Plumbing diagrams for your coach are available at this link
Looks as if the leak be in the piping that runs between the water heater and wet bay, on the driver side of the coach.
Should not be too hard to find. Put some water in the fresh water tank and run the pump. If it does not shut off, that's a clue the supply side is leaking. If the pump does shut off and not run again (without opening a faucet or drain), then check the tanks by filling them, starting with the hot water heater.
This happened after the coach was exposed to freezing temperatures without being winterized, yes?