Every time it rains I get a little (or a lot) of water coming thru the bottom of the garage door, even with a rubber seal. A real problem when my lumber on the floor gets wet.
I now pour a line of sawdust (its free and I have plenty of it) against the inside of the garage door before the rare rain here in southern California. The sawdust immediately soaks up the moisture so it doesn’t create a flow. I just sweep it up the next day.
-- Life so short, the craft so long to learn