Grand Canyon, Colorado River Flow Update
From Katrina Grantz, Hydraulic Engineer at Glen Canyon Dam:
Updated October 19, 2015
In October 2015, the release volume will be approximately 600 thousand acre-feet (kaf), with fluctuations anticipated between approximately 7,000 cfs and 13,000 cfs and consistent with the Glen Canyon Operating Criteria (Federal Register, Volume 62, No. 41, March 3, 1997).
The anticipated release volume for November is approximately 600 kaf with daily fluctuations between approximately 7,000 cfs and 13,000 cfs.
The expected release for December is 800 kaf with daily fluctuations between approximately 9,000 cfs and 17,000 cfs.
Fall 2015 High Flow Experiment Update
Due to resource concerns, the Department of Interior will not conduct a High Flow Experiment (HFE) at Glen Canyon Dam this fall. Although sediment conditions in the Canyon support a HFE, a concentrated grouping of green sunfish—invasive to the area—was recently discovered in a backwater slough downstream of Glen Canyon Dam. There is concern that an HFE could disperse this harmful nonnative downstream into the Colorado River, posing a threat to native endangered species in the Canyon. While response actions are underway to effectively address the green sunfish problem, the timeline for doing so is not conducive to conducting an HFE in November 2015.