Ground water is basically free of nutrients and organic materials. You can clay line your pond so you can also utilize runoff and probably maintain a more stable water level than the water table itself.
If it is possible and acceptable to leave the sand bottom and let the water table dictate the pond level, cutting out runoff altogether will usually produce better results nutrient-wise.
Clay lining the pond and well filling it, and also shaping surrounding contours to prevent run-off fill, will accomplish the same thing and may allow you to maintain a level above the water table.
Make sure you do the math and see what type of gallons per hour you will need on that well to raise and maintain the pond level. I do weed and algae control and a large part of my market area has beautiful beach-sand soils and a high water table.
Thousands of ponds have been dug into the sands and almost none have problems with vegetation (at least not if they are fairly deep). In another part of my market area the soils are 100% clay and the water table is deep. All the ponds are filled by runoff. Almost 100% have chronic problems with filamentous algae growth.
Yet another area has predominant clay and a high water table (and wise contractors) ponds are filled by the water table and levels are maintained by well. The spoils are mounded around the pond to prevent runoff filling, again-no algae problems.
There is no better filter than soil. With groundwater fill your water is very clean. If you have runoff into the pond utilize vegetation as a natural filter. If you want a natural pond, go look at some. Look at oxbows or small glacial lakes on nature preserves where disturbance has been minimal. Water quality will generally be good. Buffers of natural vegetation surround most natural lakes. Upland forest, wetland shrubs, sedges, grasses, then as you go deeper into the water, bullrush, spikerush, arrowhead, white and yellow lily, Pickeralweed etc.
It is difficult for nutrients and organic materials that lead to poor water quality and clarity to pass these natural filters. Instead they become invested in the biomass of the filter strip and strengthen it more. These are the conditions you want to try to recreate in your pond.
I constantly perform algae treatments on ponds because people want a nice manicured fertilized lawn right up to the edge all the way around the pond. Ironically many people maintain their pond's watershed this way and then object to the use of chemical controls because they are not natural! I remember one full-season customer we had. The edges of his pond were so overgrown with brush and shrubs you couldn't see it until you walked down a narrow path to his dock. We never had to do anything there, the water was always crystal clear and floating algae mats were never present.
It's always a trade off, but if your pond will collect run-off I would at least try to establish some emergent aquatic plants around the edges and leave a 4 foot wide strip of uncut grass around the ponds edge.
Water circulation is great if properly induced. I won't go into the chemistry involved, but a bottom based compressed air diffuser system (diffusers placed in the deepest areas) will break up the stratification of the pond and help lock nutrients into the hydrosoil. Both electric and wind powered systems are available.
Emergents are all excellent plant life. Root stock can be purchased, but I usually pull plants from natural lakes and marshes and transplant them. If you do this try to avoid transferring unwanted plant species or hydrosoils along with them. Otherwise you may end up with an infestation of a dominating exotic species.
Always remember that you are trying to recreate a natural lake with a minimal amount of disturbance, so observing such areas near you is helpful. Keep in mind also that nature sees your pond as a disturbance, so disturbance oriented species will attempt to colonize it's edges very quickly. That will provide filtration but it is not what you really want.
Try to avoid and discourage the following:
Cattails, Reed Canary Grass, Phragmites, Water Willow.
For submersed aquatic plants, stout and large leaved members of the Pondweed (Potamegeton) family are your best bet. In Virginia, avoid hydrilla at all costs, it will take over and prevent a diverse plant community. If you don't plant submersed aquatics they will eventually appear on their own. I often see them in new ponds in the first season. Fertile propagules ride in on turtles, waterfowl, etc.
The biggest problem I see with your (specific) plan is your depths. Way too shallow. Your going to have major problems with excessive vegetation. You need to keep the majority of your hydrosoil deep enough to be out of the photic zone.
In your area I would strongly recommend excavating at a three to one slope on all sides to a depth of at least 8 feet. If you can go deeper, even better.
As far as fish go, the bluegill-largemouth-catfish combination is hard to beat. Try to maintain a catch-and-release policy on largemouth bass, otherwise you can end up with a huge population of stunted bluegills. If you want a good initial growth spurt introduce fathead minnows first and provide some sunken wood pallets and large clay field tiles for them to spawn on. The field tiles may also give your catfish a place to spawn. The minnows will begin spawning in early spring and continue through the summer. You can feed them by having a grain elevator grind up catfish pellets into a powder and tossing the fine food into the wind allowing it to drift onto the pond. Toward the end of the summer when their fry are running pretty thick, stock your fingerling bass and blugills and it's bon apetit.
I know of a couple publications that could be helpful to you,
drop me a line via e-mail if your interested.
Best of Luck!
Reds: mailto:aquatic@dmci.net |
Koenders Pond Aeration Windmills | Electric Aerators |
