Pond Boss Forums INTRO Questions & Observations Pond Renovation

Hey folks, Iam in the process of draining my 5 acre pond. It is about 30 yrs old and the overflow pipe has seen its better days. The original pipe was corrugated and tar coated. My county ext. agent has recommended smooth steel for the replacement pipe. My riser pipe is 18" with a 12" through the dam. The dam is about 100 ft. wide at the base, with about 14 ft of water at the riser pipe.
Anyone used smooth steel instead of PVC ?
I hope to have the shallow end where the stream enters dug out because it has silted in over the years with about 2 to 3 ft of silt and mush that STINKS.
I have a 25 ft long cement wall that is 4 ft high for an emergency overflow, it runs over maybe 1 time per year.
Any thoughts or suggestions from experience will be appreciated...

I don't know about materials but collars are a must! If you don't have collars water will work its way along the pipe and you will eventually spring a leak. I had it happen to me even though

I told my contracter he must use at least one. Of course he did it his way and had to come out and repair the damage. He won't be building anymore ponds for me.

He built a smaller pond for me without a core trench. Again I told hime I must have a core trench. He did it his way and of course it seeps!

Added Info. the collars that Cecil is talking about are anti-seep collars. For metal pipe flat metal plates can be welded onto the pipe. Use at least two for long pipe runs. For PVC pipe they make 2'x2' collars with wood frame and neoprene rubber centers. The local Soil & Water Extension service may be able to help locate a source. www.aquaticeco.com sells ($30 ea) the neoprene anti-seep collars that I mentioned.

Water will want to naturally flow and push out along the outside wall of the pipe when it goes out of a pond wall esp if the water in under head pressure (depth). Flow along the water pathway will tend to increase over time if antiseeps are not used.