It would depend on the type of filter you have. I put in a Raycor water separating filter and it has lasted for years. I dump it often and it has not been a problem. I suffered with the old filters clogging at the worst possible time and now no problem. What type of filter are you using?
I always carry a shammy cloth - the kind you polish your car with - when I'm out on the water or in some situation where I might run into bad gas with water or muck in it.
Saved my butt once when I was on the east side of Admiralty Island with somebodies unfamiliar motor. Poor the gas through it and it catches the water. Most times a good filter is all you need - but a shammy takes up so little space it's good security. Especially if you are going to be refueling in some remote funky place.