Water somehow got in the car

So Helen rolled though a few days ago, we didn’t get any damage but my heart goes out to the people effected. The reason why i am here is because water got in the car some how, we had a tarp cover the car and tied it down really well but the water was high enough to almost touch the side skirt. (feet were drenched) So i am wonder if anyone has had this problem and if they know what needs to be fixed.