income customers.
• Ask for free water-saving kit. Many suppliers give away shower heads, tap aerators and cistern bags.

Sources: Ofwat, Ofwat: Cost Change Process