330ci Dinan Intake install, need advice

I have a 2002 330ci with a Dinan airbox and there is a lower tube that comes out of the airbox and taps into the brake duct. I have an m3 bumper with the 3" air opening and wanted to turn it in to sort of a custom velocity stack effect by connecting the tube right up to the opening. I have located the custom silicone reducer couplers I would need to make it a clean install, but I'm worried about potential sucking water up into my intake. I had thought about taking an intake water sock and cutting out a section to go in between the duct hole and the coupler, just looking for insight or advice from anyone who has an idea. Thanks!