GCDAMP- HFE 2012

SUPPORTING DOCUMENTS

@ RM30 = 390,000 metric tons
@ RM60 = 380,000 metric tons
@ RM87 = 540,000 metric tons
@ RM225 = 970,000 metric tons
At Diamond Creek (RM225), 1,810,000 metric tons were transported by the Colorado River between July 1, 2012, and July 1, 2013. Thus, 54% of the total delivery of sand to Lake Mead reservoir during this 1-year period occurred during approximately 5 days of the November 2012 HFE. For comparison, 45% of the total delivery of sand to Lake Mead reservoir during calendar year 2008 occurred during the 2008 HFE; the 2004 HFE delivered 40% of the total sand delivered to Lake Mead in calendar year 2004.

500,000 tons of sediment is equivelant to filling a football field 230 feet deep (KSalazar)

Cultural: No adverse effects to historic properties of the 2012 HFE were identified. (USBR Memo 2013)
HBC & Native Fish: No measuable positive effect on HBC or other native fish. (Provisional- unpublished data)
RBT Monitoring: RBT in Glen Canyon moved very little during the period around HFE.
Foodbase: Initial results do not indicate a strong effect on food base-- but is expected to take longer to recover over the winter period (GCMRC unpublished data)
Kanab Ambersnail: FWS found in its 2011 BO that this loss of snails/ habitat would not jeopardize the continued existence of the snail
Whirling Disease: HFE's pose little risk of spreading whirling disease (GCMRC Assessment)

Contributor: Category: Sediment, Recreation, Water delivery

High Flow Experiment- 2012