An assessment of water-borne and sediment-borne contaminant loading in the Conasuaga River: Implications for the Health of Aquatic Fauna
September 1998 - July 2000
- Cecil Jennings, Principal Investigator
- Marsha Black, Co-Principal Investigator
- USFWS Region 4
The Conasauga River, an important tributary to the Coosa River and Mobile Basin drainage systems in northwest Georgia, has recently come to the forefront in river preservation and restoration. The Conasauga River is one of the few remaining free-flowing rivers in the southeastern United States and the second largest river flowing into the northern Gulf of Mexico (RCDC 1996). The River begins in the Blue Ridge Mountains of the Cohutta Wilderness Area in Murray County, Georgia, and flows northwest from its headwaters into Polk County, Tennessee. It is later joined by the Jacks River about 10 miles before turning south back into Georgia where it forms the boundary between Whitfield and Murray Counties. The Conasauga River then flows about 100 miles south through Georgia before it confluences with the Coosawattee to form the Oostanaula River. The Conasauga River drainage forms a 500,000-acre watershed that mostly consists of forested and agricultural lands. The watershed lies within the Southern Ridge and Valley Provinces (SRVP) and the Southern Blue Ridge Province. It has a diverse aquatic fauna and provides important habitat for breeding and migrating land birds (RCDC 1996). The upper Conasauga River is considered to be a high quality watershed that serves as the major headwaters to the Coosa/Alabama River system (RCDC 1996). The headwaters of the Conasauga are located primarily within the Cherokee and Chattahootchee National Forests. A portion of the acreage (119,000 acres) of the watershed is protected within the boundaries of these national forests and 3,400 acres are situated within Fort Mountain State Park. Portions of the river runs through urban and industrialized areas, and the water quality in these reaches may reflect activities within that watershed. Degraded water quality may cause variable levels of stress to fishes, mussels, and other macroinvertebrates. The overall condition of the Conasauga River’s watershed and associated water quality parameters are unknown. The watershed was last scored in October 1997, and a variety of environmental factors (i.e, designated use attainment, fish consumption advisories, source water condition, contaminated sediments, ambient water quality-toxic ambient water quality-conventional, and wetland loss) were used to assess its conditions. The data reported for four out of the seven listed areas (fish consumption advisories, water quality and condition) were insufficient to score the watershed’s condition. The vulnerability of the watershed was assessed by scoring the following areas: wetland aquatic species at risk, toxic loads over permit limits, conventional loads over permits, urban runoff index, population change, and hydrologic modification from dams. The overall condition and vulnerability of the Conasauga River’s watershed could not be determined because of insufficient data (EPA 1998). Therefore, additional data are needed on aquatic species at risk, the effects of urban and agricultural runoff, and dam-related hydrologic modifications on the watershed and related water quality status. Point source and non-point source pollution are potential problems in the Conasauga River. Point source pollution may stem from municipal sewage discharges, industrial waste water, and accidental spills of hazardous materials. Non-point source pollution are contaminants that are generated over large areas such as runoff from croplands, mismanaged forests, paved surfaces, septic tanks, construction activities, and unpaved roads. Other harmful items to the river ecosystem are septic leachate, pesticides and fertilizers, and chemicals disposed of within the watershed. Sedimentation, considered a non-point source pollution, is the largest contributor to pollution in rivers (FISRWG 1998). Sediment is defined as particles of rock and soil that have been dislodged and transported by water (FISRWG 1998). Many aquatic species e.g., fishes, mussels, dragonflies) are threatened by degradation of water and habitat quality because of erosion from riparian habitat and resulting siltation and sedimentation. Also, clearcutting forests or removal of vegetation for powerline right-of-ways may cause spring run or seasonal streams to disappear before fish eggs hatch (Rhett Jackson, personal communication). Siltation from roads, land development, and agricultural activities can smother fish eggs and kill the insects that provide and important food source for other organisms. Also, timber sedimentation that results from improper construction or placement of logging roads and failure to revegetate skid and haul roads in a timely manner may threaten the survival of aquatic species and degrade water quality in the river ecosystem.