Pond Boss Forums POND CONSTRUCTION Soil questions To build a pond or not?

The Soil Conservation guy says there is nearly 20 Acres of watershed coming into my proposed pond site. As you can see from the attached images, much of the watershed area is wooded or lawn.


I have shown in the second image a pond with approximately .75 surface acres. The concern is about silt and leaves. The soil consrvation recommends nothing less than 1 surface acre with this much watershed.



I certainly don't have the experience to "over rule" his recommendation. I am hoping that some of you folks do.

Thanks in advance.

Dan

With the thick trees in the watershed, you should not have an issue with siltation, unless there's a lot of construction going on in the watershed. Don't really see how leaves would be a problem though.

The recommendation he gave you is very non-specific. The amount of water you'll get off a 20 acre watershed will vary greatly depending on several different variables. Those variables include average watershed slope, vegetation type, vegetation condition, soil type (sand =percolation, while clay = more runoff), and of course the intensity of the rainfall event. FYI the trees will help you by slowing the water as it comes down the watershed, moreso than open pasture.

I think you will be fine with the 0.75 acre pond. Just make sure you have a wide enough spillway (enough to handle a big storm) and you compact the dam well during construction. Recommend packing in 9" layered lifts as a minimum. If necessary, a sheeps-foot roller helps compaction if the soil has a high clay content.

Bigger is always better!

If you do anticipate a lot of silt and leaves you could always build a settling pond in the main drainage-way.

One thing you need to be cautious of is both fertilizer and insecticides running off the lawns.

Thanks for all the words of advice. I have laid out the approximate area of the pond and the future building location. I've been getting quotes the have a huge range of cost. Some as high as $40,000 for the clearing, gravel drive, and pond excavation. It starting to look like this project may be cost prohibitive. If anyone has experience with a contractor in the Cincinnati area that may be interested in looking at the job please let me know.

Thanks, Dan

Skip the gravel drive, save for another time. If the trees are of any value you can hire a logger to come in and pay YOU to harvest the lumber. You can then probably clean the rest yourself or find a landscaping crew.

That may take a chunk out of the cost, but nobody said ponds are cheap. $40K is a lot for a 1ac pond IMHO, should be in the ~20K area unless you are moving soil off-site or a distance that needs a dumptruck. I basing that on my experience of a simple 0.6acre pond being <10K without needing soil moved with a dump.

Depends on how many trees need to be cleared, height & length of the dam, material type for intake pipe, valve, etc., and how far the dirt needs to be moved from to form the dam, and how deep they need to go to put the key into the dam, ... a lot of variables so its hard to compare pond pricing.