Privatize the profits; socialize the losses. Good old capitalism.

You pay if your toilet leaks, they can be held to the same standard. They should have noticed their water meter reading crazy numbers and deciding to inform the utility company and investigate their pipes.

Normally the portion of the pipe on your property is your responsibility. It isn’t the city’s faullt if someone is too dumb to maintain their property.

Pay up, unless you’re willing to declare bankruptcy to shed the debt (which I doubt would be allowed).