The owner of South West Water has returned to profit after rising water bills and a hot summer helped boost its sales by more than a quarter.
Pennon, which also owns Bristol Water, Bournemouth Water and SES Water, revealed the improved financial performance despite coming under fire for wastewater spills earlier this year.
The London-listed business told investors it made a pre-tax profit of £65.9 million for the six months to the end of September, swinging from a loss of £38.8 million the prior year.
Water revenues soared by 26% year-on-year, to £519 million, which it said was driven by tariff increases and higher demand over the hot summer months.
Water bills rose for many households in England and Wales from April.
This reflected higher prices for suppliers and to help pay for water firms’ investments into improving infrastructure and their environmental performance.
For South West Water and Bournemouth Water customers, average bills jumped by 32%.
Meanwhile, water usage among Pennon’s customer base was higher than the previous year, following the UK’s hottest summer on record, according to the Met Office.
Pennon said it was working to tackle pollution incidents happening on its watch, and investing in its services “as summers become hotter and drier”.
Pollution incidents in its wastewater network halved in 2025 compared with 2024, with storm overflow spills cut by about 45%, the company said.
It comes after the business agreed to pay £24 million in July over wastewater leaks following an investigation by regulator Ofwat.
The money is set to go toward investment and funding over the next five years.
