Plan fresh water, grey water, pump flow, hot water and shower demand as one system. Water is heavy, so capacity should match the number of travelers and trip duration.
Fresh water capacity
Tank size should reflect drinking, cooking, washing and shower requirements without adding unnecessary weight.
Grey water handling
Sink and shower waste should be routed to a suitable grey-water arrangement that is accessible for draining and cleaning.
Pumps and pressure
The pump should match the expected fixtures and provide stable flow without excessive cycling.
Hot water
Hot-water systems add power or fuel demand, plumbing complexity and space requirements, so they should be included early in the design.
Maintenance access
Pumps, filters, valves and drain points should be reachable for inspection rather than permanently hidden behind cabinetry.