My first pond was a clay bottom scraped out low spot. Dried up for a week or two in summer.

Check with local federal government, may Ag Dept. They may have some info for your area, may send someone for free to test soil conditions, maybe even kick in some grant money if you keep the pond as a benefit to everyone, like a wetland.

You couldn't really keep a clay pond filled from a hose. Unless you're talking 24/7 full on. If you had access to a large water supply and big pump than sure.

How deep you want to go really drives the design. If you scrap the topsoil off for a shallow deal it won't look good for at least a few years. Takes awhile for plants to grow in clay. I had a couple of other scraps and all acted differently even though they were just a couple hundred yards apart. One always had muddy, milky, water from the clay. One never did anything too interesting. The biggest was a real pond.

Since you don't want fish you can scrap off the topsoil, then scrap out some clay, maybe 12", so now you're down 18, 24 or whatever inches. Push the topsoil back over the entire deal. Then plant marginals around and inside. Search for "vernal pools" to see how these things work.

Many pond plants, called marginals, will say something like , depth 6". But generally this is the maximum depth. Almost all marginals do better above the water line but in wet soil.

Based on my experience I wouldn't go in between. I'd either go with a real year round pond or a vernal pool.

You can search for more info, too. (Love the internet!!)

Search for Dewponds, Million ponds, Sodium Bentonite, puddling, clay lined ponds and clay lined canals as a start, Vernal ponds, too, of course(I forgot about that one). The clarity of the water will depend on how well the clay is compressed and the turbidity of the water. You might want to check out bog filtration, too since you want to utilize runoff.

You need to have a thick layer of clay that is free of intrusions such as roots, rocks and strata of other soil types. To retain water for a good length of time the clay needs to be compressed or puddled. The success of a clay lined pond depends on the proper material and puddling for the most part so you need to do a peculation or perc test to start so you know what is needed.

The DNR, in some areas may be able to give you some info. English Dewponds go back centuries and the British have been encouraging a resurgence for some time so their info is very good.

Sodium Bentonite is the clay commonly used to line most farm ponds and runoff retention ponds.

The success of a clay lined pond depends on the proper material and puddling for the most part.

To avoid mosquitoes you could check out solar fountains although they are not very efficient.

My ponds did get water from the water table. In spring the water level was basically above the soil line. Meaning lower areas would have standing water. Our water table dropped during the summer, and going by the level in our wells, would be about 20 feet below the ground. But the water in the pond was slow to soak through the clay, plus we got some rain. So the drop in the pond lagged behind the water table drop.

I would guess it's pretty rare to have a better draining layer beneath a clay layer. Otherwise I'd assume the fine clay would have washed into the pores below. In my limited experience clay was just above bed rock but could be very deep.

This thread reminded me of my old ponds, 40 years ago. So I went onto Google Earth to see if they were still there and they are. But now with big trees around them. One of scraped pond was to keep a spot from flooding and nature took it back to the way it was originally. It would be cool to go back there someday.

Thank you, guys, for your inputs! Lots of reading for me in the next few weeks. At least, now I know what to search for.

No fish ='s skeeters

Clay can certainly wash down into pores in soil below the clay strata but that doesn't remove the original soil so you would wind up with a mixture that would not necessarily have good water retention. The top layer of clay would be reduced to a thinner layer.

Changes of the ground can take centuries to happen naturally or it can happen very quickly as in a flood. Sometimes it doesn't happen at all or takes a millennium. Some strata can be very thin or oddly shaped or very thick. The ground is a history of the land.

Google "SRAC publication 105". It is a wealth of info on sealing leaky earthen ponds.
Several years ago I was raising fish in concrete raceways at a farm and decided to see if I could come up with a cheap way to seal an earthen pond. This was in AZ desert where material is mostly granular with very little clay. Having access to heavy equipment and manure I figured I would only lose my own time if it didn't work. I dug a 60' diameter pond 6' deep with sloped sides and filled it with water. At the end of 7 days the pond was dry. I dumped horse and cow manure (mostly horse) in dry pond and used an excavator with a sheep's foot roller to roll in manure. The roller did add some compaction to pond walls and bottom but the most important thing it did was it acted as a roto-tiller and mixed existing soil with manure to a depth of about 6". I filled pond with water and it held water as well as any plastic lined pond. It held water for the 6 years we used it and never required any maintenance during that time. Pond cleared within 2 months.
That method and more is in SRAC publication 105.

My son dug a pond last fall for me with a mini and shaped and compacted it really well. This is a pond that catches the rain run off. The the rain came and it worked and held water all winter. Now with spring the rain is here and it's still holding to the top. The run off goes into a dry creek that is a natural indention that we filled with beach stone. The pond is 20'x50' x 3.5 deep x 4.5 deep a peanut shape, on the deep in we are putting in a waterfall. We know it will hold the water and would like to use it as a swimming area or just float in it. The water is muddy looking and would like to know how we can help it look clearer. We do not have a liner and can't afford to put one in plus we would like to try to make it look as natural as possible. Please keep in mind that it does freeze in my area and we now know it freezes to the bottom of the pond. On the high sides of the pond how could we make sure that the clay won't keep clouding up the water as well as the bottom. I know this may seem like silly questions for some but we are learning and like any information that would be helpful. Thank you

It depends on what you want to use your pond for. If you just want marginal plants (cattails, etc.), you can have a pond that disappears and reappears with the rains. If you want fish or water lilies, you're going to need a liner and a hose to re-fill it. For fish, you're also going to need a pump and a filter. But if you just want marginal plants, you don't even need to dig a pond - you could plant them in the wet soil - which is already technically a bog. You could also experiment with both - dig a pond in half of the area and leave the other half of the area as a bog. Plant marginal plants in both and see which one works better.

To 12amilou - to clear up muddy water, if you're not willing to line your pond to prevent mud from leaching into the water, you'd have to install some sort of circulating (pumping) and filtering system. If you're looking for a summer swimming hole with clear water, that may be your only hope. But once sunlight penetrates clear water in the warm spring months, algae will be able to grow, which is why swimming pools use chlorine. Also, if you have leaves falling into it, that's going to create gunk that will need to be removed somehow if you want nice clear water. Or just swim in muddy water. Lots of people do it.

Our pond is dirt based - no liner. It was a former cellar under a small building but kept filling with water. The previous owner filled it up with rocks. We tore down the building, rearranged the rocks and let Mother nature take over. The pond filled with water. Our gutter water runs into the pond to help keep it full. We have an overflow running under our driveway and down a hill to keep the pond from overflowing. Fish and one now large water lily are doing well. A filtration system was added 5 years after the original set up. Muck is a problem so a few years ago we removed the fish and sucked out all that we could. Instead of using small rocks again, we replaced them with various sizes of field stone. We have 30+ fish and they seem to thrive. We never feed them. Our situation is unique. This pond somehow links underneath our patio as the fish winter under our patio. They swim through the rocks and re-emerge in the Spring. We have no idea what is under our patio. . how much water is held. . how deep. .but we know when the pond gets low the fish disappear. I do add tap water during the summer months as the pond does evaporate rather quickly. It's not likely the chlorine will hurt the fish as I add it in gradually over a few days. Sometimes I put dechlor in but usually I am careful not to add too much. Our tap water has never hurt the fish that are in there. In fact, as the water is added, the fish swim underneath - possibly enjoying the cooling hose water. This pond is approximately 10' x 10' and 2' deep.