New member looking for advice! Western North Carolina neighborhood (50 homes) HOA lake (2 acres) hasn’t been dredged in 30 years. There is algae/vegetation building up in the middle and around the perimeter of the lake. Very minimal creek flow into and out of the lake.
Original community residents claim it used to be 12’ deep but now is 6’. Should I focus on chemical treatment, or maybe aeration/fountains, or would a $200,000+ dredging project solve it better in the long run?
Not the answer you want to hear, but a mature, fertile lake in NC is going to support lots of something that utilizes photosynthesis. Your problem is made much worse by the middle of the pond only being 6' deep. Sunlight is probably reaching the bottom of the entire pond for most of the year.
Chemical treatments will knock back the aquatic rooted plants and/or the algae, but the nutrients will remain in the pond - so you will face the exact same battle in the very near future.
Heavy aeration can slightly reduce some of the build-up on the bottom of the pond, IF a significant percentage is organic material (as opposed to silt) and you get some substantial bottom agitation to get the organic muck up into the oxygenated water column.
You might have a cheaper solution than dredging, but it will be ugly - so I don't know which way the HOA would prefer. That option would be to drain the lake, breach the dam, and push the silt through the breach. Or perhaps have an excavator deepen the middle and spread the spoils up higher in the pond so that they may dry.
It is not as simple as it sounds, since up to 6' of muck will NOT initially be workable by a dozer, so you may have several scrape/dry episodes (over the course of a year?) to achieve the depth you want. You also need some place to spread the spoils so they will dry, and can then be subsequently moved or built into a berm.
Just throwing out some ideas for you to chew on. Hopefully, some experts will chime in with some more specific advice.
FishingRod - IMO provides several good ideas. A shallow mucky pond is loaded with problems that will not be cheap to fix. Ponds are collection basins of everything that entered and enters that basin. Nature's goal is to fill in in with muck to create a wetlands and eventually dry land. This is called "aquatic succession". It may take 100's of years, however it now has a good start to continue toward the goal.
aka Pond Doctor & Dr. Perca Read Pond Boss Magazine - America's Journal of Pond Management
Rod, the dredging project doesn't have to drain the water out and leave it dry for heavy equipment. They can pump the water into dewatering bags or pump it to a holding pond on a nearby field, let the sediment settle out and let the clear water back into the pond.
The level of the pond will be lower while the dredging operation is happening and less low with the dewatering bags than with the holding pond.
Copied and pasted from original thread.. I think it needs to be here..
My first thought is I don't really see any beneficial type aquatic vegetation, like bulrush, arrowhead, etc. The older a pond is the more nutrients there will be-in general-if there is nothing present to "use" the nutrients. I see some filamentous algae growth-which is locked up excess nutrients, but a vicious cycle. You can kill it, but as it decomposes, nutrients are re-released back into the system and repeat. Aeration does not inhibit algae or aquatic vegetation, in fact in some cases I believe aeration can keep some sediment in suspension and make agal growth worse-there are ways to lesson that. We (I or anyone making an educated guess) need to see some samples of plants from the pond on a white-ish background (bottom of a 5gal bucket) to see the type of plants you have and ID them correctly. If you can post a pic or 2 of that, we can determine actual type and go from there.
