South West Water (SWW) customers could be set to face an average of a £64 increase in bills over the next five years.
A draft plan from water regulator Ofwat proposed a 13% bill increase for people which would begin at the end of March 2025 until 2030.
It would mean customers would pay £12.80 a year more for the next five years resulting in annual average household bills totalling £561.
The water company said it would “review the draft packages proposed by Ofwat” and that it looks forward to a “constructive dialogue ahead of responding to the consultation”.
Ofwat’s report said the current average household bill for water annually was £497, the second highest in the country.
SWW had suggested an overall increase to £604 per year by 2029-2030, but Ofwat said the overall total should sit at £561.
The increase is intended to fund investment for improvements such as replacing leaking pipes and reducing sewage discharges into rivers and seas.
Ofwat said SWW was expected to also deliver a 58% reduction in storm overflow spills on 2021 levels.
This would be supported by a £750m programme of investment, the regulator said.
The draft decision also outlines proposals for a reduction in pollution incidents by 30% with an investment of £140m to prevent nutrient pollution in rivers.
Ofwat said in its draft report that SWW’s business plan was “outstanding”.
It said: “We have categorised South West Water’s business plan as outstanding as it allowed us to challenge the sector to deliver more for customers.”
A SWW spokesperson told the BBC: “We welcome Ofwat’s recognition of the quality of the business plans for Pennon Group businesses, underpinned by significant customer and stakeholder support.
“South West Water’s business plan for Bournemouth, Bristol, Cornwall, Devon, and the Isles of Scilly has been categorised as outstanding and is recognised as a ‘leading plan’.
“Having acquired Sutton and East Surrey Water in January 2024, Ofwat has assessed this plan as standard, confirming this plan is ‘generally good’.”
Water bill increases vary across the country.
Thames Water customers face an increase of £99 or 23% over the next five years, and Southern Water customers face a £183 rise, an increase of 44%.
The draft report is now open for consultation and responses are being asked for from customers, stakeholders and water companies before 12 noon on 28 August.
Ofwat said it expected to publish its final decisions on 19 December and that if water companies did not agree with the final decisions, they had two months from the date of publication to ask for an appeal to the Competition and Markets Authority.