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~ , Test Flow Scheduled for Spring 1996 By: Dave Wegner. Manager Glen Canyon Environmental Studies Bureau of Reclamation On November 30. 1995, the T/lI1lSition Wolk Group (TWG) for the Operation of Glen Canyon Dam Final Environmental Impact Statement (EIS) met in Phoenix to discuss the proposed Beach/Habifllt-Building Test Flow scheduled for late Malt:hlearIy April 1996. As a result of dis- cussions at that meeting, Reclamation directed the Glen Canyon Environmental Studies (GCES) office in Flagstaff to coordinate efforts for a Malt:hI April test of the beachlbabitat-building flow. This important step signifies the fust major endeavor to begin ecosystem/adaptive management below the dam. Importance of the Beach/Habitat-Building Test Flow Prior to constmction of Glen Canyon Dam, the Colorado was a sedimelt-laden, dynamic river. fluctuating according to the sea- sons, rainfall, and inflow from side canyons. The construction of Glen Canyon Dam altered thenaturaI dynamics of the Colomdo River. Lake Powell tmps water, sediment, and associ- ated nutrients that previously traveled down the river. Today, the ecological resources of the Grand Canyon depend on the water releases from the dam and variable sediment input from tributaries. A reduced sediment supply and regulated release of lake water oow support aquatic and terrestrial systems that did oot exist in the river corridor before the dam. The need for a conlroUed flood release was identified as the results of the GeES were reviewed by researchelS!scientists and the EIS team. As they began to understand the processes of the Colomdo River, it became apparent that in order for southwest- ern riverine/riparian ecosystems to maintain their vitality, peri- odic flow disturbances are necessary. Scientists determined that under any EIS alternative, the future of Grand Canyon sandbars depends on careful management of sand supplied from tribu- taries, daily water release patterns, and the long-tenn frequency and magnitude of flood releases from the dam. They concluded that Grand Canyon sandbaJs above the nonna! peak river stage would continue to erode, and backwater habitats would tend to fill with sediment without conlrolled flood releases. Therefore, beachlbabitat-building flows were incOl)lOllIted into the alternatives. as a common element, in order to restore a dynamic flow component to the river and to provide some of the processes of a naturaI system Upon reaching this conclusion, the GeES researchelS!scientists and the EIS team recommended that this hypothesis be tested prior to long-tenn implementation. The objective of this controlled release is to test the predicted results detailed in the fmal EIS. The beachlbabitat-building flow is descn"bed in the final EIS and represents the best opportunity to meet the release objectives at Glen Canyon Dam while supporting maintenance of the critical enviromnental processes and critical habitats in the Grand Canyon. The 1996 Annual Operating Plan, signed by Bruce Babbitt, SecretaIy of the Interior, contains the tenns and condi- tions of such releases. Scheduling the Experimental Flow The proposal for the controlled release was put forth initially in 1994 and again in 1995; but due to controversies surrounding legal issues, neither of these experimental flows could be con- ducted. In the summer of 1994, high runoff conditions into Lake Powell almost brought about an WlConlrolled high release. Since that time, agreement has been reached between the Department of the Interior and the Basin States (Arizona, California, COIOllldo, Nevada, New Mexico, Utah, Wyoming) regarding the long-tenn release ofbeachlbabitat-building flows, allowing a test of the flow to occur. Dr. Duncan Patten, GeES Senior Scientist, convened GCES researchelS and scientists to detennine options and opportunities for scheduling a conlrolled experimental release in 1996. Accomplishing the Test-Flow The road to the Malt:hI April 1996 test flow involves many stops along the way, including: Completion of a biological opinion on the test Completion ofNEPA compliance Consultation to deviate from Interim Operating Criteria Completion of the research and monitoring plan Concept document Individual proposals Peer reviews (minimum three per proposal) Permitting process (National Park Service, U.S. Fish and Wildlife Service, and Native American) Contractual process Coordination offlow releases with the Western Area Power Administration Coordination with the National Park Service on river permits Coordination of reporting requirements includingjUlI docu- mentation of results (continued on page 5) 4