November 2013 High-Flow Experiment
U.S. Geological Survey
The goal of the high-flow experiment is to move sand stored in the river channel and redeposit it to rebuild eroded sandbars and beaches downstream of the Paria River in Grand Canyon National Park.
This release follows the science-based Protocol for High-Flow Experimental Releases from Glen Canyon Dam established in May 2012 and is a component of the Department's compliance with the Grand Canyon Protection Act of 1992.
The Grand Canyon Protection Act mandates that Glen Canyon Dam be operated in a manner that protects, mitigates adverse impacts to, and improves the values for which Grand Canyon National Park and Glen Canyon National Recreation were established.
Previous experimental releases from Glen Canyon Dam have demonstrated that it is possible to rebuild beaches and sandbars in Grand Canyon via high flows.
Flow Information (download schedules by clicking on the graphics below)
At the start of the HFE on Monday, November 11, the flow will increase from 5,000 cfs by 4,000 cfs per hour for 4 hours until it reached the peak power plant release flow of approximately 22,200 cfs and then will increase by about 1,875 cfs per hour for 8 hours to the maximum release of approximately 34,100 cfs. The peak release will be held for 96 hours. Flows will begin ramp down on November 17 at a rate of 1,500 cfs per hour for 19 hours until a base release of 8,000 cfs is reached on November 18. The total duration of the experiment from beginning to end will be approximately five days.
Because of the distances downstream of the dam, increasing flows will reach downstream locations at different times. Flows will arrive at Phantom Ranch (River Mile 87) about 20 hours after release from Glen Canyon Dam, and almost 54 hours after release at Pearce Ferry (River Mile 279). Specific information about flow levels at varying locations within Grand Canyon will be posted before and during the high-flow experiment at Lees Ferry, Phantom Ranch and the Backcountry Information Center.
Current flow at Lees Ferry: http://waterdata.usgs.gov/usa/nwis/uv?09380000
Camp on Durable Surfaces
The area available for camping will be smaller at most sites, and river users and backpackers may have to set up tents closer to one another than they would during typical flows. It is especially important to follow Leave No Trace principles and travel and camp on durable surfaces during this high-flow experiment. Durable surfaces include bare sand above the high flow line, sites where people have previously camped and established trails.
Camps should not be established in the pre-dam old high-water zone, which is marked by mesquite, catclaw acacia, and netleaf hackberry on rounded sandy slopes or higher sand terraces.
View more chapters of the park's non-commercial river trip orientation video here or on YouTube
The high-flow protocol is a framework for using dam operations to release high flows following tributary deposits of new sand into the main channel of the Colorado River. It was developed by the Department of the Interior pursuant to the National Environmental Policy Act based on the best available scientific information developed through the
Glen Canyon Dam Adaptive Management Program and other sources of information.
The protocol builds on a wealth of scientific knowledge gained from more than 16 years of extensive scientific research, experimentation, and analysis, including analysis of a series of previous high-flow experimental releases in 1996, 2004, 2008 and 2012. The protocol is intended to provide additional data essential to inform and refine future management decisions for the management of the Colorado River through 2020.
Colorado River sandbars within the Grand Canyon provide habitat for wildlife, serve as camping beaches for recreationists, and supply sand needed to protect archaeological sites. High flows may also create backwater areas used by young native fishes, particularly the endangered humpback chub.
Did You Know?
From Yavapai Point on the South Rim of the Grand Canyon, the drop to the Colorado River below is 4,600 feet (1,400 m). The elevation at river level is 2,450 feet (750 m) above sea level. Without the Colorado River, a perennial river in a desert environment, the Grand Canyon would not exist.