Hello. New user here. I have been reading the forums here for the past few days and have found a tremendous amount of knowledge. I thought maybe I could get some more advice and opinions of what to do at this point. I have an erosion problem on the back side of my dam and am curious as to how to begin to fix it. It’s a small spring fed pond, maybe half acre, fed by roughly 10 acres of steep hills of runoff. I’ve owned the property for 2 years now and have always had water running over the top of the dam. There is large rip rap in the middle of the dam inside the pond to below water line, along the top of the dam, and all the way down the backside to the base. I DO NOT see any drainage pipe, and my neighbor (who sees my pond from his house) hasn’t seen one even at it’s lowest point. The soil has started eroding from the top rap along the back side. No erosion on top though. I’ll attach pictures since this is getting too lengthy. Thanks everyone

Welcome to the forum Josh!

Ponds are best suited with a drain system that avoids the flow of water over the dam. Like a through pipe, the cheapest alternative, or the sophisticated siphon drain.

You could fight the erosion by packing in some proper clay and adding rock as needed, OR even have a concrete overflow installed, but a pipe system through the dam will be best, Then, the "water over the dam" only happens during extreme rain events.

How old is the pond?

Any signs that the previous owner has made erosion repairs before?

I would guess the pond is 20 plus years old. The only erosions repairs noticeable would be the added rip rap along the center of the dam. I was unaware (mostly unobservant) about the large rocks until now.

We have had unprecedented rainfall locally here in east Tennessee so we are at this "extreme rain event". But even with no rain, there is flow over the center of the dam. It is a spring fed pond and has a stream formed 50 or so yards beneath it. so there is always water in/water out. I just don't like it going over the dam. Now that erosion has started I'm afraid nothing will stop the erosion unless I divert water out elsewhere.

I too agree with the drainage statement. I can not believe there is no drainage system other than allowing flow over the center of the dam. That just seems like a huge no no.

I believe I will make a cut into one of the side edges of the dam and install 40' of 12" double wall plastic drainage pipe. Then I can add rock and clay to the center. One day I would love to put in a siphon system but I would need to do some thinking, ordering, and would just take a little more time (that I'm short of).

The pictures show correctly on my phone, but sideways on a desktop. Pictures were taken with my phone in the upright position. Any help moderators?

All your pictures "pop out" oriented correctly for me.

I would say that you have, surprisingly, little erosion damage if the 20 year old pond has always overflowed the dam. I would still want to improve it as you do.

It looks like a real nice setting!

Welcome Josh. I'm not a pro and you may already know all of this, but a lot of ponds just have earthen spillways, that I think most people call the emergency spillway. They should be cut into the natural soil on the hill side at the end of the dam and not the dam it's self. I would start with doing that first. You'll want a good emergency spillway even with a good pipe drain system. Then maybe you can wait a little longer till you have time to do a siphon system.

Welcome Josh
I have a 5 acre pond and I have 2 24” double wall pipe for my spillway. As was said before have it on the hill side of the dam and have rip rap behind the spillway to keep the erosion down and away from dam. Some folks concrete in a spillway around here