By: David T. Lemke
Civil Engineering Technician
Natural Resources Conservation Service
A pond in good repair is a valuable asset. It serves as a water supply for livestock, and for other domestic uses, as a fish and wildlife habitat, and as a recreation facility. A well-maintained pond may also be useful to the owner as a source of water for rural fire fighting. In the event of a disaster, perhaps only minor damage will occur if water is readily available.
An estimated 125,000 ponds have been built in Kansas which amounts to almost 5% of the national total of an estimated 2.5 million. Over 75% of all farm ponds are primarily for livestock water. Other uses include fishing; wildlife habitat, recreation, flood control, and as mentioned a source of water for rural fire fighting. Typically, farm ponds are small, and where originally intended only for a single purpose, but with today's technology, and some improvements, your farm pond may be useful for several purposes.
Regular inspection and maintenance are required for ponds in order to maximize a pond's usefulness and value. Lack of inspection and prompt attention to repair has resulted in irreparable damage to many dams and spillways making the pond totally useless. Long before irreparable damage occurs, simple and inexpensive repairs will extend a pond's useful life. These repairs also give the pond a well cared for look that makes it a visual asset rather than a visual pollutant.
The earthen embankment is a the key part of a farm pond. The embankment should be maintained in height and top width. It should be protected and maintained to the original deigned measurements. A good vegetative cover is a must to control rill erosion that is a common problem. Regular inspection will detect any erosion or inadequacy. Sometimes fertilization, pesticides, or reseeding are required to achieve and maintain a vigorous grass cover.
Livestock damage is another common problem. Check and repair any fences that you may have around the pond or dam to exclude the livestock. When livestock have access to the embankment, they tend to destroy the vegetation cover on the dam and cause physical damage resulting in erosion to the structure. This damage should be repaired and the damaged areas reseeded as soon as possible.
The earthen spillway, cut into the soil at one end of the dam, carries peak flows around the dam, and protects the embankment from damage caused by possible overtopping. This emergency spillway is usually two feet below the top of the dam. Livestock trails in the grassed emergency spillway, another common problem, lead to an eroded spillway, and possibly, the most serious threat to the farm pond.
The overflow pipe is below the emergency spillway crest, usually by a foot or two, and provides an orderly release of water down to the conservation pool level. Its function is to protect the emergency spillway from extended wet conditions resulting from excessive use. The overflow or principal spillway tube should be checked and cleaned as required to insure that it is open and the flow of water is unrestricted. Also check the tube outlet for erosion or scouring and correct any problem when it is first observed.
Trees can be a problem around ponds, especially if they are allowed to grow on the embankment. They reduce the grass cover and provide a habitat for animals that damage the structure or pond edges. All trees should be removed from the embankment when they are small, and before they develop a deep root system. Trees back from the pond or below the dam are acceptable but often serve as a seed source.
Excess vegetation in a pond can be a result of excess nutrients running in the pond from livestock, septic fields or applied fertlizer. Other contributing factors include shallow areas of a pond, less than 3 feet, that allow sunlight to reach clear to the bottom of the pond. And clear water that again allows sunlight to reach greater depths. In both causes the sun stimulates planr growth. "Aquatic Plants And Their Control" available online from K-State Research and Extension (Search for "Aquatic") is a good source for suggestions to control excess vegetation. And by the way, grass carp only eats leafy vegetation not the stringy moss.
Muddy water can be a result of wave action against exposed shoreline or from soil erosion into the pond. Maintain good shoreline vegetation and take measures to control all forms of soil erosion above the pond. In some cases if the water remains cloudy placing a few bales of hay or straw in the water can help clear it up.
Sediment accumulation will in time make a pond useless. The rate of accumulation is directly related to how good a job is done to protect the land above from eroding. But in time either dredging or rebuilding the pond might be necessary.
A well maintained pond is useful to the owner, and is a thing of beauty. But a poorly maintained pond is an eyesore.
Newer technology has brought about better quality overflow pipe, particularly PVC plastic pipe that does not rust, more stable emergency spillways, and such things as dry hydrants for improved capabilities in rural fire fighting. Contact your local Natural Resources Conservation Service office or the District Conservation office for more information in farm pond maintenance, and the possible use of your farm pond for improved rural fire fighting capabilities.
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