Water: Nonpoint Source Success Stories
Lower Powell River -
Riparian Restoration and Karst Conservation Program
During 1992, the Virginia Department of Conservation and Recreation, Division of Soil and Water Conservation, awarded the Nature Conservancy a nonpoint source pollution implementation grant for the Lower Powell River Riparian Restoration and Karst Conservation Program in Lee County, Virginia.
This program was designed specifically to protect priority riparian and karst areas in the Lower Powell River Hydrologic Unit. The Department of Conservation and Recreation ranks this area as a priority because it is sensitive to nonpoint source pollution and host to an unusually rich aquatic and cave biodiversity.
As many as 37 species of mussels live in the Powell River, including six species that the U.S. Fish & Wildlife Service lists as endangered. In addition, 12 of the top 24 cave communities in the Commonwealth are found in this hydrologic unit, which is also the most significant karst area in the state. The project included an extensive information and education program to publicize the region's biological significance and the importance of conserving land, water, and karst/groundwater resources.
Objectives and methods
Each restoration activity complied with the best management practice protocols specified by the Department of Conservation and Recreation and the USDA Natural Resources Conservation Service (NRCS) and was evaluated using chemical analysis and bioassessments of macroinvertebrates. In addition, the project included a hydrogeologic investigation of the Cedars karst region (Central Lee County Karst Area) to ensure that major groundwater basins were included in the karst conservation.
Eight restoration projects were completed from October 1992 through December 1994. These projects included four riparian restoration projects at ecologically significant mussel concentration sites on the Powell River and four karst conservation projects at critical cave and karst recharge sites within the Central Lee County Karst Area.
Each project was designed and implemented with technical assistance from the NRCS. The Daniel Boone Soil and Water Conservation District and the U.S. Fish and Wildlife Service also provided financial support for additional best management practices (BMPs) at many of the restoration sites. Other partners also contributed to various aspects of the project: for example, the Virginia Department of Forestry, the Virginia Cave Board, the U.S. Army Corps of Engineers, and the Cooperative Extension Service.
Highlights of the restoration
The project protected 13,500 feet of riparian habitat along the Powell River and other waterways; 22 species of mussels, including three endangered species; the entrance of Gollahon Cave Number 1, a habitat for seven globally rare cave-adapted species including the federally endangered Lee County Cave Isopod; and two sinking streams and a sinkhole dump site in the Cedars karst recharge area.
The array of management strategies used to achieve these protections included denying stream access to 250 head of cattle grazing upstream of four significant mussel concentration sites; fencing and bank stabilizing activities at the cave entrance; the development of alternative watering sites for livestock at five project sites (using two water wells, 5,000 feet of pipeline, and seven water troughs serving 12 fields); stream and sinkhole cleanups; and several innovative practices including the "cow-powered" Rife pasture pump, freeze-proof troughs, division fencing for rotational grazing, solar fence chargers, and a stream crossing reinforced with geotextile filter cloth.
Reduced concentrations of herbicides/pesticides
Restoration projects, where feasible, were paired with monitoring stations to evaluate changes in water quality and macroinvertebrate communities before and after restoration. Parameters for water quality measurements were pH, dissolved oxygen, nitrates and nitrites, stream flow, conductivity, total fecal coliforms, total dissolved solids, and total suspended solids. The project used EPA Rapid Bioassessment Protocol III to evaluate macroinvertebrate communities.
Results of chemical water quality monitoring of data collected over a 12-month period tended to follow predictable curves according to precipitation event intensity and duration. All data collected and analyzed for herbicide and pesticides revealed concentrations below detection limits.
|A heightened conservation ethic will be among the enduring benefits of this project.
Continued monitoring on the Lonesome Creek watershed may better determine effectiveness of livestock crossings and other best management practices since the project there addressed a much smaller drainage. Flows from springs or open cave systems appear to follow surface stream curves, indicating that flow regimes are subject to stormwater inputs.
Biological assessments using EPA Rapid Bioassessment Protocol III were inconclusive. Factors contributing to this result include the limited time allotted to the study, the variety of sites, and difficulty at some locations in determining valid control sampling locations. Despite these challenges, several sites did improve following BMP installations and visual indications are that habitat improvements (such as plant recovery on banks and sediment reductions) will prove beneficial to macroinvertebrate populations and species diversity. In each case, vegetation improved and bank instability was reduced by removing livestock from sensitive rivers, streams, sinking streams, and cave entrances.
The Lower Powell River Riparian Restoration and Karst Conservation Program projects were significant not only for their direct conservation benefits, but also because they will serve as permanent demonstrations of ways to protect the unique resources of Lee County, Virginia. Each one applied a new conservation technique or innovative practice to this ecologically important region of southwest Virginia. Thus, a heightened conservation ethic will be among the enduring benefits of this project.
|CONTACTS: Stu Wilson
Department of Conservation and Recreation
Alternative Watering Systems for Livestock -
The Middle Fork Holston River Builds on Success
The New River Highlands Resource Conservation and Development Council, sponsor of the Middle Fork Holston River Project (see Success Stories, 1994), has begun a new section 319 project in the watershed.
