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World Water Day 2007 Home Water Scarcity A Honduras Dam One Size Doesn't Fit Saving the Yangtze IHA Software A New Era |
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Rivers nurture an overwhelming amount of the Earth's natural diversity — providing a source of nourishment, recreation, transportation and livelihood for hundreds of millions of people.
Yet two-thirds of the world’s rivers are impeded by dams. While these structures provide necessary services — such as drinking water and power generation — they jeopardize the health of the river systems. And that threatens the human and natural communities that depend on clean and abundant water.
Can Healthy Rivers Also Benefit People?
So The Nature Conservancy and the U.S. Army Corps of Engineers have formed a national partnership known as the Sustainable Rivers Project to promote healthy river systems that are also managed for benefits such as drinking water, power and flood control.
As America’s largest water manager and hydropower producer, the Corps is working with the Conservancy from Georgia to Oregon to reassess how its dams and river locks are managed and — in many cases — revising dam operations.
“By collaborating to ensure both healthy rivers and healthy human communities, The Nature Conservancy and the Corps are leaving a legacy for our children and examples of sustainable living for the rest of the world,” said Andy Warner, senior advisor for water management for The Nature Conservancy’s Sustainable Waters Program.
The Sustainable Rivers Project is currently working on 11 rivers with 26 dams that flow through 13 states. Additional dams will be added to the project in the future.
The Savannah Becomes a Model for Sustainable Water Management
In the southeastern United States, the Savannah River has become a model for sustainable water management.
Since 2004, the Conservancy has worked with the Army Corps to restore the freshwater, floodplain and estuarine habitats of the Savannah — by releasing water from the J. Strom Thurmond Dam to mimic seasonal floods that occurred before the dam was built.
Project staff members continue to assess the effects of these releases, including measuring the ratio of fresh and salt water in the estuary. The project is also monitoring the migration patterns of the endangered shortnose sturgeon, a fish that has been unable to pass through the New Savannah Bluff Lock and Dam to its historic spawning grounds. Scientists hope the increased flows from the releases help the fish bypass the structure.
“As a native species, sturgeon populations in the Savannah are a good indicator of the overall health of the river system,” said Amanda Meadows, Savannah River project director for The Nature Conservancy in Georgia.
Testing the Waters in Oregon
In addition to the Savannah River, other Conservancy freshwater projects are taking advantage of this national partnership to learn more about managing water systems for the benefit of people and nature.
In Oregon, the Army Corps and the Conservancy are working to determine environmental flow requirements for the Willamette River and its tributaries.
Currently, the Corps operates 13 dams in the Willamette basin, which control the volume and timing of water flowing in the river. These operations threaten critically important stream and floodplain habitats, which support a host of aquatic and terrestrial species and important runs of migratory salmon, trout and other fish.
As part of the Sustainable Rivers Project, 43 scientists recently came together to determine how much water was necessary to achieve more natural flows and to design recommendations for releases from the reservoir. The Corps and the Conservancy are preparing to test these recommendations later this year.
“The collaboration with the Corps is a unique opportunity to influence the future of water management in Oregon and throughout the United States and make a difference in the health of our freshwater systems,” said Leslie Bach, director of freshwater programs for The Nature Conservancy in Oregon.
Assuring Water for Texans and Texas Wildlife
And in Texas, scientists recently studies how releases at different levels affect the movement of sediments and aquatic life in the Big Cypress Bayou and Caddo Lake.
The opportunity arose when the Army Corps collaborated with the Northeast Texas Municipal Water District to systematically release water from the Lake O' the Pines Reservoir. The releases were designed to help restore and protect the rich ecosystem downstream of Lake O' the Pines while assuring adequate water for human needs.
“The coordination between engineers and ecologists being demonstrated in this release of water from Lake O’ the Pines represents a fundamental shift in how water is being managed, and a great deal of credit goes to the Army Corps of Engineers for moving this concept forward,” said Carter Smith, director of The Nature Conservancy in Texas.
Nature picture credits (top to bottom, left to right): Lynn McBride/TNC (Caddo Lake); Lynn McBride/TNC (Caddo Lake detail)
