From April, households who receive both water and wastewater services can expect average bills to rise by eight per cent. The increase is part of the company’s ongoing investment strategy, with Southern Water committing £8.5 billion to upgrade infrastructure between now and 2030. "This is the biggest ever investment in our water infrastructure, and it’s essential to keep services reliable and sustainable long term. Last year, Southern Water introduced a 46.7 per cent rise for average household bills after a decade of unchanged charges. The new eight per cent increase is part of a strategy to spread further rises more evenly across the next four years.