I have an old pond 50+ yrs. It has a conventional overflow system 12"-14" Dia. culvert. Is there a way to convert this system into a bottom draw. I was thinking I could run 12" HDPE down to the depth I wanted to draw from and either make a good seal at the junction of tin intake, or run 10" down inside the original and attach it to the intake tube. Is this a possibility or wishfull thinking? I will eventually have to put in a new system but wanted to do something on my own, soon.

Thanks, Fishhead

Anyone? :rolleyes: Just wondering if this is possible?

I have no experience with this, but am willing to give a "Plumber's Son" (Grandson, too) opinion. I believe it should work IF you can get a good seal between the existing drain pipe and the new descending pipe.

Two things I would worry about: 1) reducing the outflow too much with resulting increase in water backing up during heavy rains if you have to use a smaller pipe, and 2) making sure the bottom of the descending pipe is clear/not stuck in or sucking mud.

Fishhead,
I like the idea of running 10" through the existing pipe. I would suggest running the 10" the full length of the existing pipe and cementing it in. Your existing corrugated metal pipe is probably starting to rust out. This would give it a permanent fix. Then go ahead with the siphon off of the 10"

zhkent, I didn't think about pouring cement down the drain to use as a seal. I guess the only thing that muddies the water with running 10" down the entire length is the fact that at some point my overflow does a 45 out to the spillway. There is no way I'll be able to make that corner.

There's a good 6" of water entering the overflow at this time so I will have to wait until we have some kind of drought, or make an over the dam siphon to draw it down.

I do have an emergency spill way that does in deed work. As we found out two summers ago after a 6" down pour in 3 hours. It trashed the pond for the year as it washed every corn cob in the county (seemed like) into it.

Thanks guys, I was thinking it should work but needed some reassurance. If I get it done this summer I'll take pictures so it can be documented and shared with others.

FH

I wouldn't be afraid to do the work now. The concrete will set up fine under water. Once you insert the smaller pipe into the larger simply tamp some old rags, hay or whatever back as far in & between the pipes as is possible. The smaller pipe will then take the water flow & you can tamp the cement in around it.

Fishhead,

I am in the process of replacing my overflow drain with a bottom draw siphon system and adding an emergency spillway. My contractor is recommending to dig out the old drain pipe and install the new system in a different location. My current drain pipe is rusted and is no longer usable. Another option I came up with was sealing the old pipe (versus digging it up) with concrete; however, this was more expensive than just digging up the old pipe since it would take special equipment to push in the concrete + cost of material. Another issue with packing the old pipe is unseen air pockets, although these impact of these was minimal.

In both cases the pond needs to be drained down to the level of the old pipe.

I’m a beginner at this, so there is plenty of room for me to learn, but, I will let you know how it goes.