I check mine everytime I fuel up and have never had to drain it. When I changed my fuel filter at 11,000 miles it looked fine. I always try to get fuel at high volume stations (Flying J etc.)
It makes it easier if you clamp a piece of hose on the drain and run it a little below the bumper to catch the fuel. Only drain a couple of tablespoons if you have too. You don't want to get air in the system. I also use Power Service fuel supplement which takes care of water among other things. Walmart sells it. Hope this helps.
With any luck you'll never have to drain any water out although it's a good idea to drain a little fuel out at each PM just to keep the valve working. The number one reason for water in the fuel is getting bad fuel somewhere. The other reason is condensation in the tank, and that can be prevented by keeping the tank full when the motorhome is not going to be used for a while.