The reason for concrete is because my father used steel and 20 years later it rusted out from the inside and was a mess to replace. I believe his was corrugated galvanized culvert pipe. I hadn't thought about plastic. I need to do some homework to get pricing and establish the required size.

I will do the bucket test with my material but based on the mounds of white clay on another property I own and how it turns nearly to concrete when wet I expect the white clay will work better. When I clear the trees and strip the top soil I hope to find a vein of good stuff under the pond area.

I have dealt with heavy construction for 30 years and got the idea overseeing storm water management pond construction. Although these are for flooding and short term water retention the mechanics seem to be designed for permanent ponds or at least it seems that way. When I went searching for the concrete pipe I was amazed how much is out there at excavator yards where I assume they accumulate extra pieces due to redesigns and misorders.

The main concern is if I can stack this pipe vertically to 12' for the overflow, can the seams be sealed and what I need to do at the base so there is little to no settlement. One thought is to embed as much as possible within the dam where the top few feet is all that is not supported or in open water.

Any other thoughts would be appreciated.

Thanks,
Tom