Environmental Science Division (EVS)a Division of Argonne National Laboratory

Argonne contributes to development of a new long-term plan for managing operations at Glen Canyon Dam, Arizona

October 11, 2016

The Glen Canyon Dam Long-Term Experimental and Management Plan (LTEMP) Final Environmental Impact Statement (FEIS), developed by the Department of the Interior, with assistance from Argonne's EVS and Energy Systems divisions, was released on October 7, 2016. The effort, jointly led by the Interior's Bureau of Reclamation and National Park Service, identified a preferred alternative that would protect and improve conditions for downstream resources while limiting impacts on hydropower generation, in keeping with the Grand Canyon Protection Act. The alternative identifies a preferred dam release pattern and a plan to test, over the next 20 years, a series of flow and non-flow experiments that would address critical uncertainties regarding the effects of dam operations on downstream river conditions and the natural, cultural, and recreational resources dependent on them. These experiments will include high-flow releases to conserve and manage sediment; flows to improve conditions for trout, the endangered humpback chub, and other native fishes; and flows that might improve the aquatic food base that fish and wildlife depend on.

The Glen Canyon Dam, located in the Glen Canyon National Recreation Area and just upstream of Grand Canyon National Park in Arizona, stores and releases water to supply the municipal water needs of about 40 million people and the power needs of about 5.8 million retail customers in Arizona, Colorado, Nebraska, Nevada, New Mexico, Utah, and Wyoming. As stated in a press release issued by the Department of Interior, "the LTEMP will provide a framework for adaptively managing Glen Canyon Dam over the next 20 years with the goal of creating certainty and predictability for water and power users while protecting environmental and cultural resources in Grand Canyon National Park and the Colorado River ecosystem."

The LTEMP FEIS is available online at: http://ltempeis.anl.gov/documents/final-eis/