[The Newell]

The biggest water user is dish washing. If you can learn how to wash dishes with minimum water, and are serious about watching your water use , the sailors calculation of A gallon, A Man ,A Day, works just fine. Navy style , wet down , wash with water OFF and then rinse the soap off.

The usual RV toilet is very efficient, so is not a big water user. TO do dishes with min water takes having a small bowl of hot soapy water , to scrub the dishes and a Quart pitcher to use to pour water over the cleaned but still soapy dishes ,, sort of like a Navy shower for your pots and pans.