We purchase water in Gerlach, stored in dedicated 35 - 50 gallon containers. Use transfer pump to load one RV (mine) which has an external shower with an evap pond / system set up for camp use. Generally there is about 5 to 10 gallons of unevaporated water at end of event (yech!) which is pumped into the graywater holding tank and taken off-site.
3:15 & Cosimo