Move the car to high ground. Find a parking lot that's on a hill, better yet find a parking garage and park on an upper floor. A few hundred dollars in parking fees is worth it to prevent your car from being destroyed.
I'm suggesting a paid parking garage. As for a parking mall that had peoples cars towed in the wake of a catastrophic storm, they should be boycotted, they deserve to go out of business.During Harvey, some locals had the same parking garage idea but they went to a (free) shopping mall which had the police tow them off.