I have a 2/3 acre spring fed pond in SE Minnesota. It was originally excavated in 1989 and has a maximum depth of 9 feet. It is located in my parent's elk pasture and receives the high nutrient runoff. My parents no longer have the elk but the pond has become overrun with vegetation. Originally, it was overgrown with sago pondweed, elodea, and filamentous algae. Thus, I installed an aeration system with two bottom diffusers and have used bacteria to clean up the pond.

Now, cattails and duckweed have moved in and I can no longer fish from shore. I am hoping just to dredge the shoreline deep enough to limit the vegetation growth. The past couple years have been so dry that the water line has dropped below the weed line during the summer. Would it be necessary to drain the pond in order to dredge it?

The pond has some bluegills, crappie, LMB, SMB, walleye, and a couple unwanted bullheads. I am afraid if I dredge that the only thing that will survive are the bullheads. Will dredging harm the fish?

I am looking for any input/opinions on my situation. Also, does anyone know of a good dredging/excavating company in SE Minnesota?

Thanks,
Kasey

You can probably use a back/trackhoe to excavate close to shore, deepening the edges and leaving a steeper slope under the waterline so as to reduce the available habitat friendly to cattails. I have seen posts/pics of this being down with water still in ponds. I don't believe there is a major risk to the existing fish population; there will be some sediment introduced to the water column during such renovation, but if only one 'hoe is working at a time it will be somewhat limited.

I don't think shoreline work will have a major affect on DW.

Dredging is a great way to deepen areas of a pond without emptying it or ruining the water. It's best done on mud, as solid dirt or clay would be hard to dredge. It's very work-intensive, so it's best for small areas.

Kasey, be careful if you use Theo's trackhoe...

I really miss that truck.

That's what happens when you make the wife mad. You weren't sleeping it off in the truck were you?

Thanks for the information/suggestions. The cattails extend almost 30 feet from the shoreline into the pond. Do you think a standard backhoe would reach that far?

I have never had a problem with DW until this past year when the cattails limited the wave action on the pond. There were days when the DW covered the whole pond except for the 20 ft diameter openings made by my two diffusers. Do you think I am at risk for summerkill if the DW continues to cover the pond even with my aeration system?

I purchased some bacteria this past week and intend on using it to limit the nutrients. Do you think I should buy some herbicides to control the DW just in case?

Thanks again,
Kasey

You'd be lucky to get half that far with an extendahoe. A normal backhoe will get 12 feet or so, but that's from where it's parked.

Even if you bring in an excavator to take them out, they will just come back again. Poison is about the only sure fire way to get rid of cattails.

Eddie

What about useing a box spring weighted with a tractor pulling it? Take a piece of pipe and run it through the boxspring, hook a chain through it and start pulling. It can be done, I know I have done it to a couple of friends ponds. To get out further you have to use more chain and it is labor intensive but,it dose work. You can pick up a boxspring at salavation army for near to nothing , burn it in a fire and the rest is easy.We have even used 3-4 boxsprings at a time wired together. Get ahold of some friends and tell them you'll buy the beer and have a cookout..lol

Here are some pictures of my pond before it was dredged. Notice the dense growth of cattails and duckweed. A dragline was used to steepen the shorelines and remove muck.

After 2.5 days of digging, my pond was finished and I am very pleased with the results. The cattails are gone and the fish survived. Now I just need some dry weather before I smooth out the dirt. I realize the growing season is pretty well over with here in MN but is it still possible to seed some grass and prevent the dirt from washing back in? If so, what type of grass would be best? Here are some pics of the final product.

Kasey, the pictures didn't show up here - all I got were the blue squares with "?".
Sounds interesting and would love to see the pix, but can't get them.

Can anyone else see them? I can see them just fine. I followed the guide on how to post pics with the exception that I used Kodak Photogallery.

All I see is the dreaded red X.

I see pond pictures...

Man! That was a lot of cattail!

I just see red "x's"

You have to stare at them for a few minutes...

