Pond Boss Forums POND CONSTRUCTION Renovating a Pond or Lake? I think I made a huge mistake...

I want to say that I have read a bunch of threads on here (after we recently built our pond) and I am realizing that I did not do nearly enough homework on this before building... There isn't much I can do about that now, but would like to try to get some feedback on my current situation.

We had a 3 acre pond dug out last fall. At the time, we paid a ton of attention to what I will call the "main body" of the pond, which is about 2 acres, because that was the original plan. However, after getting started and continuing to have issues with a large marshy wet area, we decided to just raise the dam and let that area flood, essentially adding an extra acre of water surface.

HOWEVER, we didn't really do anything to that area other than scrape off the topsoil and let it fill with water. Because of that, a large part of this area is 1 to 2 feet deep. I am know realizing we should have dug this section deeper, as I am now seeing a lot of algea, and realizing that I have ~33% of my pond surface are at less than 4 feet, and probably half of that is less than 2 feet deep.

Here are some pictures to help explain the issue....

First images are what I am seeing from shore now. I am also seeing large clouds of algae over on the deeper end of the shore, but only in spots along the dam. Separately, there is a large area of lily pads growing in the middle of the pond, but that area is at least 5-6 feet deep? Pics from the bank and the middle area below.

My question:

1) Are there things I can do to make this work as is? Will this be a constant algae fight that I can't win, or could this be controlled with some chemicals. Will those chemicals hurt the fish? Pond is not used for drinking water or irrigation.

2) Should I drain the pond down a few feet now, and have someone come in and dig this out? I feel very stupid for not having done this previously, but trying not to dwell on that. The only good news is that I think if I drain it now, the muck should dry fairly quickly, and possibly be pushed with a dozer into the sides to create a reasonable "bank" all the way around the shallow areas. This will be an expensive dumb mistake, and I don't really want to go that route, but will if there are no other options to get what I want. How long would this take to dry? There is REALLY good clay underneath all of this area, so that is not a major concern.

3) Other options I haven't considered?

Thank you to anyone who takes the time to help. As I said, I am sick at this point worrying that I really screwed up, but need some help from more knowledgeable folks to determine the best way forward.

My goals for the pond are primarily fishing (want to stock with bluegill/CC/LMB), but I would like it to be clean enough for my wife to feel comfortable going out on the paddle board etc. (not a ton of green floaty algae in there) and I would Love for it to look like as amazing as it does in the springtime pic below...

James

It doesn't appear that my images came through, so I put them in a google folder here:

https://drive.google.com/drive/folders/12mj8A90q76XVuCI7lLUBNQozgqBbpZCf

James, almost always the cheapest way to deal with this situation is to raise the dam. Of course, that might not be feasible for you, depends on a lot of factors.

If you must move muck, probably cheapest is to make islands by scraping up shallows into high spots so you'd have deeper water without having to push it all the way to the bank. Idea is to minimize dozer time for maximum effect.

Best of luck! We all have made mistakes, it's part of the learning process.

That 'shallow' area doesn't look too, too bad, and it will be usable by a lot of different fish.

In general, the amount of plant life has a relation to how much nutrient load is in the pond.

You can use certain chemicals to treat certain types of vegetation, and you can do it selectively and gently to not hurt any fish.

I'd wait and see how things go. There could be an option to introduce sterile/triploid grass carp to deal with vegetation down the line, but that will depend on what exact vegetation you have.

Another option to help a little bit is to get an excavator with the longest boom possible, and excavate a deeper trench all around the perimeter of the shallow area. However, you'd have to make sure you don't dig into dirt that won't hold water.

If I understand correctly, the dirt in your shallow areas will just be mud, not a collection of old silt. I believe silt would be a lot harder to move - if you can lower the level enough to let the mud flat dry out some and allow the mud to dry out some, making islands will be a lot easier than if you were trying to reclaim an old pond that had silted up.

Sounds like life gave you some lemons, time to make some lemonade!

One option would be to use your shallow area as a giant bio-filter to clear up your "main pond".

Right now it appears that there are very few rooted aquatic plants in your pond. Therefore, all of your nutrients are being utilized to propagate filamentous algae (FA) at this time.

Hopefully, as your pond develops some aquatic rooted plants, your abundant FA will be somewhat reduced. So your pond should change at least a little, moving forward in time.

However, if you want to do some dirt work to improve your main pond, you could drain the pond down a few feet and push up a levee to separate the shallow area from the main pond. You could add a relatively small transfer pipe (4-6") with a valve - if your surface runoff does not preferentially fill the shallow area

I would then plant rooted aquatic vegetation to soak up the nutrients. Especially if you can easily control the water level in your pond. One option would be to run it like a duck hunter pond. Pull the water level down, then seed it with rice or millet. Re-flood the area and then set up a circulating pump to move water from the main pond to the back of your shallow water area. The nutrients in the main pond would then be utilized to growing your "crop" in the shallow water area, instead of growing FA in your main recreation pond.

