Water Sources: Pond Fencing
Overview
Ponds can be important sources of livestock water and serve other purposes such as runoff retention, erosion control and aquatic wildlife habitat. Most ponds lose some usefulness over time due to erosion and sedimentation. Eliminating unrestricted livestock access to the pond with fencing can extend its useful life. A fenced pond requires an alternative method of allowing livestock to use the water, such as installing a pipeline through the dam to a tank or construction of a limited-access ramp to the pond. Rotational grazing of the pasture may also provide some of the same benefits as fencing, as livestock are limited in the amount of time spent in the pasture with the pond.
Advantages
- Minimizes erosion of pond shorelines and dam faces.
- Reduces sediment deposition in pond.
- Extends useful life of the pond.
- Improves water quality for livestock and aquatic life.
- Improve wildlife habitat along the shoreline.
- Prevents cattle from walking out on the ice and falling into the pond.
- Eliminates livestock trails on the dam or in the emergency spillway that cause erosion.
- Minimizes transmission of diseases related to fecal deposition in the water.
Limitations
- Additional cost of fencing, including numerous corners due to irregular shaped fenced-out area.
- Additional cost of installing a waterer or limited access watering point.
Design Considerations
Testing the layout of a pond fence with electric fencing for a year or two before installing a permanent fence may reveal problem areas that can be addressed in the final fence installation. Eliminating or minimizing the number of sharp corners in the fence reduces potential erosion from livestock trails. Steep topography may add to the cost of the fence. A standard fence of four barbed wires with posts at 16- to 20-foot intervals is adequate in most situations.
The fence should provide an adequate buffer between the edge of the pond and the grazed area outside the fence. At least 30 feet of buffer is necessary to filter out sediment and nutrients. Grass cover is preferable to woody cover to maintain good water quality. Buffers are often used by ground-nesting birds; if they are too narrow, predators easily find the nests. Installing a gate in the fence allows flash grazing of pond buffers to maintain good grass cover and provides access for fire control equipment. Grazing should be done when pond banks are dry and stable.
A pipeline installed through a new or existing dam allows water to flow by gravity to a tank or waterer located below the dam. A limited access watering point allows livestock to drink directly from the pond but avoids many erosion and water quality issues with unrestricted access. Solar and animal activated pumps can be used to develop a pressurized watering system using pond water.
Pond seepage is best improved during pond construction. Even soils with adequate clay content can contain small clumps that prevent good sealing. Dispersants cause the clumps to dissolve and should be incorporated and the soil compacted into 6-inch layers during construction. When renovating an existing pond, the pond should be drained, scarified, sealed with a sealant, then compacted (Table 2). Sealing the pond after construction may not result in an acceptable improvement in sealing.
For more information on pond sealing:
Renovating Leaky Ponds. Stone N., Southern Regional Aquaculture Center, 1999
Ponds — Planning, Design, Construction. Deal C. et al. Agricultural Handbook 590, USDA 1997.
