The 2018 Fall HFE
From Glen Canyon Dam AMP
| High Flow Experiment- 2018 | |
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Contents
2018 High Flow Experiment Snapshot
Sediment Conditions
Fall Accounting Period
- Paria input (Jul 1 - Nov 4): 753,000
- Accumulated in Upper Marble Canyon (Jul 1 - Oct 1, lower bound) = 240,000
- Accumulated in Lower Marble Canyon (Jul 1 - Oct 1, lower bound) = -68,000
- Available for HFE: 240,000 + -68,000 = 172,000
- Paria input (Nov 5 - 10): 1,119
- Evacuated from Upper Marble Canyon (Nov 5 - 10, lower bound) = -360,000
- Evacuated from Lower Marble Canyon (Nov 5 - 10, lower bound) = -160,000
- Left over in Marble Canyon after HFE (Nov 5 - 10): 172,000 + 1,119 - 360,000 - 160,000 = -346,881
- Paria input (Nov 11 to Apr 1): 366,588
- Accumulated in Upper Marble Canyon (Dec 1 to Jun 30, lower bound) = -120,000
- Accumulated in Lower Marble Canyon (Dec 1 to Jun 30, lower bound) = 120,000
- Available for spring HFE: -120,000 + 120,000 = 0
HFE Details
Schedule & Duration
- Nov. 5 - 6:00 a.m. begin upramp to powerplant capacity (~23,100 cfs) [7 generation units]
- Nov. 5 - 11:00 a.m. open bypass tubes, reach full bypass at 2:00 p.m. (38,100 cfs)
- 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 (60 hours)
Ramp Rates
- 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
- 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 7 inches during the 3-day experiment
- Estimated acre feet of water bypassed during HFE: 81 kaf
Costs
- Estimated costs to hydropower: $923,963
- Actual costs to hydropower: $1,300,000
- Direct expenses for removal of concession assets: TBD
SUPPORTING DOCUMENTS
- Financial Analysis of Experimental Releases Conducted at Glen Canyon Dam during Water Year 2019
- Possible LTEMP Experiment: Fall 2018 HFE PPT
- 2018 High Flow Experimental Release Decision Memorandum
- Final Tech Team Report: Recommendation to Implement a Fall 2018 High Flow Experiment at Glen Canyon Dam, November 5-8, 2018
COMPLIANCE
- News Release: Interior Initiates High-Flow Experiment at Glen Canyon Dam
- Media Advisory: High-Flow Experiment at Glen Canyon Dam
CONCERNS
ADDITIONAL
- AZ Central news article: Controlled flood of the Grand Canyon begins a four-day exercise on the Colorado River
- Grand Canyon flood fattened fish, but it's not all good news on the Colorado River
- Lighted bypass tube video
- Colorado River Pearce Ferry Rapid After High Flow Release From Glen Canyon Dam
- NPS: November 2018 High-Flow Experiment
