Pond Management: Site Selection
The first step in selecting a pond site is to determine why you want or need a pond. If you plan to use a small pond for fishing and irrigation or livestock watering, these uses will often conflict with each other. Pond uses that are more likely to work well together are fishing, swimming, boating, wildlife watching, and fire protection. If you need a pond as a water source for crops or livestock and you want a pond for fishing too, you may want to build separate ponds for each use.
In general, there are two types of ponds, embankment ponds and excavated ponds. Embankment ponds are constructed by damming a small stream. Excavated ponds are constructed by digging out an area fed by springs and runoff. Embankment ponds can be economically constructed on stream sites where the slope is steep enough to limit the size of the dam. Excavation ponds can be used in a variety of situations, but are typically constructed in flat areas where dams are not practical. Because excavation is very expensive, most ponds over one acre in size are embankment ponds. Before constructing a pond that either fills a wet area or involves damming a stream, contact the local U.S. Army Corps of Engineers (USACOE) office to determine if your planned construction requires a permit.
A good pond site contains all of the following:
- topography (lay of the land) that allows for economical construction,
- soil with enough clay content to hold water, and
- a water supply that is adequate, but not excessive, for the intended uses of the pond.
It is best to have several site options that are appropriate for the planned uses of the pond. Ponds with dams over 20 feet in height are costly to construct and do not typically provide higher fish production due to the loss of oxygen in the deepest part of the pond in mid-summer. In Virginia, ponds should have dams high enough to provide a depth of 6 to 12 feet. Productive fishing ponds usually have 20 or fewer acres of watershed for each acre of pond. Advice on pond site selection and construction is best obtained by consulting with your local offices of the U.S. Department of Agriculture, Natural Resources Conservation Service (formerly known as the Soil Conservation Service) or the Virginia Cooperative Extension Service.
The water quality in your pond will vary according to the land uses and geology in the area from which the pond receives runoff (the watershed). If your pond's watershed is used for grazing or crop production, or if it is a dense urban area, poor water quality can result if runoff from the watershed is not filtered before it reaches the pond. A vegetated buffer strip at least 50 feet wide surrounding the pond can serve as a natural filter. If your pond is fed by a stream, the stream should have a vegetated buffer strip along both banks. Livestock must be fenced out of streams above ponds and out of the pond itself. If the pond is being developed for livestock watering as well as fishing, create a livestock water source downstream of the dam.