Not saying drilling a hole is a bad idea. Suggestion reminds me of a crazy experience I saw in early '70s. A cop and a mechanic get two sheets to wind in a bar. Cop starts complaining,says his brand new car gets tons of water after every rain,it collects in wells on either side of trunk. Cop asks mechanic to take a look and see what can be done.
The two walk out side,no one pays much attention. All of a sudden,two pistol shots ring out. Bottom line,mechanic asks cop for gun,cop gives it to him. Mechanic shoots a hole on each side of trunk,says no more water will collect there.:laughing:
I don't have much of a clue, but I'd probably drill a hole in the middle of the carport to see what happens. If water starts flowing up out of the ground maybe you have a spring, or there's a drain pipe of some kind that's busted and is leaking under pressure.