Glen Canyon Dam Adaptive Management Program Administrative History
This administrative history of the Grand Canyon Dam Adaptive Management Program (GCDAMP) includes government reports, oral history interviews and other relevant information about Colorado River law, environmental protection law, hydropower regulation, the Glen Canyon Environmental Studies that served as a precursor to GCDAMP, and the activities of the Adaptive Management Work Group, the Technical Work Group, and the U.S. Geological Survey’s Grand Canyon Monitoring and Research Center.
Filtering by
- Creators: Persons, William R.
- Creators: Pratson, Lincoln
Between 1999 and 2005, drought in the western United States led to a >44 m fall in the level of Lake Powell (Arizona-Utah), the nation's second-largest reservoir. River discharges to the reservoir were halved, yet the rivers still incised the tops of deltas left exposed along the rim of the reservoir by the lake-level fall. Erosion of the deltas enriched the rivers in sediment such that upon entering the reservoir they discharged plunging subaqueous gravity flows, one of which was imaged acoustically. Repeat bathymetric surveys of the reservoir show that the gravity flows overtopped rockfalls and formed small subaqueous fans, locally raising sediment accumulation rates 10–100-fold. The timing of deep-basin deposition differed regionally across the reservoir with respect to lake-level change. Total mass of sediment transferred from the lake perimeter to its bottom equates to ~22 yr of river input.
Summary:
Interview conducted by: Dr. Paul Hirt, Arizona State University and Jennifer Sweeney, Four East Historical Research, LLC. Glen Canyon Dam Adaptive Management Program Administrative History Project. Administered by Arizona State University Supported by a grant from the US Bureau of Reclamation.
Biography:
Aquatic biologist Bill Persons was involved in fisheries research during both phases of Glen Canyon Environmental Studies (GCES), the program that laid the groundwork for adaptive management in Grand Canyon. He has been an active participant in the Glen Canyon Dam Adaptive Management Program (GCDAMP) since it was implemented. Persons spent most of his professional life with Arizona Game and Fish Department (AZGFD), representing that agency on the GCDAMP Technical Work Group (TWG). He retired from AZGFD in 2009, but continued his involvement in fisheries research at Grand Canyon Monitoring and Research Center (GCMRC) for six years. Persons is currently a TWG alternate, representing recreational anglers for Trout Unlimited.