2001 4 Runner leaking water on the drivers floor board

I have a 2001 Toyota 4 Runner with the 6 cylinder engine, 2wd WITH a sunroof. About a year ago I started to notice the floor board in front of the drivers seat was getting wet when it would rain. The carpet right next to the kick panel on the left side of the floor board is where it is getting wet (near the left side foot rest). Earlier this week it rained and my drivers floor board was complete soken wet, worse than it has ever been. I pulled the carpet up to see if I noticed anything. I punched a small hole in the 2 plastic plugs in hopes to help drain the water but I would like to know what I need to check in order to fix the problem.

Thank you in advance for your help,
Ryan