1995 EIS on Glen Canyon Dam Operations

The Glen Canyon Dam Final EIS analyzed baseline impacts of dam operations on downstream environmental and cultural resources from 1963 to 1990, and compared those baseline impacts to possible alternative operations of Glen Canyon Dam, including three alternatives that would provide steady flows from the dam and six alternatives that would provide various levels of fluctuating flows. The EIS team and the cooperating agencies identified a preferred alternative called: the Modified Low Fluctuating Flow Alternative. This EIS served as the culmination of the Glen Canyon Environmental Studies launched in the early 1980s to document the effects of Glen Canyon Dam on downstream resources, fulfilling one of the mandates of the Grand Canyon Protection Act of 1992.