Clarksville, TN – Conservation officials hope a sinkhole study will help determine their effect on groundwater. The study follows the Red River watershed along the Tennessee-Kentucky border. The U.S. Geological Survey, the Tennessee Department of Environment and Conservation and the Kentucky Department of Natural Resources have partnered in the effort. The Clarksville Leaf-Chronicle reports volunteers are needed to watch sinkholes and observe how quickly standing rainwater drains through them. The sinkhole study area runs just south of Russellville, Kentucky to just north of Springfield, Tennessee.