Sounds like it's time to take an old farm pickup (or bigger) and paint
the bed with a thick coat of trailer topping to seal it up like a small
swimming pool and then "wash it" until its full then park it by
the livestock. If the water police come by just tell them you followed
the regulations and only washed the truck for 6 hours and you did not
want to waste the water that collected in the bed because you are very
sensitive to the drought situation. >:-}
Don Huston