Hi porchgirl, I've love to tell you this but then I'd have to kill you. (That's a joke! Can I do that on a professional forum???) The drainage systems is simply a gap under the wall.. so it is hidden. Yes bugs can get in here - just as they can crawl under a door. But typically flying insects (which is what we are really trying to keep out) don't come in here. It has not been a problem for us. Cypress is a light yellow wood. Putting a clear coat on it will make it as light as possible. We tend to try and brown it up a bit. Your local lumberyard should be able to order cypress for you. Good luck with your project!