Hi all,

I have owned this property for almost a year now. There is a damed pond, almost 2 acres in size. It was built in 1966. Here is an aerial that I had taken this past fall


There is an iron overflow pipe built into the dam which spills into a small crick. The as-built drawings from 1966 (very faded)show a vertical section of ~15 feet with a horizontal section angled at ~27* and 110 feet long. I believe the pipe is old gas line pipe, as at the outlet, it appears to have a wrapping on it. This is/was very thick pipe. It is hard to imagine that it is leaking but the previous owners had a sink hole filled a few years back. Now in the same location, I noticed a small sink hole forming last fall. Pretty small, could maybe fit a basketball into the size of it. Now that the snow is melting, I've noticed that it has gotten bigger.

Maybe it's just the dirt settling after a few years, but I'm worried that the pipe is leaking and washing out below. Unfortunately the previous owners are no longer alive and I can't get much history.

I'd like to address the problem with a solution that will work. But as you all know, as a new home owner, funds are a major issue. I'm an engineer, I'm handy and I know a lot of people with a lot of skills. I really feel this is something that I can fix, I am just not sure what the best route is.

The previous owners did get a quote to have the existing pipe replaced, like for like, at over $20,000!! No thanks, I'll drain the pond for that money.

Here are some pictures
A view at the typical fishing location. This is also where the emergency spillway starts


This shows how steep the banks are, all around the pond.

A view of the dam. It's very big and VERY steep. I need to find a way to safely mow this...


A view from the outlet, looking up


Inlet and trash rack


Outlet


You can see the outlet has some sort of wrap on it. You can see the corrosion on the outlet, but this is exposed to air and water, so I'm not overly concerned about this part


Another view of the dam


So how can I fix or replace the spillway? Replacing it with another deeply buried pipe seems pointless to me. At some point, steel will rust or the plastic will crack or a weld/joint will crack and I'll have the same issue again...many years down the road.

My thought is, why not put a vertical outlet near the top of the dam, and run it angled down, laying on the dam hillside. NOT buried, and exit at the existing spillway/outlet? This would require minimal excavator work and would allow the pipe to be above ground, for easy inspection and cheaper installation. Will the pipe look ugly sitting in the open? Sure, but will it be 10x cheaper to install and should be just as effective, I think so...but that's why I am here, and that's why I'm asking.

Here is a terrible sketch, but hopefully it gets the idea across....

So, what about my idea? What about my other options that I might not be aware of? I did get a quote to have the existing pipe relined and it was close to $20,000 as well. This has to be a low budget build for me. I'd like to do it myself.

Oh, I believe the outlet is ~12" and the inlet is a little larger, I can't remember off the top of my head.

The previous owner had a company run a camera a few years back, they said it looked fine. He said it was low quality and they probably missed whatever the issue is. But, he has since passed away so I'm out of history.

What are my options and THANK YOU for the help!!