"Sir John Armitt told BBC Radio 4’s Today programme: “By 2050, the Environment Agency and the water companies believe that about £50bn needs to be invested to get sewage overflows down to an acceptable level."
Right. My local water company, South West Water, is paying £112M in dividends this year. There are ten water and sewerage companies in England, if we assume they're all about that level then that is £1.1bn per year. Counting 2023 and 2050 there are 28 years to go on that clock, so there's ~£31bn right there.
I'm sorry, water companies should not be paying dividends at the same time as a) breaking the law over sewage discharges and b) arguing that bills need to go up massively to pay for fixing that. They've got the money, they need to (be forced to) spend it on regulatory compliance before kickbacks to shareholders.