Altho this is not what the intended purpose is for, maybe this engineering will ignite "out of the box" thinking...
When I spoke with Mike Otto about a thru-dam drainpipe, we also discussed a filter at the intake (pond side) of the drain. Our discussion was based on 6" dia PVC. He said that his normal procedure for a strainer is to put a 90 degree elbow on the intake of the pipe, pointing upward (don't glue the 90 to the horz drain pipe...just twist it on snug using the natural pipe-fit to hold it together. This way the entire strainer assy can be removed, if need be, to by-pass an unexpected severe clog). He then takes a 5' - 6' section of the same pipe and drills 3/4" -1" holes all up, down, and around, about 1" spacing between holes (I think he said that the 1" will allow the leaves to get thru...had probs with .750" choking with leaves). He attaches this to the up-ward facing 90 and puts a cap over the top of the filter pipe. He pounds in a T-bar next to and parallel to the vert strainer pipe. Attach the strainer pipe to the T-bar with removeable pipe strap, galv. bailing wire, or some similar non-corrosive "reasonably easy to remove" fastener.
So...I share this with my contractor who, as always, listens intently allowing me to present my case. "OK...yep....yep.....uh huh....yep" When I finish, he looks at me and says "and....?". That's it (I think). He responds by adding: I do the same type thing, but we add a little more. He drops a vert pc of 12" or 15" corrugated pipe over the entire vert PVC strainer described above. The corr pipe has the same gazillion holes drilled thru it. Then they drop gravel into the corr pipe, filling the gap between the PVC and corr and a foot or two over the top of the PVC cap.
It makes sense to me. The only thing I did not address with my guy was the "not gluing the 90 to the drain" decision. I presume that he does glue it, assuming there should never be a clog scenario with his "double filter" design.
I like Mike...I like my guy, too.
