plumbing leak

Have a 1997 21L Hilo. When hooked up to water source, water poured out underneath the side of the trailer that the sink and water heater are on but there was not much water inside the camper. So, I can't determine where the leak is. Thinking of removing the water heater but looks like a major...

A leak between the water heater, walls, and bath. All piping seen looks good. I am trying to see where else it may be. Pooling from the bath area and under those walls.