Leaking when it rains? Where in the hell is this water coming from?

To be honest, I have no idea how to get into the Cowl. I can barely even see what is going on from the top vent. Are we supposed to clean it out somehow?
As for the leak, I got under the dash and looked, the water is coming at the bottom corner of the windshield. Or something very near the windshield. So that is not the cowl, correct?