# Grand Canyon, Colorado River Flows - June and July



## GCPBA (Oct 22, 2009)

This is a May 29, 2018, update from Paul Davidson at Glen Canyon Dam.

The release volume from Glen Canyon Dam for June, 2018, will be 760,000 acre-feet. Hourly releases during April, 2018, are anticipated to fluctuate between approximately 8,850 cfs in the nighttime and 16,450 cfs in the daytime. On weekend days in June, 2018, releases will be steady near 9,850 cfs. Additionally, in June, the LTEMP Bug Flow experimental fluctuation pattern will occur as described below.

The anticipated release volume for July, 2018, is 860,000 acre-feet. This will be confirmed in a subsequent notification toward the end of June. Please note, the monthly volumes for June and July are set, the Bug Flow experiment does not change monthly or weekly volumes.

(GCPBA note - Read about "Bug Flow" here: The Bugflow Experiment).

The Bug Flow experiment consists of steady weekend releases from Glen Canyon Dam and normal fluctuating releases during the weekdays. The steady weekend flows are expected to provide favorable conditions for insects to lay eggs along the Colorado River downstream of Glen Canyon Dam, while the minimum flows on weekdays are designed to be similar to flows on the weekends, thus preventing the eggs from drying out.

Performing this experiment will not affect the Monthly or Weekly planned release volumes. The affect will only be to the daily distribution volumes, and the peak and low daily flow rates.

Paul Davidson, Hydraulic Engineer, Glen Canyon Dam
Bureau of Reclamation 125 S. State St. Salt Lake City, UT 84138 Ph: 801-524-3642


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