Repairing a pond dam.

aarolar · Dec 4, 2016

I have a large pond on the back of my property that has been busted since I bought the place. It busted at some point due to beavers blocking the run around and now I have a 15' wide by 15' deep hole missing in the dam. What is the proper way to repair this what equipment would it involve. Could I make any progress with my MX4800 if I had dirt brought in considering I have unlimited time avaliable?

EddieWalker · Dec 4, 2016

Did the beavers block the overflow and then the water in the pond went over the dam? Or did the beavers dig out their home into the dam that resulted in the dam failing? The reason I ask is that one of the biggest causes for dam failure is from beavers digging tunnels into the dam and weakening it. I kill every beaver that I see, as soon as I see them. Before fixing the one bad spot, you need to be sure that's the only bad spot.

As for fixing it, your tractor should be fine. Just dig a ramp going down to the bottom of the hole on both sides, they with your front loader, start filing it up again in layers and drive over it with your front tires to compact it. Your front tires with a load of dirt in it will give you better compaction then a dozer will on tracks.

aarolar · Dec 4, 2016

EddieWalker said:
Did the beavers block the overflow and then the water in the pond went over the dam? Or did the beavers dig out their home into the dam that resulted in the dam failing? The reason I ask is that one of the biggest causes for dam failure is from beavers digging tunnels into the dam and weakening it. I kill every beaver that I see, as soon as I see them. Before fixing the one bad spot, you need to be sure that's the only bad spot.

As for fixing it, your tractor should be fine. Just dig a ramp going down to the bottom of the hole on both sides, they with your front loader, start filing it up again in layers and drive over it with your front tires to compact it. Your front tires with a load of dirt in it will give you better compaction then a dozer will on tracks.

I'm not sure Eddie this pond has been busted for probably before I was born I bought this place from a friend of the family and dad says he can remember sneaking into it to fish when he was a boy. The fellow used to farm this place and he may have busted the dam out because the beavers kept flooding his crops there really isn't a clear story there and it's pretty grown up. I plan to start clearing it up as soon as I get my loader and grapple around the first of the year.

I assume I will need clay to fill it back in with and just work it in layers like you say.

TripleR · Dec 4, 2016

Pretty much as mentioned, but be sure to install a proper overflow pipe and depending on the size, find a way to keep the water out until finished. And based on our experience you are sure going to need unlimited time to properly fill and pack it. We had to ponds "blow out" that were professionally built when they got filled too son after the build due to excessive rain.

Be prepared for it to take much more dirt than you think.

aarolar · Dec 4, 2016

What options do I have for keeping the water out while I repair it? This could be my biggest roadblock due to time and money restrictions.

bindian · Dec 5, 2016

I'd clean out the busted section to get down to clay with an excavator. The years you are talking about put a lot of sediment over the opening. Leaving it could give you a weak "layer" separating the original core trench clay from your "repair"clay.
I'd also notch into both sides of the opening to give it a tongue and groove shape. Kinda like a splice overlap when looking down at the dam.

Pack it down as Eddie mentioned above. I know, as I have had the same pond fill before the dam was finished and then again during remodeling. Eddie's method for packing is what I used. So far the dam is holding unfinished, with a foot of water going over the spillway and four spots over the dam, last Saturday!

Get a Honda water pump to keep the water down. I bought a Honda 2 inch pump in 2012 (when I built the pond) and now have over 225 hours on it with no problems. Be sure the pump and engine both are made by Honda.
hugs, Brandi

TripleR · Dec 5, 2016

aarolar said:
What options do I have for keeping the water out while I repair it? This could be my biggest roadblock due to time and money restrictions.

We used a gas powered transfer pump and left it in place covered up when not in use. On one, we borrowed a diesel irrigation pump from a farmer friend.

Like Brandi, we prefer an excavator, but it can be done with a tractor, some method of compaction is essential.

Xfaxman · Dec 5, 2016

aarolar said:
What options do I have for keeping the water out while I repair it? This could be my biggest roadblock due to time and money restrictions.

Setup a temporary siphon:

D2Cat · Jan 14, 2017

I would get some bentonite to mix in with the fill material. You can get in bags at many farm/feed stores and some locations you can buy it bulk.

If you don't have good tight clay you could be facing a leaking pond after all the work is done! The bentonite will help that problem.