Riparian Area Management Techniques

By David Redhage
Natural Resources Economist, The Kerr Center for Sustainable Agriculture

Introduction
Riparian area management and rotational grazing systems work together to protect and enhance water quality, soil, and wildlife habitat. The Kerr Center Stewardship Ranch has developed several working demonstrations to show producers how these techniques work in the field.

Riparian Areas – An Important Natural Resource
A riparian area is the vegetated area adjacent to a stream or any other water body. Riparian areas are threatened primarily due to their location and attractiveness. Riparian bottomland forests are often prime farmland that has been cleared for crop land or pasture while some riparian areas are considered prime real estate by developers. Channelization of streams has also reduced the effectiveness of many riparian areas.

What are the benefits of a riparian area? Riparian areas help reduce floods, stabilize streambanks, control and reduce the effects of nonpoint-source pollution, and provide food and shelter for wildlife. Nonpoint-source pollution can include pesticides, fertilizers, and sediment from the surrounding watershed.

Fencing Riparian Areas
The Kerr Center is developing several riparian area demonstrations on its Stewardship Ranch. Cattle have been fenced out of some riparian areas for eight years and others for one to three years. Several riparian areas will not be fenced. One controversy surrounding riparian area management is whether or not to exclude livestock. The Kerr Center Ranch practices rotational grazing as opposed to continuous grazing. By allowing access to some riparian areas and excluding livestock from others, visitors will have a chance to judge for themselves how fencing livestock out of the riparian area compares to riparian areas located in rotationally grazed pastures. Trees are being planted in fenced areas to enhance the wildlife habitat benefits. Photo monitoring is being used to record changes in the riparian areas. Photo monitoring is an excellent way to monitor gradual changes in habitat that occur over long periods of time.

Before fencing a riparian area, several things must be considered. Often the riparian stream is the water source for livestock. If livestock production is the goal, then developing other watering points is important.

To photo monitor a practice, select an area from which the photo will be taken, identify key features such as a utility pole, tree, or other landmark, and record the spot in a file. Return at the same time each year to take a photograph. It would probably be better to monitor on a quarterly basis, so changes can be documented in each season of the year.

Limited-Access Watering
At the Kerr Center Stewardship Ranch, several ponds have been constructed outside of the riparian areas to provide water for the livestock. Developing these water points has had the added benefits of allowing us to cross-fence more effectively, intensify grazing, and better utilize the pastures.

The new ponds have been fenced so cattle have restricted access. A floating fence and rock ramps have bee installed to allow cattle access to the water, yet keep them from wading into the pond. The ramps help prevent soil erosion, extend the life of the pond, improve water quality and enhance the wildlife benefits of the pond.

A floating fence needs to be located where the water is at least 5 feet deep, 20 feet from the shore. A floating fence may be constructed from 2" schedule 40 PVC pipe to form an access lane for cattle. If muddy conditions are possible at the watering point, gravel and possibly an underlying layer of geotextile should be installed on the ramp.

Stream Crossing Points
Stream crossing points are an important consideration for both livestock and machinery. Often pastureland is dissected by a stream and simply fencing the stream out can concentrate livestock at a single crossing point. Stabilizing crossing points can help eliminate some of the problems associated with the increased traffic. A stabilized crossing point has a gradual sloping bank covered with a material that resists the impact of cattle and machinery. This type of crossing helps reduce water pollution by stopping soil erosion, thereby reducing nutrients and sediment from entering the waterway. Several crossing points have been installed on the stewardship ranch for livestock and equipment. The NRCS provided the design which called for excavating a trench one foot deep across the bed of the water-way. The bottom was covered with 3 inches of sand, 1 piece of 8mm geotextile, and 10 inches of gravel. The idea is to provide a firm crossing point that is stable enough to withstand the force of water flowing over the top without eroding the crossing. Installation costs were as follows:

Benefits of Protecting Riparian Areas
One of the most important aspects of a riparian area is the benefit to wildlife. Not only do riparian areas provide food and shelter, but they act as travel corridors between increasingly segmented habitats. The main threat to wildlife today is habitat loss. Riparian areas provide two major habitats: aquatic and terrestrial. The aquatic habitat consists of perennial streams and wet-lands. Vegetation in the riparian area affects the water temperature which influences fish. Vegetation is also a source of food for invertebrates which are the basis of the food chain. If protecting the fishery is important, maintaining the vegetation within twenty-five feet of the shoreline is important. Providing habitat for land-based wildlife is another important function of a riparian area. Generally, the riparian area contains a diversity of structure which increases the number and kind of animal species present. Diversity of structure refers to diversity in the type and age of vegetation.

One of the most frequently asked questions seem to be: "How wide should a riparian area be, and what should be planted"? Unfortunately, the answer is not that easy. It all depends on what your goals are, how the adjacent land is being used, and the slope of the land. The width of a riparian area is measured from the top of the stream bank, back. If the adjacent land is in row crops, a riparian buffer may be needed to filter out fertilizers, herbicides and sediment before runoff enters the stream. A buffer strip in this case may consist of maintaining a grass strip between the field and stream. If the goal is diverse wildlife habitat, the width of the riparian area is influenced by the wildlife you hope to attract and what type of vegetation you will plant. Often planting trees and shrubs is not necessary. If native tree and shrubs exist in the watershed, eventually they will be found in the riparian area.

Agriculture is being looked at increasingly as a source of non-point source pollution, and riparian areas can help buffer and reduce the effects of non-point source pollution. Protecting riparian areas demonstrates to an increasingly urbanized population that agriculture is concerned about the environment and is doing its part to protect the environment while producing the food society needs.

Reference: Oklahoma Cooperative Extension Service, Oklahoma State University. Riparian Area Management Handbook. Publication E-952. 1998.

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