Locks and dams impact how people and wildlife live in and use the watershed.
Lock and Dam #6
Witness history as our partners dismantle the aging Lock #6.
The natural flow of a river resembles a healthy human heartbeat. Heavy rains send pulses of water downstream in spring, flushing out side channels and signaling fish to spawn. Dry stretches in summer allow seedlings to take root.
Dams and other man-made structures can change these rhythms. In fact, the beat of a heavily dammed river can look almost like a flatline. It causes natural systems to suffer.
In Kentucky, the Spring of 2017 marked a time when the Green River reclaimed its heartbeat. That is when trained workers from the U.S. Fish and Wildlife Service (USFWS) dismantled Lock 6, an aging steel structure that had not fulfilled its original purpose to control flooding and support navigation since 1951. In addition to involvement by the USFWS, removing Lock 6 resulted from a cooperative effort led by The Nature Conservancy and its partners, including the U.S. Army Corps of Engineers; the Kentucky Department of Fish & Wildlife Resources; the Kentucky Tourism, Arts and Heritage Cabinet; Mammoth Cave National Park; and Kentucky Waterways Alliance.
History of a Heartbeat
People have navigated Kentucky’s Green River for commerce since pioneer days. However, the Green’s natural pulse changed significantly in the 1930s with the advent of locks and dams built on the river and its tributaries—and eventually its headwaters—to aid in commercial navigation.
Eventually, the locks and dams caught the attention of The Nature Conservancy, leading the organization to approach the Army Corps of Engineers about operating these structures, and especially the Green River Dam, in ways that better mimic the river’s natural flow patterns to support native wildlife while meeting demands for clean water and recreation. The Conservancy’s request came after a scientific analysis revealed that, while water releases from the reservoir resembled natural flows during much of the year, they were up to six times higher and significantly colder than historic flows during the fall—a critical spawning time for many fish and mussels.
A partnership was born, and one of the first orders of business was to examine five old locks and dams on the Green River and one on the Barren River. Mike Hensley, the Conservancy’s Green River Project Director, describes the structures as, “old beasts—the oldest constructed in 1836—all showing signs of age and decline.” Hensley notes that removal of these dams is a win for both people and nature. In addition to the positive conservation outcomes, human safety is increased and river recreation improved, adding, “Removing these old, decaying structures, or carefully breaching them, will allow recreation enthusiasts to enjoy miles and miles of these rivers safely without the worry of being swept over a low-head dam.”
In March 2017, the Conservancy and its partners transformed planning into action with the permanent removal of Lock 6. This bold move was made possible by passage of the Water Infrastructure Improvements for the Nation (WIIN) Act of 2016, which included language de-authorizing four locks and dams on the Green River and one on the Barren River.
“The Conservancy played a major role in building support for the legislation among stakeholders, and Senator Mitch McConnell and Representative Brett Guthrie proved instrumental in getting the bill passed,” says David Phemister, the Conservancy’s State Director in Kentucky.
The legislation directs the U.S. Amy Corps of Engineers to transfer ownership of the locks and dams, and associated acreage, to various state and local entities, in several cases for the specific purpose of removing the structures from the river.
Phemister adds, “This is a huge step forward in our efforts to make the Green River healthier, safer and more valuable for a growing outdoor recreation economy.”
In addition to new outdoor recreation opportunities, removing Lock 6 and other aging structures will yield conservation benefits for the entire Green River system. Allowing for a more fully functional watershed benefits wildlife, including one of the most diverse assemblages of freshwater mussels in the world—species which serve as natural filters for these waters that provide drinking water to the local community.
Hensley says, “Removing this infrastructure from federal ownership presents an enormous opportunity to secure water supply, economic, recreation and conservation wins for the region. I look forward to what lies ahead."
Since this work began the Conservancy and its partners have the hard work pay off. While most of Dam #6 was removed at the outset, spring rains caused high-water conditions that, at the time, required the crew had to wait until later in the summer for lower water levels that would allow for foundation removal and re-contouring the river bottom. The Conservancy and partners also began preparing to remove Lock and Dam #5, about 14 miles downstream from the site of the former Dam #6. This process includes gathering data that will shape and inform a feasibility analysis and, eventually, the removal of another dam.