The State of Natural and Cultural Resources in the Colorado River Ecosystem:
JUNE 30, 1999 DRAFT REPORT
Grand Canyon Monitoring and Research Center
Flagstaff, AZ 86001
Updated: 30 June 1999
Table of Contents
- Executive Summary
- Introduction and Administration
- Physical Resources and Processes: Climate, Hydrology, Sediment
- Water Quality: Lake Powell and the Colorado River Downstream
- Aquatic Biological Resources: Foodbase, Habitat, Native Fish, Non-native Fish
- Terrestrial Biological Resources: Vegetation, Habitat, Wildlife
- Endangered Species and Species of Concern
- Cultural Resources: Archeological Sites; TCP's; Ethonobiology; Havasupai, Hopi, Hualapai, Navajo, Southern Paiute and Zuni Tribes
- Socio-economic Resources: River Running, Angling, Hydropower Production
- Acknowledgements
- Bibliography
Socio-Economic Resources
-
- Recreation
- Power Production
Recreational Camping Beaches
In 1997, information on recreational resources was focused on qualitative assessments of recreational camping beaches. This study (O'Brien, et.al, 1999) consisted of repeat photography of selected camping beaches by volunteer boating guides. Report information indicates that 36 beaches were monitored during 1997. Of these, 25% (N=9), remained approximately the same throughout the year. About 63% (N=23) lost sand. By the end of 1997, 50% (N=18) were still larger than they were prior to the 1996 experimental flow and about 30% ( N=11) were about the same as in 1996 prior to the experimental flow or they were smaller.
Based on the beach observations, the report suggests that fluctuating flows were most influential for changes in beach morphology. High continuous flows were also identified as detrimental to maintaining greater beach areas.
Information provided by the NPS indicates the numbers of river rafters that visited the GCNP in 1997. The dam operations have the potential to affect these individuals perceptions of their river experience. Because there has been interested in the AMP to understand these possible changes in preferences and perceptions, the GCMRC currently is sponsoring a recreational study that assesses these attitudes. The project is on-going and results will be available in FY 2000. These results will be included in subsequent reports.
Fig. E1.1: Number of river runners through Grand Canyon, 1869-1998. Data courtesy of Grand Canyon National Park, updated 1 July 1998.
Day-use rafting from Glen Canyon Dam to Lees Ferry typically involves half-day trips. Nearly 40,000 visitors per year enjoy floating the last free-flowing section of Glen Canyon, a quiet-water river trip offered by Wilderness River Adventures from Page, Arizona. The GCMRC study that assesses visitor attitudes is also investigating day use rafters and fishermen. As noted above, the results of this study will be available in FY 2000.
Recent data on angling economics have yet to be compiled.
Hyperlink to Trout Section on angler use.
Power Production
Fig. E2.1: Mean hourly daily Glen Canyon Dam hydroelectric power production, Water Years 1997-1998. Data from the Bureau of Reclamation SCADA data; updated 17 November 1998.