GCDAMP- HFE 2016
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| High Flow Experiment- 2016 | |
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Contents
2016 High Flow Experiment Snapshot
- The 2016 HFE represents the 4th controlled high flow release conducted under the HFE Protocol.
- A preliminary analysis of these images indicates that sandbar size increased at 55% of sites, remained unchanged and 30% of sites, and decreased at 15% of sites, a response similar to those observed during each of the 2012-2014 HFEs.
- Before and after images from the November 2016 HFE from each of the 45 sandbar sites monitored with remotely deployed digital cameras are available here.
Sediment Conditions
Fall Accounting Period
- Paria input (Jul 1 - Nov 6): 844,748
- Accumulated in Upper Marble Canyon (Jul 1 - Nov 6, lower bound) = 373,000
- Accumulated in Lower Marble Canyon (Jul 1 - Nov 6, lower bound) = 72,000
- Available for HFE: 373,000 + 72,000 = 445,000
- Paria input (Nov 7 - 12): 1,000
- Evacuated from Upper Marble Canyon (Nov 7 - 12, lower bound) = -492,000
- Evacuated from Lower Marble Canyon (Nov 7 - 12, lower bound) = -184,000
- Left over in Marble Canyon after HFE (Nov 7 - 12): 445,000 + 1,000 - 492,000 - 184,000 = -230,000
- Paria input (Dec 1 to Apr 1): 160,000
- Evacuated from Upper Marble Canyon (Dec 1 to Apr 1, lower bound) = -241,000
- Evacuated from Lower Marble Canyon (Dec 1 to Apr 1, lower bound) = -81,000
- Available for spring HFE: -241,000 - 81,000 = -322,000
HFE Details
Schedule & Duration
- Nov. 7 - 6 a.m. begin upramp to powerplant capacity ( ~21,000 cfs)
- Nov. 7 - 10:00 a.m. open bypass tubes, reach full bypass at 12:00 p.m.
- Nov. 11 - 12:00 p.m. end of bypass
- Nov. 12 - 3:00 a.m. end of HFE
- Total duration: 5 days & 5 hours (96 hours at peak release)
Ramp Rates
- Ramp up: 4,000 cfs/hr from 6,500 - 21,000 cfs, then 3,750 cfs/hr to peak (36,000 cfs)
- Ramp down: 1,875 cfs/hr from 36,000 - 21,000 cfs, then 1,500 cfs/hr to 9,000 cfs
HFE Release Details
- Maximum total release: 36,000 cfs
- Powerplant capacity: 21,000 cfs
- River outlet tubes: 15,000 cfs
- Hydropower generation units available: 6
- 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 2.5 feet during the 5-day period
- Estimated acre feet of water bypassed during HFE: 125 kaf
- November volume = 745 kaf
Costs
- Estimated costs to hydropower: $1.4 million
- Actual costs to hydropower: 1.15 million
- Direct expenses for removal of concession assets: TBD
SUPPORTING DOCUMENTS
- Financial Analysis of Experimental Releases Conducted at Glen Canyon Dam during Water Year 2017
- Fall 2016 HFE Planning
- Technical Team Memo: Final Recommendation to Implement a Fall 2016 High Flow Experiment at Glen Canyon Dam
- Leadership Team Memo: Approval of Recommendation for Experimental High-Flow release from Glen Canyon Dam, November 7-12, 2016
COMPLIANCE
CONCERNS
- Grand Canyon Private Boater's Association (GCPBA) letter requesting slower downramp rates following the Fall 2016 High flow experiment.
- Angler's concerns regarding a Fall 2016 High flow experiment on foodbase, trout condition, and disbursement of green sunfish. Also, noted that a comprehensive written three year review of the first three HFEs has not been provided yet.
- Re-emergence of green sunfish in the -12 Mile Slough.
- Increase in brown trout spawning and the increased prevalence of adult brown trout in the Lees Ferry reach since the beginning of the HFE Protocol.
ADDITIONAL
