Pond Boss Forums POND CONSTRUCTION Soil questions Soil Type Question

I am in the early stages of planning a pond. I have had our NRCS rep to the site and he said it looked like a good spot but thats about all the help I'm going to get from them. They have been told that unless the pond is going to be used for livestock they cannot help. The soil scientist cannot do soil samples either as he has been told the same thing. Has anyone else ran into this problem?

Anyhow to my question. The pond site is a natural valley that has a seasonal creek running thru it. There will have to be some excavation to get the types of slopes I want but not enough I feel to build the dam. I've estimated the surface area using a CAD program to be around 1/2 an acre. I have an area to borrow fill from above a driveway that was put in 20 years ago. 12' of the bank was cut away for the driveway. The dirt apears to be uniform the entire height of the cut. As I started digging around to look at the soil I started to get worried. It contains alot of rocks that at first looked like shale. After messing around some more I noticed that the "rocks" could be broken easily and could actually be crushed to a fine powder in my fingers. Also when digging the "rocks" can be sheared with the shovel easily. The rocks are flat usually around 1/4" thick. I decided to do the bucket test I've read about here. I drilled several holes in the bottom and low on the side of a 5 gal bucket. I lined the bottom with 3-4" of gravel and then put around 8" of soil over that. It was packed with a spud bar. It packed very well. It was then filled to the top with water. Its been three days now and the water level has only gone down less than an 1/8 of an inch with no water coming out the bottom. I also did the jar test but it was pretty inconclusive do to the rocks. The area is said to contain a lot of clay according to the local farmers. Can any one comment on the type of soil this is and whether it would be good core material for the dam? By the way, I'm from the northern panhandle of WV.

SteveG, I would find a reputable local earthmover who knows local soils, bring him out to look. I suspect once you move and process those soils, you will have good material to work with. I have seen many sites with crackly, rocky-looking crusty material that makes fine dam building dirt. But, an experienced earthmover or a nearby engineering firm can help you locate a soils lab which can tell you the 'plasticity index' of your soils. The next issue of Pond Boss, which comes out at the end of Oct, has two great stories which help answer your question. But, in the meantime, you should get some help. Even though the NRCS won't help, they should know someone who can help.

I have a long gully about 700 feet long and 100 or more feet wide. The whole 10 acres is a sandy red clay mix. The sides of the gully are about ten feet high. The dam will be about 120 feet long between the two sides of the gully. Do you think the sandy part of the soil will cause problems in sealing a dam or with it being mixed in the red clay help seal a dam?

Most earthmovers will tell you a 30% clay mix with other soils is compactible. I would contact the NRCS to help with a soils analysis, so you will know. Ultimately, some test holes will show what you really have. With someone interpreting what the soils mean, you will be onto good advice.

I can walk anywhere on my ten acres, brush the top soil aside and pick up a hand full of soil. roll it into a ball the size of a baseball, let it set for an hour or so and it will be as hard as a rock. In the gulley, you don't have to brush the top soil aside to do this.

Steve,
Regarding NRCS assistance (or lack thereof), you will find varying opinions within this forum of their strengths and participation in a pond project. Your NRCS experience is not unusual. I have had the distinct pleasure of spending short term quality time with a few different NRCS offices in my region that rose to the occassion big time. This occurred while I was searching for the right pond property to develop. Sometimes, tho, some offices are cordial and want to be helpful but are restricted because of available personnel. It also seems in these cases that there is a "decree from above" about what type projects they are going to promote...or not. They do have an obligation to assist in securing soils maps and technical data regarding the same (be careful, tho, because soils maps are "scatter-gun accurate" and only provide a glimpse). In your case, perhaps the most help that they can provide is a list of local experts as Mr Lusk has noted above.

Steve,

I have done the soils investigations on hundreds of sites over the years and have four ponds built in valleys on my farm. Two of which were built by others and leak. Soils maps can be very deceptive since they only show surficial soils, typically 18" deep. Valleys are dangerous because often there are alluvial deposits inclding sand and gravels in valleys.
You or are the right track with your "quick and dirty" permability test. Dig a couple of test pits in front of and behind where the dam will go. Look for sands and gravels. An experienced contractor can guide you in the right direction.

ditto a couple of good points by Jas
I was told by more than one source that the soils maps were samples extracted in 1960's or '70's and they never went deeper than 60"...truth be known? anybody?
last August, my contractor took 2 days to beat thru the woods to clear a drive to my pondsite and boy was I nervous when he started digging with the excavator for soil samples. The very first hole...4..6..8 buckets...all black and crumbly. 9 buckets, same thing, I think I'm gonna be sick. 10th bucket, he sets to the other side of the hole, gets out and grabs a handful. He rolls it into a ball in his fist and starts working a flat ribbon thru his thumb and forefinger...it gets about 3" long while I'm staring like a deer in the headlites. He looks up at my white face and says "this is good stuff". I collapsed and fell into the hole! (just kidding...I only collapsed).

We all know how you felt Brettski!

My grandfather worked for the ASC (NRCS replaced it) in the 60's taking soil samples in Johnson and Cass counties in MO. Samples were only taken down to 36" deep. I still have the probe he used to take them.

h2O...
v interesting. Thanks for the feedback. As a side-bar, can you post a pic of the probe and/or describe it?

It is hollow pipe with a T handle and a slot down the side to ease the removal of the core samples.

Brettski,

If you search on Ben Meadows or Forestry-Suppliers, they should have a picture of a soil probe in their catalogs.

I was kinda thinkin' that it might be one of those "Antiques Roadshow" relics. Apparently it's another timeless design...like a mousetrap.

You could build a very nice pond with what some of those Antique Road Show relics bring!

Using a tube sampler might be tough with coarse fragments present.

Sounds like you have shale or mudstone. If it breaks that easily, you might be able to pulverize it with a sheeps foot or by tracking it in with a dozer or front end loader. You would have to apply thin lifts, maybe 6" or so, and crush/compact it evenly before building it up higher.

I'd be more concerned with what you are tying it into in the walls of the valley. Also, if the shale is dark, it could be a source of sulfuric acid. Do plants have any trouble growing on it? Do you see any yellowish spots?