The levee does NOT have to be built in lifts and compacted to seal between your two pond areas. However, it does need to be constructed well enough to avoid wind/wave erosion. Maybe sling some aggregate on the banks to make it attractive and erosion resistant?.

There are lots of different plants you could use besides the "duck pond" plants. If you contemplate my crazy idea, maybe start a new thread and get some actual expert advice on beneficial plants that would work for your pond conditions in a Kansas climate. Perhaps you could do the whole thing in lily pads, if there was some cultivar that only spread by root propagation and would not cross the levee?

Congrats on your nice, new pond! Good luck on the improvements that will make it more enjoyable to you and your family.

If it was my pond, I'd lower the water level, get a long stick excavator and make that area deeper, but only go 3' to 4' deep max, at a taper from the 1'-2' depth now. It won't be a huge amount of dirt to move. That area will be a great biofilter once you have underwater weeds starting to grow in the pond. I'd leave that area weedy, as a great habitat for fish. Perfect spawning area, and a great habitat for the young fish. That much underwater weeds will help keep the pond water clean by utilizing a LOT of nutrients. Maybe put down some geotextile fabric in 2'-3' water and put a dump truck or two of pea gravel down on top of the Geotex, about 8"-10" thick. Fish will really use that area to spawn.

At this present time, it is growing a lot of algae. That will change once you get underwater plants established. Sago Pondweed, American Eel grass, etc., etc.

Once the weeds are growing Leave them, if anything, spot treat some areas to leave some open paths - fish like to use the edges of weedbeds.

Everyone, sorry for the late response here. Been crazy busy at work and haven't been able to work on or think about the pond much.

I appreciate everyone's time to respond, and will try to address a few of the questions, thoughts below:

Anthropic - I have no ability to raise the dam based on how this sits on the land, proximity to other stuff, etc. The island idea is great. I don't think I would have a TON of dirt to move either way, and not much sludge due to it being a newer pond, but if we decide at some point to drain and dig, I definately will keep this in mind and see if we can incorporate that to save work and make a cool visual feature.

Sunil - The "wait and see" approach is where I am currently leaning. I did a depth check, and there really isn't that much under 2'. A lot between 2' and 3'. I think maybe some pond dye, some Grass Carp / Tilapia, and some chemical treatments along with manual removal may be fine without any draining. If I do have to dig, I'm not worried about hitting dirt that doesn't hold water, the clay in this particular area is amazing.

Theo - Correct, this would be dirt, not old silt. Should dry out and be moveable pretty easily... Not sure how much a long reach could get to, but after playing in the pond a bit with the depth finder, I really only need to get out 20' or so. A normal excavator could probably get the vast majority.

FishinRod - I like where your head is, but not sure I'm ready to try to manage another area. There is already a pretty shallow silt pond upstream from this on the left of the pictures. Not sure how I would manage that in between the three. However, I do think I need some plants to eat up the nutrients. Doing more research on that now.

esshup - I think I need to learn more about how to establish underwater plants. The more I read about it, the more I think that area will work great for that part, once I have the nutrients going to those plants to clean up the water, vs the algae. Just not sure how to facilitate that kind of change in the ecosystem.

My current goal is to manually remove as much algae as I can over the next couple weekends, using a diy rake system I'm building tonight using some scrap railing from building my deck... Once I remove everything I can, I'm going to try to figure out how to plant some of the underwater plants esshup mentioned to help use up the nutrients, etc. Then I'm goign to likely dye it to keep some of the sunlight out, add some grass carp this fall with the bass, and see how it goes. May try to add some chemicals to attack the algae next spring as well.

If I can keep the algae down without Hurculean efforts, I'll feel good about it this year / next spring. If not, I can always drain/dig as necessary next year or the year after...

JMH

When I built my pond I had a big area, probably close to an acre, that was going to be a shallow flat, only a couple ft deep, so I pushed the topsoil off to the side and pushed a lot of the dirt together to form a little island of sorts, then pushed the topsoil up to the top of it, flattened out the top of the island, several ft above the water level.

I did leave a strip of dirt to connect the island with the mainland so that predators can get out on it and help me control muskrat and goose populations, also I can drive a machine or tractor out on it for seeding and mowing and maintenance purposes. My plan was to eventually dip out the strip of dirt to make it an actual island but I have changed my mind, think I will leave the connection to the mainland.
Point being, by doing that I have cut down on my pond weed problems by making the area around it 5' to 6' deep, not to mention the extra shoreline it creates and also a really nice fishing spot, except for this being way back in the backside of the pond and and a lengthy process to get to.