Proper Design & Maintenance

Pond management begins with proper pond construction. The best advice is to use an experienced pond builder who has a good reputation. Your county extension service can provide suggestions. The pond site must be suitable. The soil should have enough clay to seed well. The drainage area should be large enough to keep the pond relatively full of water even during dry periods. The emergency spillway allows excess water to "flood" around the end of the dam rather than over the middle of the dam. The emergency spillway should be wide enough to handle extraordinary rainfall. It should be flat and well grassed or otherwise stabilized to prevent erosion. The elevation of the emergency spillway should usually be at least 1 foot above the level of the standpipe drain and at least 1 foot lower than the top of the dam.

The proper equipment must be used to build the pond. Soil must be very well compacted. The dam soil must be at least 20% clay or have a clay core installed. The slope of the dam and shoreline should not be too steep. The dam, spillway and drainage structure must be well designed and built. In North Carolina, the pond must conform to the Dam Safety Law. (Contact the Land Quality Section of the North Carolina Department of Health, Environment and Natural Resources: 919-733-4574 for more information.) Often dams less than 15 feet high or impounding less than 10 acre-feet of water are exempt.

Existing ponds with an unbalanced fish population or unwanted species may need to start over. Renovation involves complete or partial draining, dam and bank repair, and removal of all existing fish. If the pond cannot be completely drained, rotenone can be used to poison the fish. Rotenone is an effective and safe chemical when used properly by knowledgeable professionals. You can be held liable if you are responsible for killing fish downstream. Rotenone is a substance made from tree bark that will kill fish without harming other animals. Some pond owners choose to drain an unbalanced pond and remove all of the fish. They then repair drainage structures and dig out accumulated sediment.