Pond Boss Forums INTRO Questions & Observations Building a Swimming Pond

Hello All:

I am getting close to finishing a pond on my property. When it is finished, it should be somewhere between 1/4 and 1/3 acre in size, and 15-20 feet deep. I have been trying to incorporate much of the advice I have read on Pond Boss, and have come to the realization that what may be recommended for a fish pond may not be ideal for a pond that has a primary purpose for swimming.

So I was wondering what advice you might have for a pond that will be for swimming. What should I do differently than for a pond that would be used to raise fish?

For example, here is a tidbit of advice I received from a forum member regarding aeration:

"Lifting in two areas effect all of your gallons and lifts slower at each location. A central station has more turbulence and can push water more aggressively to the shoreline perhaps pulling out soil that goes into suspension. Two stations will even out your temps more and the warmer the bottom the more aerobic bacteria. If your goal was to just keep fish alive any central air station would work. For your stated goal I would use the smaller piston compressor and lift in two areas."

I am just wondering if there are any other aspects of good pond construction that would vary between goals of fish and goals of swimming.

Thank you very much.

Backstroke

I would consider adding dye to help keep vegetation under control.

Thanks sprkplug. I will start reading up on that. At this point, my primary concern is the proper construction, since I do not want to make the wrong choices for things that will be difficult to change later.

Backstroke

If you are going to have a dock with posts into the ground, get them in before it fills up.

And if its still possible, make sure the pond is compacted the proper way.

Are you having a beach area that needs completing before filling.

Thanks, fish. I was advised against compacting by our local NRCS person, who came out to view the site. He said compacting would make sense in other parts of the country. But here in NH, and at my site specifically, there is so much ground water percolating up to the surface that you don't want to retard it by compacting. It is filling pretty quickly without rain! I feel very lucky.

Instead of a dock, we are leaving some huge boulders at the proposed waterline.

We are definitely planning for a beach, and will select the location as the dig gets closer to completion. There will be sand, for sure. Any other advice?

Thanks again.

Backstroke

Strongly consider a dock. It's not always pleasant to wade out through muck before jumping in.

Your goal for a swimming pond is to keep as many nutrients out of the pond as possible. That means these things if you can:

When the pond is built, don't line the bowl with any topsoil. Stick with subsoil or clay.
Make sure trees are nowhere near the pond as to not fill it with leaves. If leaves get in, get them back out if possible.
Do not fertilize near the pond. Make sure no runoff can enter the pond which may contain fertilizers or sources of nutrients (or pesticides for that matter). This may mean diverting water away if possible.
Don't plan on feeding fish, though you will definitely want some in the pond to control the bugs and snails. (Yellow perch, fathead minnows)

I'm not certain about aeration. Having that will keep the pond a lot colder near the surface delaying the start of the swimming season. Especially in NH. Its primary purpose in your case would be to keep organics from accumulating on the bottom. However it has drawbacks of high cost, keeps "stuff" suspended in the water column reducing clarity, and IMHO annoying to swim with.

Pond dye in a swimming pond will be effective at preventing vegetation on the bottom, but remember that it does not reduce nutrient load. You have to stay on top of dye since if you slip for a while, those nutrients will be put to use very quickly and you could have an algae issue to contend with once it starts. Instead you can have the option of planting desirable water plants to capture the nutrients before they are converted to less desirable gunk, such as water lilies and so on. Also just a couple grass carp can keep the nutrients trapped in the fish rather than the water. Just don't over do the GC, you want a little vegetation to help with clarity.

FYI there are some great threads on beaches here, I would suggest taking a look into it as it is much easier to accomplish before a fill.

Thanks, liquid. I just tried doing a couple of searches on beaches, and had no luck. Just "beaches" gives the message that I need to search for more terms. Additn "construction" did not help. If you can post some links to the threads you remember, it would be greatly appreciated. Thank you.

Backstroke

If you are not compacting the soil, and using the groundwater to fill the pond be prepared for the pond to have large swings in pond depth due to the swings in groundwater. I have a GW pond, and will see swings in water levels up to 6 feet. So, if you plan on walking into the water from shore, the bank will have to be tapered for a long distance to make walking (and not slipping) easy. Think of 3:1 max. slope which means at least 18' of pond bottom that may or may not be out of the water.

Also, that means a floating dock and not a fixed dock.

You can certainly add an aerator and just keep it turned off until the water has warmed considerably.

