GCDAMP- HFE 2015

High Flow Experiment- 2015

2015 High Flow Experiment Snapshot

The 2015 Fall HFE was canceled due to the discovery of green sunfish in Glen Canyon

Sediment Conditions

Fall Accounting Period

Paria River gage at Lees Ferry

• Paria input (Jul 1 - Nov 8): 1,168,498
• Accumulated in Upper Marble Canyon (Jul 1 - Nov 8, lower bound) = 563,000
• Accumulated in Lower Marble Canyon (Jul 1 - Nov 8, lower bound) = 214,000
• Available for HFE: 563,000 + 214,000 = 777,000

Spring Accounting Period

Upper Marble Canyon

• Paria input (Dec 1 to Apr 1): 32,000
• Evacuated from Upper Marble Canyon (Dec 1 to Apr 1, lower bound) = -517,000
• Accumulated in Lower Marble Canyon (Dec 1 to Apr 1, lower bound) = 37,000
• Available for spring HFE: 32,000 - 517,000 + 37,000 = -448,000

Lower Marble Canyon

SUPPORTING DOCUMENTS

• Approval of Recommendation for No Experimental High-Flow Release from Glen Canyon Dam, November 2015
• Final Recommendation to Not Implement a Fall 2015 High Flow Experiment at Glen Canyon Dam
• Updates on 2014 HFE, 2015 Paria sediment inputs, and 2015 sediment mass balance

CONCERNS

• Green Sunfish Lepomis cyanellus; Risk Assessment for the Colorado River ecosystem (CRe)
• Invasive species threats: Green sunfish

ADDITIONAL

• Green Sunfish Removal in a Colorado River Backwater Below Glen Canyon Dam
• Colorado River Slough Green Sunfish Removal
• Green Sunfish Rapid Response Treatment, Nov 2-6 and Nov 12-13, 2015 Brief Treatment Summary
• Installation of Nets to Contain Green Sunfish in Minus-12-Mile Slough, Glen Canyon National Recreation Area, Oct 6-7, 2015 Trip Report
• Desert News: Rapid response treatment to remove invasive green sunfish from a backwater slough
• Green Sunfish Rapid Response Non-native Fish Control in Glen Canyon National Recreation Area

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