Pond Boss Forums POND CONSTRUCTION Building a dam new dam construction

I am gonna start building my pond in august.The dam will be 250 long & 7 ft. tall.I have some ?'s I need help w/.
1 What size of dozer should I get for pushing dirt approx. 100 ft. I will rent for 40 hrs.
2.Do I have to use a sheeps ft. to construct the keyway in the center of the dam & or all banks?
3.What size of overflow pipe is needed/I have 30 acres that flow over me from a valley?
4.Can I simply use a spillway instead of a overflow pipe?
5. How do i size an emergy. spillway if i use overflow pipe?
6.What is the best panfish to stock?
7.Should I stock w/ SMB orLMB?
8.What are other fish/hybrid bluegill etc.
If anyone has any info....please tell all

I am gonna start building my pond in august.The dam will be 250 long & 7 ft. tall.I have some ?'s I need help w/.

1 What size of dozer should I get for pushing dirt approx. 100 ft. I will rent for 40 hrs.
I'm not a dirt guy, but my feelings are bigger IS better. You can push more dirt with a larger machine, and you might find some suprises or "treasures" once you start pushing ground around.

2.Do I have to use a sheeps ft. to construct the keyway in the center of the dam & or all banks?
I would say yes. You won't be able to get enough PSI on the dirt to compact it properly without one. Also, don't try and pack more than 6" of dirt at one time (6" lifts). You won't get it properly compacted if you try to do it all at once.

3.What size of overflow pipe is needed/I have 30 acres that flow over me from a valley? I know that's a longshot here in Indiana, but try the NRCS in your county.

4.Can I simply use a spillway instead of a overflow pipe?
You can, but I wouldn't bet on it lasting for a long time. Water will erode the spillway, and eventually cut right thru the dam.

5. How do i size an emergy. spillway if i use overflow pipe?
See answer to question 3.

6.What is the best panfish to stock?
That depends on your goals for the pond, and how large the pond will be. Can you fill us in on what size the pond will be (surface area and depth), and what your goals are for the pond?

7.Should I stock w/ SMB orLMB?
See answer to question 6.

8.What are other fish/hybrid bluegill etc.
See answer to question 6.

If anyone has any info....please tell all

If you haven't done so yet, look at the upper left of the home page. Click on books, and order your library. The information in the books is invaluable. I have gone back thru mine quite a few times since building the pond.

It's good that you've found this place before you started digging. I didn't, and there are a number of things that I would have done differently had I known better!

Welcome to the forum!

Grant,

I admire your initiative and excitement, and I don't mean to burst your bubble of doing it yourself, but I would strongly recommend you get some professional advice on the dam design, and also with the construction. We've had 18 dams built on our property, and many years ago my grandpa was in that business. Thus I've been around dam building most of my life, and only now would feel confident in designing and building one myself. I've learned a lot sitting down with the NRCS engineers, and being on-site and helping out in various aspects of constructing the dams (such as installing the principal spillway tubes).

Bilding a dam requires much more than just a dozer (which is a very inefficient way to move dirt). You will need an tracked excavator to dig out the core trench, while a scraper or two haul good clay to the end of the trench, while the dozer pushes and packs the clay into the trench as it is opened. I'm assuming you will be in the same situation as I am in eastern South Dakota, where subsoil water will flow into the trench as it is dug.

If you are very lucky you might be able to excavate a "dry" core trench, and have scapers run through the entire trench after it is dug. But even then you will have to hope for a period without any rain, until you get the core filled back up to the normal elevation.

As esshup noted above, compaction of the clay fill is also critical, but as important is the quality of the clay. A simple test is to moisten the clay and then roll it between your palms. If it will form a long narrow ribbon without breaking, then it should be good clay. However some areas have dispersive clays that can be problematic. It's also very important that you make sure the core trench reaches into solid clay to form a good bottom seal.

Your principal spillway pipe size depends on what type of soil cover is in the uplands, and what your 25 or 50 year storm runoff is. As a rough guess based on our ponds, I'd assume you have 1.5 times more rainfall than we would, so perhaps a 2 ft diameter pipe would be sufficient. You also need to decide if the pipe will just slant through the dam, or if you will use an initial vertical drop structure that will allow a smaller horizontal pipe. Installing this pipe is a trick to make sure you have adequate compaction and a good antiseep collar. For the secondary spillway I would think 12-14 ft wide would be sufficient, but you will want to ensure that you can get the water around the pond and back down into the normal channel with a mild slope.

The principal spillway is obviously set at your water level, and then the secondary spillway would be 1 ft above the top elevation of your tube. The top of the dam should be 3 ft above the emergency spillway. Thus with a 2 ft pipe, the top of your dam should be 6 ft higher than your water level. If your dam height is only 8 ft, that would leave you with only 2 ft of water.

With snow cover and winterkill (or summerkill) issues, I would suggest you would want to have at least 10-15 ft of water in your pond. You might be able to get some of this by excavating out the muck, but it is generally cheaper to build the dam higher. In SD our dams need to be about 18 ft deep to prevent winterkills when we get snowy winters. You will also want to make sure that your water doesn't back up onto any neighbor's property, and of course, that there are no critical structures below it. I assume you will need to at least file a location notice or something like that. Larger dams holding more water generally require additional state permits. Your state's environmental department can help with that, but your first stop should be with a NRCS engineer, or a private engineer. If you need to pay for this service, it will be money well spent.

Yet another great post Bill, keep them coming!

how many cubic yrds. can a 140 hp. dozer move in 40 hrs.?

It depends on what time it left Chicago and what speed it was traveling! Sorry, Grant, I've got nothing when it comes to this category, but your question just hit me like one of those junior high math problems that I sucked at back then, too!

What kind of soil, what condition is the soil (wet/dry), how far does the soil have to move, and how many hours of seat time in a dozer has the operator had?

well that all depends. how far does it have to move it? is it rocky? is the soil tight or need to be ripped? etc. etc. the operators experience is also a huge factor. just for estimating dirt that i believe will push good on a 1500 cubic yard pond that i only had to back up 200' max i would estimate 90 yards a hour but that would include smoothing everything up which can be time consuming. my cat handbook says my 140 hp d6n will push 200 cy per hour 100' on level ground. that is very doable. but i can honestly say this i have spent over 50,000 hours of my life on a dozer and the first 2000 hours i was totally learning how. go to renovating a pond then to my new project a pond mother nature has taken over i made a post there with pictures of a pond and how long it took to build it.

the soil is clay & the pushes are 75-100 long

to push it and place it experienced operator 125 to 150 cy per hour. deduct 20% average operator,deduct 40% inexperienced operator per cat handbook and i think it sounds reasonable