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The Department of the Interior is currently conducting an experiment to inform managers about the effectiveness of using high flows from Glen Canyon Dam to improve natural, recreational, and cultural resources in Grand Canyon National Park. The approved experiment consists of two types of experimental flows to be implemented beginning in 2008 and concluding in 2012:
1) An experimental high flow test of approximately 41,500 cfs for a maximum duration of 60 hours March 5 - 7, 2008, and
2) Steady flows in September and October of each year, 2008 through 2012.
NPS Comparative Photos
(1.35MB PDF File)
Photos were taken during the 2008 High Flow Experiment at 41,000cfs, and following downramp to lower steady flows.
(928kb PDF File)
Photos taken by NPS staff in March and April, 2008, are compared to beach photos taken between 1996 and 2007 to show affects of the High Flow Experiement.
The overall concept of the experiment is to determine the effectiveness of sandbar building and backwater formation using a high flow test during highly enriched sediment conditions, and the subsequent impact on humpback chub in those backwaters during fluctuating flows in the spring and summer and steady flows in the fall. The timing of fall steady flows follows young-of-year emergence of humpback chub from the Little Colorado River into the mainstem. Intense monitoring and research conducted throughout this period will identify resultant effects on these geomorphic features and aquatic species. The need for additional high flows during this experiment will be determined though a cooperative decision-making process with the Adaptive Management Work Group.
The U.S. Geological Survey’s Grand Canyon Monitoring and Research Center worked collaboratively with the Department of the Interior’s Bureau of Reclamation, National Park Service, and U.S. Fish and Wildlife Service to prepare for and to conduct the 2008 high-flow release. These agencies as well as the Arizona Game and Fish Department, Northern Arizona University, Utah State University, and other cooperators are conducting a range of research activities.
Scientists, through this high flow experiment, seek to use high flows to rebuild Grand Canyon beaches by moving sediment accumulated from the riverbed onto sandbars. The experimental studies associated with the proposed high flow event are designed to build upon existing scientific knowledge about how high flows from the dam effect the range of resources, including sandbars and humpback chub habitat, rainbow trout movement, the aquatic food base, riparian vegetation habitat, archeological sites, and water movement.
In addition to these studies, the National Park Service will conduct a series of environmental assessments taking place following the high-flow event, which include changes in campsite availability and associated visitor experience, undesired potential for recruitment of invasive plant species, and assisting various American Indian Tribes in monitoring culturally significant resources.
(65kb PDF File)
Contacts:
Visit the Grand Canyon Monitoring and Research Center's 2008 High-Flow Experiment web site:
http://www.gcmrc.gov/research/high_flow/2008/
Grand Canyon National Park’s River Permits Office: 1-800-959-9164
Visit Grand Canyon National Park's permit page:
http://www.nps.gov/grca/planyourvisit/permits.htm
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