This is great site, I wish I had found it earlier -I really could use some sage advice.

I'm located in SE new England. I have a 100 year old ice pond, 90 x 150, 3 to 4 ft deep, stream fed, earthen dam with a small concrete wall and chamber in front of a buried 14" clay pipe outlet about 15 ft long that flows to a small stream.

Fifty years ago a concrete plug was poured in place of the stop logs creating a fixed weir. There are large trees close to the pond and dam. The dam includes a buried rock and concrete wall.

I recently inspected the clay pipe with a drain camera and confirmed the interior is in poor condition and roots are intruding at some of the joints. Much of the exposed concrete is spalling or worse. It appears there imay be minor leakage around the small concrete wall.

The pond does not freeze thick enough for safe skating now.

I'm looking for a low cost way to extend the life of the dam.

Since there are no stop logs and it's too shallow for a siphon, I need to plan on working with water in the pond.

I have considered these options, but would appreciate suggestions and comments:

1. Extend the existing concrete wall with tremie concrete. Install a concrete trench from the existing weir across the dam to a slash spillway before the stream.

Will the water in the trench be subject to freezing and stoppage if the flow is low?

2. Insert a plastic pipe inside the clay pipe from the downstream end, then seal the gap between the plastic and clay with concrete. The clay pipe has a 22.5 bend near the downstream end. I would still extend the concrete walls.

What kind of plastic would be strong and flexible enough?
Will tree roots crush the plastic pipe?

TIA for any suggestiions, comments or referrals.
Is concrete the best material to seal the inlet gap between the clay and plastic pipe?

Last edited by 964Puller; 08/09/13 02:26 PM.