That's why they offer bypass valves in some of the better CAI's like those from AEM. They open if the car goes through water to allow the engine to draw air and not water. Most people though, use cheap CAI's they buy on E Bay for $50, and not the better, but more expensive AEM parts. Mine was an E Bay cheapie I got for $50, but it was supposed to be an experiment to see if I could get to 60 in less than the 12 seconds it normally took.