The problem here is financial illiteracy - the alternative to paying dividends isn't that the same money all gets spent on the water network. Large scale investment is rarely funded from general revenues as it'd require spending years accumulating a huge cash pile that sits around doing nothing, and governments see such piles as pigs to slaughter. So the alternative is that the government borrows the money and then has to pay interest on it. From your perspective the UK "wastes" 8% of its spending on interest payments, and it's rising rapidly, but of course if it didn't pay interest then nobody would lend it money and all funds would have to either come from taxes or via inflation.