7387 - Laserfiche WebLink

Home Browse Search

I I, I I I I I I I I I I I I I I I I I GLEN CANYON ENVIRONMENTAL STUDIES FINAL REPORT SUMMARY AND PRINCIPAL CONCLUSIONS This report was prepared by individuals representing the following: Bureau of Reclamation Geological Survey Arizona Game and Fish National Park Service Fish and wildlife Service Private Consultants INTRODUCTION INTER-AGENCY STUDY ASSESSED IMPACTS ,OF GLEN CANYON DAM OPERATIONS. This report presents the findings of the Glen Canyon Environmental Studies (GCES). In December of 1982, the Secretary of the Interior directed the Bureau of Reclamation (BOR) to initiate a multi-agency study to address the concerns of the public and other federal and state agencies about possible negative effects of the operations of Glen Canyon Dam on downstream environmental and recreational resources. This studv was not intended nor desiqned to lead directlv to chanqes in dam operations. Any decision to make operational changes would require feasibility studies and National Environmental Policy Act (NEPA) compliance activities to assess the impact of those changes on the primary mandate of the Colorado River Storage Project (water storage and delivery), power generation, and economic considerations, as well as on the environment and recreation. OBJECTIVES The GCES study goals were, first, to investigate the impact of several aspects of current dam operations on the existing environmental and recreational resources in the Glen Canyon National Recreation Area and Grand Canyon National Park--specifically the effect of very high, very low, and strongly fluctuating releases from the dam. Second, if adverse impacts to downstream resources were found, the study was to determine whether modifications made to dam operations, within the constraints of Colorado River Storage Project water delivery requirements, could reduce those impacts. These modifications were to be based on environmental needs and did not include a full economic, cost-benefit analysis. To accomplish the study goals, over 30 technical studies in the fields of biology, recreation, 5