There are a few places, besides the w/s seal that are also prone to leaking in rainwater. Check under the hood by both front hood hinges. There is a hole in the channel there where the water is supposed to drain out. It gets clogged and the water runs back into your floorboards.
Also there rainwater does run down the front of the firewall. Have seen where those miserable black rubber plugs, where the vacuum lines and the wiring runs through, get dislodged and will leak a lot of water in.
Then there are the sunroof drains, and the rear window seal, both of which can put enough water into the cabin to get the front floorboards full or water. Don't overlook clearing the trunk drains either. They require regular and frequent cleaning, or you will see water coming into the rear floorboards, adn soon enough it will be under your feet.
Have fun.