I may just insulate our outdoor shower when we travel to freezing areas instead of adding valves which could cause leaks. I am probably in the minority of campers who uses an outdoor shower with hot water nearly daily when camping for hand washing, rinsing off sand and shoes, and cleaning larger boiling pots. However I am careful about what gets drained to the ground. I actually prefer the street side location because we keep a carpet mat down under the awning and do not want a wet mess around our door. Most of our public and private RV parks in this area of the US have no dedicated dish washing sinks. I once asked why and was told they were tired of cleaning up behind campers who left the sinks nasty and plugged with food, hair, and such.