I'm having about 140' of new 4" drain line installed to drain water from the back of my house to the street at the front, and will have it tied in to my pool plumbing to backwash my DE and/or drain pool water to the street also. I have the option of smooth or corrugated pipe, and while the corrugated pipe is less expensive, I get concerned with it clogging with DE and dirt. The guy doing the job says it's up to me, but the corrugated should be fine and I'm probably over concerned. Anybody have thoughts?