The water that drips or flushes from the front windshield onto the plastic cowl will end up in the cavity where also the interior ventilation fan is located. And  of course the water needs to go somewhere. Otherwise it will eventually seek its way down  and drip on the CEB or on the ecu's located in the passenger footrest area.

The cavity under the cowl has a drain. Water will seep out easily. But is autumn leaves clogged the drain or keep it moist for a long time, the inevitable thing will happen.

Here is what it look like....