Like geese migrating with the change of seasons, rivers ebb and flow across the months. The Green River is no different.
Late summer and fall bring just a trickle, while winter and spring bring periodic floods. These seasonal flow patterns orchestrate a cycle of life for the plants and animals residing in and around the Green, cuing fish to migrate and spawn and floodplain trees to drop their seeds. Even cave-dwelling species such as blind freshwater shrimp depend on the river’s natural pulse. This pulse changed in 1969 when the U.S. Army Corps of Engineers built a dam at its headwaters to control flooding and provide public recreation.
Almost thirty years later, The Nature Conservancy of Kentucky approached the Corps about operating the dam in ways which better mimic the river’s natural flow patterns in order to support native wildlife while meeting human needs. The Conservancy’s plea came after a scientific analysis revealed that while water releases from the Green River reservoir reasonably mimicked natural flows during much of the year, they were up to six times higher and significantly colder than historic natural flows during the fall, a critical spawning time for many fish and mussels.
The result has been a ground-breaking partnership. For more than a decade, the Conservancy and the Corps have worked together on a plan which includes releasing water later in the year to avoid the spawning period and more closely mimic natural flow and temperature patterns. Since then, there has been enhanced mussel reproduction below the dam without any loss of flood protection or recreation for human populations downstream.
Size: The Conservancy’s work focuses on the Green River’s 9,230 square-mile watershed.
Location: Central Kentucky, including the upper Green River watershed, major tributaries (Nolin, Rough, and Barren rivers and Pond Creek), wetlands complexes in the lower Green River, and Mammoth Cave National Park
What’s At Stake: The Green River gives life to more species of plants and animals than any other Ohio River tributary – especially in an unhindered 100-mile stretch that flows from the Green River Reservoir Dam and through Mammoth Cave National Park. This stretch harbors one of the most diverse assemblages of fish and freshwater mussels in the United States.
Threats: Altered hydrological flows from high level and low level dams; Water pollution
Milestones: For more than a decade, the Conservancy has worked with landowners, farmers, non-profit organizations and government agencies to achieve several milestones related to improving water quality and habitat within and around the Green River.
Partners: US Army Corps of Engineers, US Fish and Wildlife Service, USDA-Farm Services Agency, USDA-Natural Resources Conservation Service, US Geological Survey, National Park Service, Kentucky Department of Fish & Wildlife Resources, Kentucky Division of Conservation, Kentucky Division of Forestry, Kentucky Division of Water, Campbellsville University, Eastern Kentucky University, Tennessee Technical University, Western Kentucky University
Fish of the Green River
More than 150 fish species have been found in the Green, including the Teardrop darter.
Mussels are abundant in the Green River.
Learn how changing flows from dams can produce benefits for people and nature.
Learn how changes in flows from the Green River Dam have benefited people and nature.
A child's view of protecting our precious resources, like the Green River.