Reclamation Releases Environmental Assessment for Public Review and Comment on an Experimental Protocol for High-Flow Releases from Glen Canyon Dam

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Date: January 20, 2011
Contact: Lisa Iams/USBR, 801-534-3673
Contact: Beverley Heffernan/USBR, 801-524-3712


The Bureau of Reclamation has released a Draft Environmental Assessment for the Development and Implementation of a Protocol for High-Flow Experimental Releases from Glen Canyon Dam, from 2011 through 2020 for a 30-day public review and comment period.

The EA analyzes the effects of implementing a protocol to conduct multiple high-flow experiments from the dam between 2011 and 2020 to better determine whether and how sand conservation can be improved in the Colorado River corridor downstream of the dam. The protocol will provide an adaptive management framework to learn how to better conserve the limited sand supply to the Colorado River below the dam, while ensuring that no significant impacts occur to other downstream resources affected by the high releases.

During a high flow experiment, the high volume of water released from the dam suspends sand stored in the river channel deposited by tributaries. A portion of that sand is re-deposited in the downstream river reaches as sandbars and beaches while another portion is transported downstream by river flows. These sand bars and beaches, and the associated near-shore habitats, are important components of the Colorado River ecosystem in addition to providing camping opportunities for river runners and hikers along the Colorado River within Grand Canyon National Park.

The Department of the Interior initiated development and implementation of the protocol as part of the ongoing Glen Canyon Dam Adaptive Management Program, to build on the knowledge gained from the previous high-flow experiments conducted in 1996, 2004, and 2008, and to comply with requirements and obligations established by the Grand Canyon Protection Act of 1992.

The draft EA was prepared in accordance with the National Environmental Policy Act and is available at

A printed copy of the report is available at the Bureau of Reclamation Upper Colorado Regional Office, 125 South State Street, room 7218, Salt Lake City, Utah 84138.

Written comments may be provided to Reclamation through February 14, 2011 to the address above or via e-mail at e-mail us . For more information, or to request a printed or CD-ROM copy of the EA, please contact Dennis Kubly at (801) 524-3715.




Reclamation is the largest wholesale water supplier and the second largest producer of hydroelectric power in the United States, with operations and facilities in the 17 Western States.Its facilities also provide substantial flood control, recreation, and fish and wildlife benefits.Visit our website at

Last updated: February 24, 2015

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