RRFW Riverwire - High Flow Experiment a GO!
October 23, 2018
On November 5-8, 2018, the Department of the Interior will conduct a high-flow experimental (HFE) release from Glen Canyon Dam. This HFE will include a peak magnitude release of approximately 38,100 cubic feet per second (cfs) for 60 hours (four days including ramping from baseflows to peak release) to move accumulated sediment downstream to help rebuild beaches and sandbars.
Schedule & Duration
Nov. 5 - 6:00 a.m. begin upramp to powerplant capacity (~23,100 cfs) [7 generation units]
Nov. 5 - 10:00 a.m. open bypass tubes, reach full bypass at 2:00 p.m.
Nov. 8 - 9:00 a.m. end of bypass
Nov. 8 - 3:00 p.m. end of High Flow experiment.
Total duration: 3 days & 10 hours; 2 ½ days at peak release
Ramp up: 4,000 cfs/hr from 6,500 - 23,100 cfs, then 3,750 cfs/hr to peak (38,100 cfs)
Ramp down: 1,875 cfs/hr from 38,100 – 23,100 cfs, then 2,500 cfs/hr to 9,000 cfs
High Flow Experiment Release Details
Maximum total release: 38,100 cfs
Powerplant capacity: 23,100 cfs
River outlet tubes: 15,000 cfs
Hydropower generation units available: 7 (one unit off-line for replacement)
River outlet tubes: 4
Releases and Lake Elevation
Releases will range from 6,500 - 9,000 cfs prior to and after the HFE
Lake elevation is projected to decrease by approximately 2 ½ feet during the 5-day experiment.
The "high flow" is close to the lowest pre-dam seasonal high flows seen yearly before the Glen Canyon Dam bypass closed in 1963.
This release courtesy Bureau of Reclamation
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