8279

• UCREFRP Catalog Number: 8279
• Author: Brown and Caldwell.
• Title: Phase 1 Coordinated Facilities Water Availability Study for the Endangered Fishes of the Upper Colorado River.
• USFW Year: 2000.
• USFW - Doc Type: \
• Copyright Material: NO

short list of alternatives for further consideration. The extended baseline hydrology will then be
used to determine the sensitivity of the short list alternatives to the hydrology.
2.3.3 Baseline Conditions
For purposes of determining the contribution of each alternative toward the 20,000, acre-feet, the
baseline condition will be the StateMod C1 Scenario, with the RIPRAP projects and without the
60,000 acre-feet or 120,000 acre-feet of new depletions, as detailed in Appendix D of the PBO.
The StateMod C1 Scenario has the following components of RIPRAP flows incorporated into the
scenario:
• 5,000 acre-feet per year from Ruedi Reservoir,
• 5,000 acre-feet in 4 out of 5 years from Ruedi Reservoir,
10,825 acre-feet per year from Ruedi Reservoir under long-term lease,
10,825 acre-feet per year on a permanent basis divided equally between east slope and
west slope water users (presently Williams Fork and Wolford Mountain Reservoirs),
• 6,000 acre-feet per year from Wolford Mountain Reservoir,
• Up to 28,400 acre-feet per year of water resulting from construction of improved water
management features for the Grand Valley Water Management Project.
CROP will not be included in the baseline hydrology to be used in Phase 2. At the conclusion of
investigating each of the alternatives to be analyzed in Phase 2, the alternative will be subjected
to necessary and appropriate sensitivity analysis to determine if CROP is likely to affect the
feasibility of the specific alternative.
Sensitivity analysis will be used in a similar fashion with respect to the 120,000 acre-feet per
year of future depletions. At the conclusion of investigating each of the alternatives in Phase 2,
the alternative will be subjected to necessary and appropriate sensitivity analysis to determine if
feasibility of the alternative is affected by including the 120,000 acre-feet per year of future
depletions in the baseline hydrology.
2.3.4 Flow Targets
As indicated in (1) a memo from the Service (Maddux, February 2, 1999), (2) a meeting with the
Service (April 1, 1999) and (3) the PBO (U.S. Fish and Wildlife Service, 1999, pg. 11), the
Service is first and foremost interested in augmenting the peak of the spring runoff hydrograph
with an additional 20,000 acre-feet of water on an average annual basis. The Service's priority is
to increase spring peak flows when the hydrograph peak is expected to be in the range of 12,900
to 26,600 cfs at the head of the 15-Mile Reach or approximately 29,000 cfs at the Cameo USGS
gage (Coordinated Reservoir Operations Group, 1999 and personal communication from George
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