The Colorado River ecosystem has been impacted for decades by the existence of Glen Canyon Dam, which has degraded the river’s beaches, and altered flood regimes, stream flows, and water temperature. The Colorado’s native fish have suffered from these changes, coupled with predation by, and competition with, non-native fish species including trout, catfish, and striped bass.
Crowding, overuse, and lost opportunities to experience wilderness are also important issues on the Colorado River. The annual number of river visitors alone has gone from 2100 in 1967 to nearly 22,000 currently. Most of the Colorado River was recommended for wilderness designation by 1980, when the Management Plan quoted below came out:
“ The Grand Canyon provides an exceptional setting for an experience of wilderness… the roar of each rapid, the sight of the clear night sky, and the songs of canyon wrens along the shore are all part of the Grand Canyon wilderness experience which this plan seeks to preserve….”
Unfortunately, much of the wilderness recommended by Grand Canyon National Park has not yet been federally designated, and the river has yet to be managed as wilderness. Contrary to the Wilderness Act, Grand Canyon’s new plan for the Colorado River continues to allow motorboats. In addition, the 2006 Colorado River Management Plan:
This is of great concern, because a recent United States Geological Survey report, The State of the Colorado River Ecosystem in Grand Canyon (104 KB pdf), revealed that the river’s beaches are rapidly dwindling, native fish are declining, and archeological sites are threatened. This is largely due to the operations of Glen Canyon dam, and made worse by overuse on the river. In 2005, the Sierra Club and others submitted strong comments (316 KB pdf) in favor of a more protective Colorado River Management Plan. In 2006, along with several other groups, the Sierra Club won a favorable settlement (44 KB pdf) in response to our lawsuit (100 Kb pdf) to persuade the Department of Interior and Bureau of Reclamation to operate the dam in a way that will restore the river system.