Dam repair

Corfit7: We had the same problem about 15 years ago on one of our stock dams. To fix the problem was a very big job. We had to terrace the hill sides and devert the run off away from the dam. Once the terracing was done we had to fence the dam off from the cattle because they were adding to the erosion. Then we had to put ABS pipe in which fed a stock tank away from the stock dam. Was not cheap. Good luck hope you have help.

PS: We also had to replant the grasses around the dam. It was four years before we could let the cattle back in to the dam area and do away with the stock tank..

Corfit,

From my experiences with stock dam, you would probably be much better off going to a fresh water source if at all possible. Alot of good solar options out there if electricity is not available. Also can be eligible for NRCS cost-share and possibly tax credit for using alternative energy. Also, I know a fair amount of folks who show 30-50 lbs. per head gain per animal with the fresh water. Just a suggestion. Whenever you start doing alot of earthwork on those dams...it adds up quickly. Also, it is getting much more difficult to find contractors to do so

Thanks for the input so far.  Actually in our situation even though I refer to it as a "stock" dam it is no longer used in this way.  We actually fenced it off from the cattle a couple of years ago due to the drought and had a well drilled that provides the water for the cattle.  Trying to maintain the dam more for wildlife/conservation reasons now.  I am definitely fearing what the potential cost of doing a good repair is going to be.

Install a "glory hole" type device, or a concrete spillway.  I've noticed a lot of new G&F funded dams use a glory hole.

http://fogonazos.blogspot.com/2007/02/largest-drain-hole-ever.html
In case you don't know what a glory hole looks like, here's a link.  Take it from me, you don't want to have your kid google "glory hole".  It seems the porn industry has also claimed the term as well.

corfit7,

Need more details as to what is wrong with the dam. Is the water going through an open-channel spillway or just overtopping the embankment? How bad is the erosion? Need more info.

TUFFdog

The spillway we have in place seems to be working fine but we do not know if it was clogged or not when the inflow of water started.  From what we can tell the water did go over the actual embankment and broke off some large chunks of the embankment on the downstream side of the embankment.  A hole developed in the area where the embankment was damaged and the water is raging through it.  The hole appears to be a couple feet below the top of the dike but the water is flowing fast down the backside of the dike and causing even more erosion.  It is hard to tell how much damage we are taking on.  The weather conditions didn't really allow us to investigate as well as we would have liked.  We are anticipating the worst here.  Might need to just rebuild the whole dike.  Sucks.

"Glory Holes" have a theoretical advantage to a plain spillway.  I put them in all my dams when they were built, but ended up taking two of them out.  Plugging them with conctete, actually!   They work well for flowing water, but I converted my main ones to a conventional spillway system using a combination of concrete and huge metal pipes. 
For the average stock pond where you won't drive over it as a road too much, I'd put in a conventional spillway and line it with concrete and and rock the heck out of it on the downstream side.   Much cheaper and less hassle for a small stock pond than a glory hole system, which work well on larger bodies of water or flowing water. 

Open-channel or Drop-Inlet Spillway?

Tuffdog, you got me on that one.  Never heard those terms before.  Not sure which one best describes our spillway.