In CG's with only dispersed water faucets (each camping site deosn't have water) I just pull alongside the faucet and attach a hose to the faucet and fill my tank if we're going to be in the CG for a few days. This works really well in USFS and NPS CG's. If you can't hook a hose to the faucet or the CG has the old fashioned pump, then I just use a bucket and fill our RV using a funnel one bucket at a time. Takes awhile but it works!