Well sure, but pressurized pipe can be tested with hydrostatic testing at fire hydrants. Smoke testing too if they're old school. If they are chasing down a leak, there is a good chance that they will just shut off water for a day over a city block or housing development while they cam the entire system.

Not to be contrary, but I'm sure that what ever instrumentation would be called for to cam the pipe would be the same to have one of these little robots in. If they were faster then tethered robots or you could let a swarm run through pipes, that might be the good cost/benefit.

I would like to see those tiny gimbled drones that are 3" that could fly through 4" pipe.