Pond Effects on Water Table and Other Questions

[Woolhouse]

Hi,

I've got a 60 acre farm in upstate NY. The farm includes multiple springs (seven, according to the deed), and I'm pretty sure the area in question is on one of them. Not far from the house is an area we call "the swamp". It's an area of about an acre covered by cattails and other marsh vegetation. Though the ground is very wet year round, there is little standing water, just enough puddles to breed an unlimited supply of blackflies, deerflies and mosquitos.
The whole farm is a sort of bowl-shaped valley, with pastures on the sides of the bowl, woods around the rim and arable land at the bottom. The swampy area is the dead center bull's eye of the bowl.
I thought I'd dig this area out into a nice little pond. At least then I could throw some minnows in to eat the larva!
I dug a test hole of about 10 X 10. It filled to the brim in about 2 hours (during a relatively dry week). Water started seeping in less than 6 inches.
The mucky topsoil is about a foot deep. After that is a dense gray clay. I think it is kaolin with some silty stuff thrown in. Anyway, it's the color of cigar ashes and you can mold it like Play-Dough. I'm really not even sure how the water gets in through this stuff, as it seems pretty waterproof, but it does.
Anyway, the "test hole" is thriving, with several frogs and a snapping turtle already in residence. I'd like to excavate the whole thing and see what happens.
Some questions:

1) What happens to the water table in the surrounding area? It could stand some drying out, so I was hoping the pond would take up the water and give me some extra usable pasture.

2) I don't have a dozer or excavator and I am too cheap to rent one. I was planning to do this with my tractor backhoe. I figured I could dig a bunch of mini-ponds like my test hole, separated by a couple of feet . Yeah, they'll fill up. But then I could use a PTO driven trash pump (~200 gpm) to drain them, then scoop out the dirt between and combine them, also using the trash pump to vacuum up the goop at the botoom. Continue until I have one big pond. Seems sound in theory. I'll have to get down in the mud and shovel the "partitions" by hand, but hey - I spend my days up to my ankles in cow poo, so I think I can handle it. Is there any reason this won't work?

3) Could this pond "steal" the water from my house well? Since the house is spring fed, it's only a few feet deep. The swamp is about 200 yards from the house, but that area is dry. Is it possibly the same spring? I'd hate to do all that work only to find out I don't have water to my house anymore!

I appreciate any advice or thoughts on this project. Thanks.

 

[Mmathis]

Wow, a big welcome to you! That is some project!

 

[fishin4cars]

I did this last year at our place, we didn't have a bowl but we have a drain off from up the hill that flows into the pond that keeps it full of water. A small pond shouldn't really effect your water table or your well, If the water is seeping in already it would have been doing that for years and hasn't effected your well or water table so I seriously doubt it will make much difference for the pond either.
Best bet is dig as deep of a whole beside this area as possible and try and get the water to drain to this area, install some type of pump with a flavor valve so each time the hole fills with water it will empty it and shut off when it's pretty dry.
Using a tractor be careful, Mud is heavy, and it can be hard on your hydraulics. Also once your digging the pond it will start to get a bowl effect, This can throw the tractor off balance when the bucket is filled with mud. Don't do what I did!
Make sure you design some type of over flow. Even though you have a bowl there is going to be a point when heavy rains come in and you will want a top water level if possible or it may drown the plants along the edge. Which could be a good thing if you design a high over flow.
I would recommend trying to find someone in the area and get a estimate on how much it would cost to get it dug out with the proper equipment. I already wish I had made a stronger levee and moved my overflow to a different location. But for now I'm going to keep what I have. The last pic was taken about two weeks after we got it built before the overflow was installed, wouldn't have mattered much, it flooded anyway. First pic is the most recent pic however it looks different now as more plants have filled in.

 

[adavisus]

By digging the pond that will collect more run off and retain more water, raising the water table. The surrounding ground surface will be better drained and less swampy

 

[Jason]

Wow You are lucky to have so many spring vents near you! I had a similar sort of problem when building my pond here in Florida, I have a small pond But The woods behind my house are swampland and 1/2 a mile from me south is the Gulf of Mexico and 2 Miles North of me are about 10 major cold water springs owned by Nestle Bottle water Co. and Culligan Water Co. as I live above the largest aquifer in the world I could only dig my pond 2' deep as you hit water right at that depth. I lined bricks all along the sides and shelves of my pond to give a more sturdy ground before adding hundreds of pounds of rock and thousands of pounds of water inside the liner. We had a really bad rain here for about 5 days straight and My back yard was almost full of water and all i could think about was my pond getting pushed up by the water table and losing all my hard work, but thankfully that never happened even thought the water level was right with the top of my pond on the ground outside lol. ANYWAYS I think the reason My pond did not Get pushed up is because of all the rocks and granite inside the pond but I could be wrong, Maybe try that on a Much Much Much larger scale and it could keep the Liner down and build the sides up a little so the run off goes elsewhere.

