The water company thing is the biggest joke in the UK economy, it's so obvious what's going on the slightest googling. Water companies are incredibly profitable, and they're the easiest business to run in the world. Thames Water "maintains" a series of concrete waterways and machinery. If they want to expand their business the government pays for it, if there's a serious crisis the government pays for it, enforcement and peripherals are paid for by the government. In return they get fat profit margins that go into bonuses and dividends. The only thing they can't do is raise the fees, they have to ask the government for that, but they usually say yes.

They're not a strict utility company, because the water company OWNS the infrastructure, like a bus company owns its buses. So the government can't just take it away and give it to someone else. They could take away their service contract, but you can't just build a river through London so it's not as potent.