Not sure if you have driven the car during the storm or it has been static. Here are a few things I have come across over the years that could cause this issue.
I would start by drying out the footwell carpet thoroughly and then start troubleshooting all the various possibilities of where/how the water is entering one at a time. A fast way to dry your carpet is a carpet vac if you have one, then finish off with a hairdryer or heat gun. On completion and during every individual check, then recheck the carpet.
In extreme weather driving rain or surface water penetrating a door seal is a strong possible. I would check for a damaged or deformed door seal. This would be my first check. Ask someone to spray a garden hose around the complete door whilst you observe for leaks from the inside - feeling the carpet. Give the windscreen seal the same treatment, especially the lower section of the seal. Ricardo has already mention the windscreen scuttle drain. A leak in the heater matrix system is also a strong candidate for water in the footwell, before drying up the water does the water smell like coolant or normal water? If it smells like coolant, you probably have a leak in the heater matrix radiator core or hoses in the system. Blocked air-conditioning drain hose. Hope this helps

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