Pond Boss Forums POND CONSTRUCTION Building a dam Rocks in dam construction

They just started building my 1 1/2 acre pond on my farm. Are rocks acceptable in the dam? If so what size are too big? I haven't asked the contractor yet about them. I'm concerned about leaks. Thanks for the help.

I'm sure the experts will jump in here shortly. I'll let you know my results. We found a lot of rock in the soil where we built our pond. The dozen operator stopped taking dirt from a couple of areas because it was just too rocky. One of the three guys working on the pond told me if it was his pond, he would stop construction right then, because we were in so much rock. I was already three quarters of the way through, so we went for it.
Indeed, I do have a small leak. (I lose between a 1/4" and 1/3" per day. Doesn't sound too bad until you go through a six month draught, and the pond is 4' below full.
We took every other precaution that we could, including bringing in a sheeps-foot roller to compact the soil as much as possible. We fluctuate a bit on water depth, but it's 15' deep at full, so I don't worry too much about the fish.
Do I wish it didn't leak? Yep.. If I had a do over, would I build it anyway? Absolutely! We love it. Swim in it, and are catching lots of fish with the grandkids. I just have to block out the 2' of exposed bank right now due to the low rainfall totals and leak. A buddy just put in a swimming pool. He spent a lot more than our 1 ac pond cost us. I wouldn't trade for anything. Try to get as much help from experts as possible. Dig test holes, etc.. Good luck! I hope it works for you.

SetterGuy, my soil is almost all clay. The rock came from an area away from the pond where they dug a hole to burn the brush. They put the dirt from that hole where the dam will be. One section had crushed stone in it.

Did they put crushed rock in the dam core?

Not sure how far along your project is but here is something to keep in mind. The dam consists of different parts, the sloped sides and the core. The first part of construction of my pond was pushing all the top soil and crap toward the dam. This formed the downstream slope of the dam and really doesn't matter whats in it. Now you dig down in front of the pile of crap until you hit solid clay. This is like the "key way" that the core of the dam is set into. The core is then carefully placed and compacted in from of the pile of crap. The core SHOULD NOT contain any significant quantity of rocks.

They also sometimes build up the dam out of whatever soil is available and then go back and excavate a trench through the middle and then build the core up inside the trench.

Here is a video blog of the construction of my pond from a guy who really knows his stuff.

http://www.youtube.com/watch?v=CablrsO4cto
http://www.youtube.com/watch?v=-AcgdmZpSUM
http://www.youtube.com/watch?v=LmnAAs5qH9w
http://www.youtube.com/watch?v=XoNZJsRnWMk
http://www.youtube.com/watch?v=9mqCRiazRyY
http://www.youtube.com/watch?v=u-EHoVGHiwE

Hope you fared ok in the storm! Glad that you have power.

I think I'm just nervous about the whole project. A big investment. They spent the first day clearing and on day two they dug a hole to burn brush in. They just dumped 5 or 6 dump truck loads around where the dam is going to be. The company has an excellent reputation on pond building. We just had a lot of rain here.

There should be as little rock as possible in the dam core and the water side of the dam. The back slope doesn't matter as much. Front slope and core should be compacted clay-as uncontaminated as possible. If there are a lot of rocks in the core that almost guarantees leaks.

We have a lot of rock in our dam, but there is also enough clay that it worked out just fine (apart from lack of compaction). Some of the rocks are quite large, 800 pounders and up.

As long as there is enough clay to fill the gaps between rocks like a concrete wall, you should be fine. The problem is if there is not enough clay to fill the gaps, or things are not compacted with the rocks in mind.

Another option is to make sure the larger rocks are set aside, you can then use them later in the landscaping, fish structure, and sitting/fishing platforms.

Well they worked all day on the dam. The dirt with the rocks was pushed to the side to use to fill in the burn pile hole. They dug the core filled with all clay. The soil on my farm is all clay so finding enough clay for the dam is no problem. They hope to get dam done by Friday. Then we'll start working on the shape. Its getting exciting to see my dream come true.