If you anticipate large swings in pond volume due to ground water, you could also build a concrete pad/steps along the 3:1 grade to make entry and exit more pleasant.

Ditto fish n chips & Bocomo!!! Backstroke, you wouldn't believe how many people (especially kids) would use the dock. Nobody likes that mud (muck) between their toes. Plus you could sit out on the dock enjoying some cool beverages while fishing or sunbathing.

Try pond beaches on your search.

Beach Link

This might get you started.....

If you have a lot of flow through in this ground fed pond and you are not feeding fish you might not have an algae problem. You also might have a hard time using dye if there is a lot of flow through. What does the water look like so far? I built my 1/3- 1/2 ac pond in low spot and it is fed by ground water. The farmer used to feed cattle there so the ground was very rich in nutrients. I had a bad duck weed problem when it was first dug but seems to be settling down. I also feed my fish so that doesn't help.

Aerate your pond during the day and or run a waterfall to warm your pond to give you more use on each end of summer.
I left an area (shelf) 1-3 feet deep to grow cattail s and other weeds to help tie up nutrients.

I certainly would listen intensely to advice given by local knowledgeable people and organizations. With having said that, if the ground water percolates so well in this area it would seem that as you dug the pond it would fill with water as its dug. Has that been the case?

FNC, mine filled with GW as we were digging and I had to run a 16,000 gph pump for at least 12 hrs before we dug every day. It's not a matter of water going into the pond quickly, it'a a matter of where will it stop once it gets towards the surface? In my pond, 6' water level fluctuation means going from over an acre in size to less than 3/4 acre in size. If I had only dug my pond to 12' deep, I'd be in trouble every winter due to shallow water conditions.

My biggest problem with the water level fluctuating is during the late Fall/winter the forage fish are swimming around in a bathtub without cover to escape predation, so I'm constantly battling a low forage proposition in my pond. Also, the aestics of the pond are somewhat lacking when the water drops, as I'm looking at 12' to over 20' of muddy exposed shoreline, and any cover that I placed in the pond in the shallow areas are sticking out like a sore thumb.

Esshup, I fully agree with what you are saying. I have a very similar situation. I had to pump with a 4" line every day. For me, too early to tell how much it will fluctuate over the years, but it has been fluctuating some.

My question to Backstroke was kind of vague and short. My thinking is that if water isn't coming in now, then why not since the ground is so full of percolated water. And then if it is coming in, at what level is it stopping, because that may be the best it ever gets, or could fluctuate up and down tremendously. I don't want to say that the NRCS person is wrong, but if it was me I would do some outside homework to learn more about the situation to verify/deny. Even if no water is coming in now, will that mean when it does rain will the soil type just let it all drain out,... after all the area percolates!

FnC, I agree completely! If I had my preferences, I'd prefer a pond that was sealed as much as possible after dealing with this groundwater pond. I thought by digging it down to 22' deep when we renovated it, I would solve my low water during the winter issues. I did, but didn't realize how bad the pond looks when the water level drops a few feet in the Fall, or stays that low for the whole year due to low rainfall/GW levels.

That's one of the reasons why I'm looking into dropping a well just to keep the pond full. Right now, my 25 gpm well won't keep the pond full even if it's running 24/7.

Good Morning Guys:

Thank you for all of your helpful comments, and especially fish for the beach link. VERY helpful.

To answer your questions, I already have quite a bit of water pooling up. This is 90% ground water. You can see how clear it is in some of the pics, where it is pooling up in shallow depressions:

http://i885.photobucket.com/albums/ac52/NHFamah/th_P1030259.jpg

http://i885.photobucket.com/albums/ac52/NHFamah/th_P1030261.jpg

The area beyond the large boulder on the left is where we are planning to put the spillway, because it is natural grade. The initial thoughts were to put the beach on the opposite side of the boulder, toward the camera.

http://i885.photobucket.com/albums/ac52/NHFamah/th_P1030262.jpg

That area near the front that is not excavated very deep is a ledge shelf. Beyond it, they were able to be quite a bit deeper.

