Pond Boss Forums POND CONSTRUCTION Renovating a Pond or Lake? Renovating a leaky pond

I have been studying this site for a while and I have been impressed with the wealth of information here. What’s even better is that you sound like a good bunch of folks. So, I am going to introduce you to my pond project. My wife and I returned to Chapel Hill, NC last year and bought a house and land just south of town. The land had a ¾ acre pond on it and I recognized that it was going to be a project. My first question was “who in the world thought you could put a pond on this gritty looking soil and expect it to hold water”
[img]http://picasaweb.google.com/chip.chescheir/Pond#5389234222070969266[/img]

Other than the soil, the site is quite nice. It has a stable forested watershed about 15 times larger than the pond area. Since I am a watershed hydrologist, I had to install a stage recorder and rain gage to monitor the pond while we addressed other projects. So, here is the recorded stage in response to the rainfall for the last year.
[img]http://picasaweb.google.com/chip.chescheir/Pond#5389234212658952450[/img]

Yes, it leaks. It loses about .75 to .80 inches a day in the summer and about .4 inches a day in the winter.

[img]http://picasaweb.google.com/chip.chescheir/Pond#5389234218814896962[/img]
My neighbor said that he could have told me that before I put in the monitoring equipment. “But”, I tell him, “You could not have appreciated the classic behavior of the forested watershed. It’s so cool: hardly any response to summer rain events and greater response to winter events”. By this time his eyes have glazed over and he is thinking about the batch of beer he is making (a good hobby for a neighbor). Anyway, I would estimate the leakage rate at about .5 inches a day. Summer evaporation in the area is about .25 inches a day and during the winter and spring the inlet stream has continuous flow. The rate is pretty constant regardless of the pond level.

So what do I do about it? I believe that whole thing leaks, but it may leak more from the deeper areas near the dam. I do not see any big leaks in the dam. I have considered the options suggested by the Pond Boss group: bentonite, local clay, or a pond liner. I was sold on bentonite until I heard that another neighbor has some local clay. Then after I drained it and saw all of the muck in the bottom of it, I thought that the expense of removing the muck to make way for the clay or bentonite would make that option too pricey. Why not cover the muck and all with a liner? Ouch! That is expensive too.

I see the pros and cons of the options as:

Local clay
Pros – It is available.
Cons – It will probably take about 200 truckloads and I do not have access for a dump truck to the pond bottom, so the clay would need to be dumped in a staging area and moved to the pond.

Bentonite
Pros – It would take less volume
Cons – It is a long way to ship it from west Texas. About $1800 a load for the material and $2500 for shipping. I would likely need three loads. I will need to remove a lot of rocks before I can till it in.

Question about Clay and Bentonite – Would I need to remove the muck before I put in the material?

Liner
Pros – Seems most likely to work
Cons – Expensive material. I would need to move a lot of rocks. I do not think I would need to remove the muck (might be a good cushion)

Question about a liner – how much professional help will I need to install it?

What about having someone come in with a track hoe and remove the muck from the deepest area and sling it up on to the medium and shallow depth areas? Then fill the deepest area with the local clay and put the clay along the deeper parts of the dam face (maybe 30 loads worth of clay). Then I could try this DB-200 stuff over the slung muck on the rest of the pond. I could refill it and see if it holds. If it does not, I will drain it again and put in a liner. All of the prep work for the liner would already be done.

Do you all have any ideas?

Other info: Target stage would be just below the tree line. It would be up to 15 ft deep at this level. (The water level in the graph is not actual depth)

Other Photos:
[img]http://picasaweb.google.com/chip.chescheir/Pond#5389234224146483138[/img]
Before Draining

[img]http://picasaweb.google.com/chip.chescheir/Pond#5389234225492416754[/img]
During Draining

[img]http://picasaweb.google.com/chip.chescheir/Pond#5390040450740666514[/img]
Current state, Yuk!!

It looks like I need some help with getting my photos up and visible

Chip C
Welcome to the forum, You are going to love this place, and we are going to love you.--Any body who will put monitoring equipment up is a friend of ours. Do not let your neighbor get you down he does not understand you like we do.

First, Clay, bentonite, liner all start the same way the ground will need to be dry enough to drive a pick up on.

If you are going to work on the pond lets go the whole way.
Start by cleaningout the muck. You will have to find a place to store it and that is always a problem.

If you have any trees on your dam now is the time to remove them.
You can enlarge the pond or make it deeper.

After the muck is out then you can fix the leak.
It will look like a bomb hit until the job is completed but it will be worth it.

Make some plans as what you want a year from now.. Fishing--swimming-- a dock-- what you want around the pond.

Another option is adding water to keep the pond full with a well--check on that.

Not many do this but we do it down here in south texas. All the other stuff it high prices. We use salt lots of it, till it in with plow or tiller and once you put the water in salt expands and bada bing no leak and the salt doesnt hurt your fish in most cases it helps them out.

