reconditioning natural lake suitable for swimming

Hi everyone!😊


I would like to know what is the best way to recondition/refurbish the lake hydraulic basin so it can be suitable for swimming? A sustainable solution, that allow us to use only and always natural materials and to keep it under the budget!, it is a huge extension...


I will be very grateful for all the help i can get!

What is its current condition, and what do you need to accomplish?

Does it hold water? Are there contaminants that require bioremediation, as in fungi, heavy metal-accumulating plants, and reed and pond-edge filter plants?

If you could fill in some details, including perhaps some pictures, any advice offered would be closer to what you're looking for.

-CK

Chris Kott wrote:What is its current condition, and what do you need to accomplish?

Does it hold water? Are there contaminants that require bioremediation, as in fungi, heavy metal-accumulating plants, and reed and pond-edge filter plants?

If you could fill in some details, including perhaps some pictures, any advice offered would be closer to what you're looking for.

-CK

Hi Chris!, thank you for your reply! I will try to reply accurately to your questions!

The lake holds the water, the land is on slate soil so i can say that the hydraulic basin waterproofed itself! It has no reed or pond-edge filter plants! Despite containing, fishes, frogs, dragon-fly's, etc, we will mandatory have to clean it, clean the bottom for trash that people left their for years and the accumulated sludge's, regarding the water quality, the lake is fed by an unpolluted river.

 I think i can say that the lake is in the bottom of a kind of a "valley"!,  we have a surrounding walk-path around the lake, and right next to it we have two "half-slopes".
It needs deep cleaning due to human action (by trowing trash in to it) and also nature, in winter times, all the debris brought by the rain (soil, vegetation, etc), come down hill and set up in the bottom of the lake.


The intention is to have a clean place for people to be able to swim in.


Patrícia


ps: sorry for the spelling mistakes

I think this requires a two-stage process, perhaps three.

You want to physically remove any man-made garbage you can, I think. Any natural detritus should probably be gathered to accumulate more along the banks seasonally.

I think the key part of making it swimmable is to ensure that those areas of shoreline that can be left for nature be transformed into natural reed beds. Incidentally, reed beds could act as sediment traps along the shoreline if properly situated. They will also clean the water.

This sort of debris usually form sandbars, which can then be colonised by reed bed species that will in turn accumulate more sediment and organic debris. This is infinitely better than having sediment silt up your lake.

-CK

If I were you, I'd get a map and a sense of the larger watershed before going too far with any downstream project at the lake.  Where is the water coming from?  Can you walk the waterway that feeds your lake and go upstream for a couple of miles to see what is flowing down into the lake?  Is that water being filtered along the way?  Are there people willing to cooperate on this project, even though they live miles upstream?  You need a macro view of the situation, not just a lake-side view.

If you can filter the incoming water to the lake by passing it through a bio-filter that pulls most of the sediment and perhaps even bacterial contaminants from the water before it reaches the lake, that is best.  The most natural way to do this would be for beavers to colonize the river above the lake, and create a series of wetlands to slow the incoming water.  Beavers cause the water to pass that water through large beds of reeds and other plants.  Beaver-created wetlands also capture biomass like leaves and decomposing plants before they wash downstream and sink to the bottom of your lake.  Obviously some leaves will filter through, but you won't have as much biomass sinking to the bottom of the lake and making a stinky anaerobic goo down there.

If the bottom of the lake is full of nasty stuff, dredging is expensive but it would be one way to clean it up.  Perhaps you could just concentrate on just dredging the area where you want to create the swimming area/beach.  Dredge that area out, haul in some sand and make it nice.

If there are bacterial contaminants coming from farms upstream, that's a whole different challenge.  You need to stop the poop from washing down the watershed long before it reaches the stream.  Giardiasis is sometimes called "Beaver Fever".  It's caused by fecal matter from humans and other animals washing down into lakes.  Your lake may be "swimmable" but that's not enough if every kid comes home sick following their day in the water.

https://en.wikipedia.org/wiki/Giardiasis

https://www.health.ny.gov/diseases/communicable/giardiasis/fact_sheet.htm

Most states have all sorts of environmental regulations about discharge washing off of animal operations and down into the watershed.  You may need to call the man and have them enforce these regulations if that's a problem.

With a body of water that large, you're almost certain to get in trouble if you just start making alterations without contacting the proper authorities. This isn't a small farm pond, and it doesn't appear to be man-made. You'll probably find that there is plenty of free information and sometimes money available for this sort of thing. In many places, those who caused the pollution could be made to pay for it, even if they are no longer on title. I would check out all legalities before doing anything.

Hi everyone;


I will read carefully all your comments and will get back to you. Meanwhile I will also go to the site this Saturday. I will come back after, and will give you a detailed feedback.



Thank you!

Notwithstanding the water quality issues related to upstream activities, I suggest dredging will be a major problem - it's also possibly one of the things the local environment organisations will prohibit.

Dredging disturbs accumulated toxins and heavy metals that would otherwise be relatively safe when left in situ in the mud.

Dreading also increases turbidity, which can reduce oxygen levels, and impact the lakes ecosystem.

It's likely they will request a rehabilitation plan that excludes major disturbances.

If the lakes edges are mud, not sand or gravel, perhaps a series of 'environmentally sympathetic' jetties would allow swimmers access to the water without clambering through and disturbing the mud.