Since the water level won't be very high as the ledge shelf runs into the shore, they build a retaining wall that I can landscape:

http://i885.photobucket.com/albums/ac52/NHFamah/th_P1030263.jpg

This is also the spot where most of the surface water will enter the pond. They made a spot for a little waterfall, and some rocks further upstream to catch some the debris:

http://i885.photobucket.com/albums/ac52/NHFamah/th_P1030264.jpg

Surface water flows along here. Though it is not running now because we have not had rain in a long time, it used to run on and off, seasonally and when we had rain. Now we grubbed out a channel for it to flow in:

http://i885.photobucket.com/albums/ac52/NHFamah/th_P1030265.jpg

And to catch the runoff from the hill, so that, hopefully, all of the water enters through the channel/waterfall:

http://i885.photobucket.com/albums/ac52/NHFamah/th_P1030266.jpg

And now, for the questions...any you KNEW there would be questions, didn't you???

1. What is the best way to deal with the ledge? In retrospect, I should have just dug the pond further down the hill and avoided the ledge altogether. Though with my luck, we would have hit another section further down and I would be in the same spot.

2. The location of the spillway is pretty set, since the guy from NRCS said it had to be on natural grade. But what about the beach? The view from the boulder side (left side) is much better than the view from the right side, so that was what guided me originally. But now with the ledge, I'm not so sure. Opinions?

3. I have boulders up the ying yang, so wherever the beach goes, I plan to construct a stone retaining wall to keep the sand in. Any different considerations for beach construction when using a boulder wall? Gravel? Sand? Underlayment?

4. Vegetation. This is the big question right now. Since I am going for maximum water clarity, I want to keep just about everything except for water out of the pond. This means no fertilizer/chemicals for the entire area leading down to the pond, nor around the dam. It also means keeping the washing of organic debris into the pond to a minimum. So...no mowing? I know I have to keep the dam somewhat trim to keep trees and large-rooted plans from interfering with the integrity of the dam, but as for the hill leading down to the pond, I want to avoid mowing as much as possible, since the cutting will wash right into the pond. So what to plant?

I just want to thank you all again for your time and insights. My contractor is not exactly a "pond guy," but with your guidance, we are both learning a ton.

Backstroke

I just checked my links, and the pictures are miniscule. My apologies. I am still getting the hang of this. Here are, hopefully, better links, in the original order:

http://i885.photobucket.com/albums/ac52/NHFamah/P1030259.jpg

http://i885.photobucket.com/albums/ac52/NHFamah/P1030260.jpg

http://i885.photobucket.com/albums/ac52/NHFamah/P1030261.jpg

http://i885.photobucket.com/albums/ac52/NHFamah/P1030262.jpg

http://i885.photobucket.com/albums/ac52/NHFamah/P1030263.jpg

http://i885.photobucket.com/albums/ac52/NHFamah/P1030264.jpg

http://i885.photobucket.com/albums/ac52/NHFamah/P1030265.jpg

http://i885.photobucket.com/albums/ac52/NHFamah/P1030266.jpg

Thank you.

Backstroke

Looks nice. I like the landscaping. I might be a little concerned about the steep banks. Depending on soil types, they may slide into the ponds bottom, over a period of time. Only time will tell if it holds water the way it should, as per our comments above.

When you copy the link in photobucket, take the one called IMG Code. It will put the photo in your thread.

Thanks, fish. Those banks are not the finished grade. They are going to start pulling them back once other aspects are figured out. And especially thanks for the photobucket hint. But the time I am finished with this pond, I will just have everything figured out!

Backstroke

I thought I had everything figured out but like they say "the more you know, the more you don't know". A lot of people on Pond Boss are very talented in this area. You can learn something new on this site every day. It might help your situation or might not. But at least you know.

Good luck with your pond!.... (I'd still think about putting a dock in there though).

Truer words have never been spoken.



I have so many boulders that I am hoping to build something like a dock out of them. They have been setting nice flat ones off to the side. With any luck, I will be able to dive off a nice flat boulder into the water, and maybe even have some sort of stairs for an easy way to climb back up. It's either use them, or find places to bury them.

Thank you for your thoughts.

Backstroke

You mentioned the area where the water runs into the pond. I can understand why you don't want to mow it for the sake it will bring in nutrients. I would keep that swale covered in some knid of fine material that will sift, filter, and hold the dirt that comes with the rainfalls. probably a grass of some sort, possibly a type that you don't mow often? Perhaps others here can guide you better on that.


Yours landscaped area that might turn out shallower than you want. I wouldn't worry to much about that until your water reaches the level where you know it will be at. Then, there are so many different plants, both water and terrestrial, that I am sure you will come up with something great.


Jim

Great ideas, fish. Thank you.

Backstroke