Kasey, did you treat for the duckweed? I see you still have a little but it's much less than before.

Okay I edited all my pics with Picasa and hopefully everyone can see them now. Let me know if you cannot.

GW, I did not treat the pond for duckweek. This late in the growing season, I am hoping it will die off on its own soon. My intentions on dredging the pond was to steepen the shorelines with the hopes of limiting the vegetation growth. The cattails were limiting the wave action and allowing the duckweek to cover the pond. I was afraid that one day the duckweed would cause a summerkill by by not allowing sunlight penetration. It should be interesting to see what grows back in the years to come. I was hesitant in the past to use herbicides on the pond because my parents' elk may sneek into the pond and drink the water. Now, they no longer have the elk and I will resort to herbicides to control the vegetation.

The pond is located in what was the pasture and now is a corn field. It has always received excessive amounts of nutrients. We have been treating it with bacteria to clean up the muck and nutrients and it seems to be doing an acceptable job. This is the first time in 18 years that the pond has been dredged so I guess I can live with that.

Now I just need to get some structure back into the pond now that all the cattails are gone. I went around yesterday and threw all the rocks back in that were dredged out. My back and arms are feeling it today.

I can see them. What a difference.

What can you say about the fish, before and after?

I went fishing on Wednesday and Thursday and the fish bit well. Also, I set my fyke net overnight and caught approximately 10-15 walleyes, 20 crappies, and 40-50 bluegills so I assume the fish survived just fine. Although we didnt catch any bass by net, we managed to catch a couple with a hook and line. The water is still murky so it has been difficult to see much with my underwater camera.

I was scared to dredge the pond because I was unsure how the fish would survive but I figured it was better to lose a few due to dredging than to lose everything due to a summerkill.

Ah, now I see. Very nice!

Kasey, I just went through the same thing with my pond. I had some shallow weedy areas I wanted to get rid of and expand the size. I rented a rather large excavator with wide tracks, two yard bucket. It did a great job of digging the muck and peat/cattail roots out of the pond. Most of my pond has steep edges which has worked great to control weeds. I too was very afraid that the low water level that turned to chocolate milk would kill the fish. They made it through fine. Nice to hear from another MN pond owner. I'm afraid that if you have high nutrient levels caused by past elk herd and by your fish you will have a duck weed problem. I'm afraid to use chemicals to kill DW in muy pond because we eat the fish. I don't care what anyone says it can't be good to eat from water with herbicides in it. Looks to me like your pond would be the perfect place to use the Pond Boss prickly rope. Some posts on that approach can be found somewhere amongst the "controlling unwanted plants" topic I think. You should give it a try next year.

I really want to thank Kasey and BZ for posting their work.

Since last spring I'd been planning on cleaning up the edges of my pond in August or early September, when my pond is usually at least a foot lower than the standpipe. Even with our so-called drought, we had a number of significant storms from early spring until now that dumped a lot of water in very short periods of time. Consequently, my pond has stayed plus/minus a few inches of the standpipe level all summer.

Anyway, I had a lot of willows that had sprung up around the back edge of my pond over the last couple of years. More cattails than I feel comfortable with were creeping in, and I'd been wanting to clean up some former erosion inflows that had become quite shallow.

Thanks to you guys, I put the backhoe on my tractor yesterday. I spent this afternoon excavating the worst corner of the pond. I pulled out several willows, several old stumps on the shoreline, and I dredged the edges where there was a lot of muck. I figure I temoved about 30 yards of mud and muck over about 50 feet of shoreline. I now need about three more afternoons, before winter, to finish.

I was amazed at how fast the water cleared. I created four smelly spoils piles. By the time I got them moved and spread with my loader bucket, the pond water looked almost normal. My one big koi, and at least one of my larger surviving medium-size catfish was checking it out as I was on my final spoils load. That was just before sundown. I did my normal evening feeding across the pond, and all the fish seemed happy.

Uffda!

Ken