 

[Jason]

Nvm just saw you were not using a liner :banghead3:

 

[Woolhouse]

MMathis - Thanks for the welcome! Truth be told, I've wanted a pond on my place (that wasn't engineered by @&%)*@ beavers!) for years, and I am very excited about it, My neighbors all tell me I'm nuts, and I need to hire to D8 to get it done, but hey...they dug the Panama canal with picks and shovels.

fishin4cars - I got a couple quotes for pro-diggers, and most of them came in at 5 figures. Heck, if I could afford that, I'd just buy myself a dozer and have at it. But, I am confident I can get 'er done. I've got three things going for me: 1) confident 2) hard working 3) not-very-bright. I am building the levee out of that clay subsoil. The stuff bakes in the sun until it's as strong as a concrete blockhouse. I was going to put a culvert pipe at about 2 feet over the normal water level, aimed at a natural run off ditch that discharges the area already. Do you think that will work?

adavisus - So the pond will dry out the swamp AND give me more well water? Wow, if I'd known that I'd have done it years ago.

Jason - Yeah, the spring heads are great, especially raising cattle. Three of the springs feed streams, one feeds the house well, one the barn well, one is "the swamp" and one is a mushy, ferny area in the woodlot. The only downside is the beavers. They keep damming the springs and making a holy mess of my pastures!
I figured a liner would just float away, given the speed that this bad boy pumps out water. The natural clay subsoil seems pretty impervious and my "test hole" is crystal clear as long as you don't mess with it (I can always find the turtle by the little cloud of gray mud at the bottom).

 

[fishin4cars]

LOL, You sound like me, problem is that's what's worrying me. I was sure I could do it, my buddy who is standing in front of the flipped tractor and I worked on this little Hole as I guess you would call it for two days straight trying to get it dug out during a dry spell before the tropical storm came in. As you can tell, I didn't think things through quite throughly enough, Sure didn't think it would be filled from flood a short time after digging it. One issue I really had to fight with was working with the big clumps of clay and trying to pack them down for the levee. I couldn't pack the dirt very well length wise on the levee, I had to keep driving and packing from inside the pond. Somewhere in that pile I didn't get a good packing and I still have a small leak during full capacity. Once the water level drops about 6-8" the leak stops until it's full again. If I would have gotten my hands on a dozer I would have been able to pack my levee a little better I'm sure.

When I rebuild it which I'm sure I will have to at some point I'm going to get someone to come in with a dozer and rework mine. It works for now and what I needed but I really know it could be better done with the right equipment. Since that time I have met a local neighbor that has a small dozer and he just happens to need some tractor work, so we have been working on a trade off, I have cut his field a couple of times and this fall I'm going to help him disk up his back lots, (6 acres) for food plots for his deer herd. In exchange he is going to give me a hand with his dozer when I go to rebuild. I understand what your saying on getting a pro to do it. I got quotes of $5,000-$8,000 to do mine as well. It's not even a 1/4 acre pond! But doing some checking around and watching craigslist I slowly found local resources that have been quite useful. Not saying the tractor won't work, as you can see, It will. Just make sure you be careful. It's not designed for that kind of work and being confident you can do it not being very bright can have it's disadvantages. AS YOU CAN TELL! LOL That one little goof up cost me a extra $500 to get someone over to help me roll my tractor over and help me move it to high ground so all the engine oil would settle back down in the oil pan before I started it back up and before the rains came in. I was seriously worried it was going to be under water if the rains came in before we got it back up out of the hole.

It was a fun project though and I don't regret doing it myself. I learned quite a bit during the build and there will be some changes when I do get around to rebuilding it in the next couple of years. for now it is stocked with channel catfish and they are growing like weeds. By the end of this summer I should have about 200# of catfish ready for Harvest. May do raise another batch of fingerlings next year before rebuilding mine. Good luck and yes BTW, I do think the culvert idea will work just fine for you.

 

[HARO]

Woolhouse; do you not have access to an agricultural agent or county extension office or whatever they call them in your area? Around here farmers can get free advice on pond builds, as well as financial help in many instances. Might be worth a try!
John