What year?
Common water leak for 97s and up is through the firewall opening where the blower fan pokes thru. The foam seal between the HVAC box and the firewall deteriorates over time. Pulling the dash gives you access to the foam seal. Pain in the ass though.
Easier fix is to apply silicon sealant around the mating area where the blower pokes into the engine bay. I did that fix about 8 years ago, and it's still holding. Also, move the harness a bit, just above the blower. Water tends to drip off that harness, straight into the blower area.