The new project (the fourth section 319 project in the Middle Fork Holston watershed since 1990) was launched in April 1994. Entitled "Using TMDL Study to Plan and Model BMP Implementation in the Middle Fork Holston," this project has focused on the implementation of best management practices (BMPs) in the Greenway Creek and Chestnut Ridge, two subwatersheds in Washington County.
The Middle Fork Holston watershed includes 153,437 acres covering a 38-mile stretch in Smyth and Washington Counties in southwest Virginia. The towns of Abingdon, Chilhowie, and Marion are located in the watershed. The subwatersheds of Greenway Creek and Chestnut Ridge are located in the southern portion of the Middle Fork Holston watershed in Washington County.
Project managers selected the sites by identifying the most critical treatment sites for water quality benefits based on the total maximum daily load (TMDL) methodology developed in 1991 with 319 funding. Area farmers then installed various BMPs, including alternate watering systems for cattle (beef and dairies), streambank fencing, and pasture management improvements.
Project managers used the AGNPS model to quantify pollutant loading reductions for the various practices based on site-specific conditions (e.g., soil type, slope, proximity to stream). Then they used a computer-based geographic information system (GIS) named VirGIS with the AGNPS model to rank land tracts in the subwatersheds based on their potential for contributing nutrient (nitrogen and phosphorus) and sediment loadings.
In all, 18 farmers participated in the project, each one implementing an alternative watering system for cattle. Five cooperators used solar powered pumps to operate their watering systems; two connected their systems to public water; and the remainder used electric power. The water sources varied from spring development to water intakes in streams and farm ponds.
In conjunction with the watering systems, the farmers also installed 8,000 feet of fencing to protect streambanks, and three of the farmers implemented pasture management BMPs. The Greenway Creek and Chestnut Ridge subwatersheds total 6,133 acres. BMPs were installed on 1,996 acres. The total length of streambank in the two subwatersheds is 24.88 miles.
Based on the expected performance of these BMPs, VirGIS and the AGNPS model predicted that 4,880 tons of sediment, 24,948 pounds of nitrogen, and 3,330 pounds of phosphorus would be removed from the nonpoint source loading to Greenway Creek. Reductions to Chestnut Ridge included 3,788 tons of sediment, 22,809 pounds of nitrogen, and 3,396 pounds of phosphorus. The estimated reductions in sediment, nitrogen, and phosphorus loadings are listed in Table 1 are based on the period of May 1994 through June 1996.
|Table 1. - Nutrient loadings (May 1994 - June 1996)|
|Sediment||27,730 tons||22,850 tons||4,880 tons|
|Nitrogen||160,592 lbs||135,644 lbs||24,948 lbs|
|Phosphorus||31,790 lbs||28,460 lbs||3,330 lbs|
|Sediment||16,474 tons||12,787 tons||3,788 tons|
|Nitrogen||93,486 lbs||70,677 lbs||22,809 lbs|
|Phosphorus||17,889 lbs||14,493 lbs||3,396 lbs|
The Tennessee Valley Authority (TVA) has used the Index of Biotic Integrity (IBI) for fish community structure and conducted benthic surveys to assess water quality conditions in the Middle Fork Holston watershed on an annual basis since 1988. The 1994 to 1996 IBI scores showed no improvement in the upper Greenway Creek subwatershed, despite the predicted nonpoint source loading reductions. IBI scores remained in the poor to fair range but did improve over 1991 baseline conditions, and benthic invertebrate sampling using the family-level Ephemeroptera, Plecoptera, and Tricoptera (EPT) index indicated water quality improvements from 1994 to 1996. Scores improved from "poor to fair" to the "good" range.
For the Chestnut Ridge subwatershed, the IBI scores and EPT scores did not improve for the 1994-1996 period, even though the project resulted in a substantial reduction in the sediment, nitrogen, and phosphorus loadings there. EPT scores would be expected to respond faster than IBI scores to water quality improvements. A lack of increase in the biological indicator scores indicates a system lag time between the actual BMP implementation and habitat improvements that generally are reflected in positive changes in the biological community structures, providing water quality is adequate. The biological monitoring will continue in 1997.
Keys to success
Projects in the Middle Fork Holston have been successful so much that other watershed groups across the state have visited the project area. The New River Highlands Resource and Conservation District attributes its success to several factors:
- project marketing by a conservation specialist who makes numerous one-on-one contacts with landowners;
- strong local support spearheaded by a watershed committee;
- successive 319 projects, each building on the other;
- adequate sources of funding beyond 319 from TVA and NRCS help support the BMP implementations; and
- a preexisting monitoring network in the watershed.
|CONTACTS: Stu Wilson
Virginia Department of Conservation and Recreation