I am starting to dig a new one acre pond. We dug four test holes. In two of the holes we hit a thin layer of sand followed by clay with some gravel mixed in. After we dug the hole it immediately started to fill up with ground water. For two of the holes we dug we hit about 6-7 feet of sand that was so saturated in water that it was basically muck. It was very difficult to dig with the mini ex. I figure that if it is a water table pond that I do not need to worry about it leaking I just have to deal with water table fluctuations. I have use on site for all the fill except for the sandy muck. My plan would be to dig the pond deeper than I otherwise would and fill any sandy muck back into the pond. Any guesses whether that muck, once the pond is full, would settle into a simple sandy bottom or would It stay muck on the bottom of the pond? Thanks.

Welcome Matt,

FWIW My pond is very similar to yours and built in similar soil conditions. My advice is do not put anything back into the pond. You will need all the depth you can get in a water table pond. I piled the "sandy muck" up on the side of the pond and let it dry out. I was amazed how quickly the water drained out of it. Once most the water drained out, it was much easier to handle and I just mixed it in with the rest of the fill.

Again Welcome,

Bill D.

I am sure one of the pros will be along to offer some good advice for ya!

Welcome aboard you will love this place.

Bill is right you will need all the depth you can get. Are there other ponds in your are? How well do stay full?

Matt,
Welcome to Pond Boss...tons of good helpful folks here. Post some pics of your project when you can. Good luck!

Here are some pictures of one of the non-sandy test holes. The closest pond is exactly one mile away and is full all year. Is there any way to figure out the fluctuation range other than leaving the test hole open for a year and observing?

If possible ask the owner of the pond a mile away if there conditions are same as yours--- a mile is a long way for the dirt to be exactly the same but that is a start.
I do not know of any way to check the fluctuation of the ground water, except to like you say dig a hole and leave it open.

What part of the state are you located in Matt? I am guessing up north by that dark dirt. I guess the one benefit to all the clay in my part of the state is it is easy to make a pond around here.

I am in Grundy County. So you would be right about the northern part of the state.

Matt:

I have a groundwater pond, and at times of the year I can hit water at 18".

But, my pond typically will fluctuate between 4' to 6' in depth, and currently it is sitting close to 5' low.......

I dug mine to 21' deep and don't regret it one bit. I've gone thru a winter with 12' of water in it........

Some ground water ponds stay full year round, most do not.
depth is the key, and you knowing what you are getting before you get done,