What is a camper without some water for a brief shower after a day out in the woods? Not sure, but I wanted to have water on mine, so I added a plumbing system.
Custom made cargo carrier allowed me to use some space for a water tank, pump, and the rest of the plumbing.
The tank is made of clear plexi, to fit the allotted space, it holds 18 gal of water, enough for 15 minutes of continuous flow, enough for two frugal showers.
Inside the tank I have a full-metal fish tank heater, 100w for a max of 110 degrees F temperature, connected to an outside thermostat. Also I put a pressure relief valve, and four baffles to reduce sloshing while driving.
From the tank, I have a 12v water pump, pressure activated, connected to an outside quick connect shower. All it needs is one of those pop up shower privacy tent, and is good to go.
Because of the adhesive used to build the water tank, I do not plan to use the water for drinking or cooking.
I must mention a huge disadvantage of this is the fact that the water tank with its heater are inaccessible at any time, they are sandwiched between camper and cargo carrier. If, and when, I need to service any of them, I will have to lift the camper off the trailer.