Summer is often the time folks begin construction of new ponds or renovate old ones. So, for today’s article, I thought it would be useful to discuss some of the basics of pond design. This information is excerpted from our excellent Pond Management Guide.
The best fishing ponds have a surface area of at least an acre. Ponds of less than an acre are difficult to manage because the fish populations — especially largemouth bass — are easily over-harvested. In addition, small, shallow ponds are susceptible to vegetation problems that usually result in overpopulation of sunfish. These problems ultimately result in stunted growth of both bass and sunfish.
The fish populations in ponds of less than an acre are also hurt by drought. If you have a small pond and cannot afford to enlarge it, the best management tactic is to stock it with a single species of fish, such as channel catfish or hybrid sunfish, and begin a feeding program.
The average depth for a 1-acre or larger fishpond should be between 6 and 8 feet with a maximum depth not greater than 10 to 12 feet. An average depth less than 6 feet greatly increases the probability of aquatic vegetation establishing in the pond. Depths greater than 12 feet are not necessary for good fish production, and are more likely to experience fish kills from summertime oxygen depletion. Pond banks should be cut on a 3-to-1 slope and should be a minimum of 3 feet deep at the waterline before leveling off. This shape will help prevent the growth of nuisance aquatic vegetation and will also discourage muskrats.
An important feature that should be incorporated into the design of all fishponds greater than 1 acre is a water control structure — a drainpipe. A drainpipe enables you to drain the pond to make repairs, fix leaks and control nuisance aquatic vegetation. It also makes it possible to treat and remove undesirable fish species chemically and to manage the fish population more effectively. In addition, a drainpipe that incorporates a bottom draw-off device ensures good water quality and reduces the chances of a fish kill by removing stagnant water from the bottom of the pond. Ponds tend to stratify in summer and winter, resulting in a stagnant bottom layer that is low in dissolved oxygen and may contain high concentrations of toxic gases, such as carbon dioxide, hydrogen sulfide, and ammonia.
Another important feature that you should incorporate is an emergency spillway. This structure is designed to prevent loss of the dam during periods of extremely high water by rerouting excess water through a low spot over or around the dam. To meet individual requirements, it is best to ask your county Natural Resources Conservation Service for advice about this aspect of pond design. Contacting the appropriate agency when first considering construction of a pond can prevent many costly mistakes.
Information for today’s article was developed by N.C. State University Fisheries Specialist, Jim Rice and can be found in the Pond Management Guide online at www.ces.ncsu.edu/nreos/wild/fisheries/mgt_guide/. For more information, contact Mike Frinsko, area aquaculture agent, Jones County Center at 252-448-9621 or at email@example.com. Or visit http://robeson.ces.ncsu.edu.