Do it all the time. Rather than driving with water in our tanks, we also simply fill empty gallon milk jugs with lids with water to pour into the bowl after each use. Easy, simple, and no need to even use the water pump! Just be sure to use only as much T-Paper as necessary and to add extra water once you're set up in a campsite. Helps avoid clogs when emptying the black tanks. Suggest you always make sure the black tank is full when you empty it as well. Creates a much better flow and also helps avoid a clog. Happy camping!