You're a bit all over the shop in that answer.

Our concern here, and that of many people in the area, is total water usage per household - and to a large degree water usage for washing, showers, and toilets is a small fraction of the total usage - and one that can be ignored as most people have grey water capture (as do well planned and infrastructured cities).

Water used inside the house runs out to water food, shade, animals, etc. and that use can be deducted from the water that is required for those uses.

Energy is no great cost, it comes from the sun - both as electricity via panels and directly as heat via solar hot water systems.