22' Safari has two options for filling the water tank. One method is using the outside fill spout. A garden hose, fill bucket, etc. will work for this. The other method is when the trailer is hooked up to a trailer park faucet. I must open a valve to allow water to flow and fill the tank. I remove the exterior fill spout cap, which allows the spout to act as an overflow, and I can hear the water spilling onto the ground when the tank is full, (even sitting inside the trailer). I then close the gate valve, put the fill cap back on, and I'm good to go with a full tank of fresh water!