Water: Nonpoint Source Success Stories
Georgia: Restoration of a Riparian Forest - An Agricultural Water Quality Improvement Project
Intensively farmed areas can maintain good water quality if riparian forests are left in place along the streams draining agricultural areas. Such forested areas are usually wetlands; they filter water and prevent excess chemicals, dissolved solids, nutrients, and sediments from reaching downstream waters. Therefore, the reestablishment of riparian forests that have been cut or drained can also be expected to contribute to water quality improvements.
Until now, the benefits of restored riparian forests on water quality have not been demonstrated or evaluated in the Southeastern Coastal Plain. This 319 project a riparian restoration in the Sewanee River Basin near Tifton, Georgia, became the first to focus on the efficiency of the restored forested wetland to store and remove nutrients.
The project was designed to reestablish a riparian forest to ameliorate the water quality impacts of applying liquid manure to cropland; that is, to determine whether a restored riparian forest trees, shrubs, and native grasses would improve the quality of runoff leaving the manure application site and moving through the riparian area to the stream. It was conducted in conjunction with an agricultural project at the University of Georgia's Coastal Plain Experiment Station near Tifton.
The project demonstrated that riparian forested wetlands can be restored to help prevent nonpoint source pollution from manure application sites.
The USDA Agricultural Research Service participated in the section 319 project to restore a streamside riparian forest receiving runoff from the USDA-funded liquid manure application and forage crop production site. The Tifton project sought to demonstrate the conservation and water quality effects of using minimum plowing and liquid manure to grow forage crops. It was funded by the U.S. Department of Agriculture's Low Input/Sustainable Agriculture Program.
Obstacles and successes
Riparian vegetation was successfully restored in the project area, but not before several obstacles had been overcome, for example, knowing which species to plant. Yellow poplars were not a good choice for wet conditions; black gum and green ash were effective substitutes. Within two months it was apparent that there would be low survivorship among the poplars, since they were not locally produced seedlings and did not thrive in wet, saturated soils. Black gum and green ash were substituted since it was thought they would tolerate wet conditions.
Project workers evaluated the effects of the riparian restoration by measuring changes in surface and subsurface water quality indicators in the field where manure was applied and again after the runoff had moved through the restored riparian area toward the stream. Results of the monitoring demonstrated that the restored riparian area removed nitrogen, phosphorus, and sediment in the first two years of the project. Nitrate levels leaving the area in shallow groundwater were higher than in mature riparian forest sites.
The project demonstrated that riparian forested wetlands can be restored to help prevent nonpoint source pollution from manure application sites. Information gleaned from this project, and others, has been incorporated in an interim USDA Natural Resources Conservation Service and U.S. Forest Service specification for Riparian Forest Buffer Systems. The guide recommends a three-zone buffer system in riparian areas.
|CONTACT: Frank Carubba
Georgia Department of Natural Resources
Evaluating Best Management Practices -
A Farm Demonstration Project in Rayle, Georgia
Traditional methods of allowing livestock free access to streams and pastures must change as modern farming methods intersect with environmental concerns. With this commitment, the Georgia Resource Conservation and Development Council, Inc., several conservation districts, federal agencies, and the University of Georgia arranged a farm demonstration to teach area cattlemen that new practices to keep livestock out of streams could be cost-effective and practical. After selecting a dairy farm, the partners helped install and monitor the following practices: proper grazing management, nutrient management, animal waste management systems (including holding pond, solid separator), loafing area, geotextile walkway, and livestock exclusion. The dairy farm is located within a 385-acre watershed in northeastern Georgia's Savannah River Basin near Rayle. In fact, it sits on an unnamed tributary that flows into a pond next to the most heavily used section of the dairy. The unnamed tributary continues through a wetlands (actually, another pond that had been breached) and flows into the Broad River.
The 793,000 acres of agriculture land within the watershed contain the following animals: 22,000 dairy cows, 185,000 beef cows, 95,000 swine, and about 22 million poultry (layers and broilers). These animals potentially contribute to the nonpoint source pollution problems in the watershed and river basin. Direct access of livestock to streams and runoff from loafing areas have degraded the watershed and impaired water quality, wildlife habitat, and recreational activities.
The project managers planned an extensive water quality monitoring program to demonstrate that the recommended best management practices were cost-effective and practical. Water quality measurements included biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), fecal coliform, fecal streptococci, nitrate, ammonia, and orthophosphate. Additional in situ parameters monitored by an automated sampler included pH, temperature, conductivity, ammonia plus ammonium, turbidity, depth, and dissolved oxygen.
Comparing the results from post-BMP and pre-BMP monitoring show a marked improvement in water quality. Statistical analyses have indicated significant decreases (p 0.05) in ammonia, orthophosphate, TSS, COD, BOD, and fecal streptococci. Extensive water quality monitoring has quantitatively demonstrated that the recommended BMPs are both cost-effective and practical.
|CONTACT: Frank Carubba
Georgia Department of Natural Resources