I was waiting 'till Otto chimed in. Considering Otto's experience, I think his advice (while the most costly option) is the only one that will yield 100% results with no worries if it is done right. You can try a different option, but you'll always have the thought "I wonder if this will work for me?" as the pond is filling up, and you won't have your wife asking why you have to spend money on the pond again when it should have been fixed the first time.

Not sure of your soil type, but for me it is a no brainer. Because of my soil type I have to go with a liner. The nice thing about a liner is no leak worries if installed properly. To me this would be worth the ~ 15 -20 k + cost for a 3/4 acre liner/installation. I would for sure listen to otto and remove all the muck first along with all of his other expert suggestions. If you have to truck in clay and then line the pond with it you would be surprised how close the expense would be compared to a liner, and even if you line it with clay it's not 100% guarantee like a liner. Just my $.02

Thanks for the good advice, Otto. I am dreaming of fishing and swimming and a dock would be nice. I am not afraid to put up some $$ to make this dream come true. I see that I will need to move and dry the muck before I do anything. Do I need to move it out of the pond? I would estimate that there is no muck in the shallowest 1/4 acre, about 3 inches of muck in the medium ¼ acre and 1 to 2 feet of muck in the deepest ¼ acre. Could I move the muck from the deepest area and stack it in the shallow area to dry. Maybe hold it with a silt fence and put it on drain tubes to promote drainage. I guess what I am really asking is: can I spread the dried muck back over the pond after it is dry. It seems to be pretty silty with a little organic content. I do not feel a need to make the pond deeper. I am really amazed that the muck does not do a better job of sealing the pond. I guess it is because it is not compacted.

Gallop, I see the advantage that the liner is a pretty sure bet. If I get out of this for under 25K I will be satisfied. I have several questions about a liner:

1) It must interfere with the natural interaction between the soil and the water. Does this create any problems.
2) In some literature, I see that it is required to put soil down over the liner. How is this done without damaging the liner
3) The prices I have seen for the liners are in the range of $.38 to $.42 per square foot. That would put the cost of the liner at $12 to 13 K if my pond was a perfect rectangle. I expect that I am really looking at $15 +. What is the typical cost for installation.
4) Do I need an underliner? Maybe that soft muck would work well or should it be put on top?
5) Do you or anyone else have preferences between EPDM and PPL-24? Are there other reasonable choices?
6) How far up do I bring the liner? Up to the target pool or to the flood pool. Will a flood create problems?

Thanks for your alls input.

I cannot see my photos and I assume that you cannot see them either. I have tried to fix this but have not had success. Would someone please direct me as to what I should do?

Thanks

ChipC:

I was able to view them by pasting the info. in the browser window. I have no experience posting pictures here using a hosting service other than photobucket. The only advice that I have is to read the archive thread about posting pictures, which probably won't be much help because I'm assuming you did that already.

how to post pics

Did it leak when it was drained down to the deeper area near the dam that you were talking about?

Montgomery, thanks for fixing the photos. Did you have to copy them to your web site?

I am pretty sure the pond leaked even when it was down in the deeper area.

Oh, I understand how to work the photos now

Hi ChipC. I'll leave the advice for the experts. A belated welcome to Pond Boss. That's for jumping in and posting. Hang on and you'll get more feedback.

No, problem I figured while I was looking at them I would give it a try. Reason I asked if it leaked when you had it siphoned, is maybe you could apply some bentonite or add clay in that area.

Maybe it would slow the leak to something you can live with?

Oh I just looked at the graph more closely, it all but dries up in the summer right?

The graph is a bit misleading in that the zero point is at the level that I installed the monitoring well. At the zero point the pond is about 7 feet deep. If you look at the fifth photo down (the one with the pond most full), the level shown there would be about zero on the plot. The water level in the pond is about a foot below the base of the trees when the graph reads 72 inches. Sorry for the confusion.

I have thought about just filling the bottom pool with clay. The soil is so bad everywhere that I think it would continue leak at an unacceptible rate. I will post some better photos of the soil later today.

Here are some photos of my soil. It's great if you are looking for good drainage

Porosity with a captial "P".

My goodness!!!

Judging from those reactions from a couple of lunkers, I need a Liner with a capital L. I talked to BTL and got initial quotes on a PPL-20 and PPL 24. There was a significant saving on the PPL-20 and the sales guy thought it would be good. Does anybody have ideas about this?

Hey, I am getting all sorts of questions answered by reading "ask the Boss" This is a great resource! Many thanks to the organizers and contributors

Chip, have you had core drills perfromed? There may be clay underneath that loam that you have. Try this link and go to your area and it may tell the type of soil you have.
http://gis.enr.state.nc.us/sid/bin/index.plx?client=zGeologic_Maps&site=9AM

Just a thought. You may have potential for a nice deep pond.