Is this a fair deal, I guess it's pbr? More of a Keystone guy though. I know nothing, any comments welcome. [url]https://nh.craigslist.org/mat/d/roofing-metal/6666938506.html[/url] I'm in New Hampshire

I need to connect piping (e.g. black corrugated) to one of my downspouts to channel rain water away from a mulch bed and to the side yard. Problem is I don't have very much slope to work with, so about the first 1/3rd of the pipe will be exposed if I go with 1/4" per foot. This isn't too big of a deal because there will be shrubs concealing some of it, but the first 5' to 6' section will be visible. If I were to instead bury the entire run and have no slope at all for most of the run aside from the beginning and end, would this be a big deal? This would allow me to bury more of the pipe near the downspout. If I go this route, about an inch of rainwater would collect and sit inside the pipe at all times (unless it didn't rain for a while and dried out), but anything in excess of that would drain out the end come the next rainfall. I can't think of any reasons this would be an issue (maybe it would invite bugs/mosquitos?). Another idea, although probably not legal, is to discharge into a plumbing cleanout, which is less than 2' from the downspout. I imagine the sewage company wouldn't be happy about this, but it sure would be convenient. Figured I'd ask. Come to think of it, I guess that would allow sewer gases out huh? That wouldn't be good.