7738 ‎(2)‎

• UCREFRP Catalog Number: 7738
• Author: Ruppert, J. B., R. T. Muth and T. P. Nesler
• Title: Predation on Fish Larvae by Adult Red Shiner, Yampa and Green Rivers, Colorado
• USFW Year: 1993
• USFW - Doc Type: The Southwestern Naturalist
• Copyright Material: NO

Executive Summary

Reservoir was drawn down each year due to hydropower operations in an amount of
approximately 7,000 af. Under 2015 demand conditions the storage in Stagecoach was used
infrequently.
In the long-term demand scenario (2040) that includes the enlargement of Stagecoach
' Reservoir, Stagecoach was drawn down an average of 7,365 of per year as additional releases
were made out of its enlargement pool. The average drawdown of Elkhead Reservoir in this
scenario was approximately 17,000 af.
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Table S-9 shows the modeled average monthly flows (cfs) in Juniper Canyon under the
' No Action, 2015 and 2040 demand conditions. Minimum flow conditions typically occurred in
the months of September through February.
' Table S-9
Average Modeled Juniper Canyon Flows (cfs)

No Action With Phased Enlargements
' 2015 2040 2015 2040
October 329 321 325 272
November 306 279 308 275
' December 253 226 255 233
January 234 206 236 212
February 277 246 278 250
March 603 572 595 567
April 2,501 2,460 2,368 2,304
May 5,537 5,484 5,515 5,400
June 4,794 4,732 4,799 4,736
' July 1,102 1,032 1,134 1,106
August 276 221 323 296
September 191 181 243 175

Recovery Program Integration and Recommended Flows
An important criteria in evaluating near-term and long-term water development projects
in the Yampa Basin was the effect of future development on streamflows in the Yampa River at
Deerlodge Park. While transfer of a portion of the Juniper Project water rights to instream
flow purposes at Juniper Canyon may be an important step towards protecting the habitat needs
of the endangered fishes, depletions associated with future water uses were evaluated to assess
their effects on the hydrograph of the river.
' A review of the future basin demands used to establish the interim flow
recommendations suggested that the interim flow recommendations were based on a demand
horizon which falls somewhere between the years 2015 and 2040. For this reason it was
deemed more logical to focus on comparisons between flows predicted under near- and long-
term projects and the No Action alternative, rather than the interim flow recommendations.
This comparison is provided in Table S-9, which suggest that the effects of enlarging and
operating Elkhead and Stagecoach Reservoirs will be to slightly reduce Juniper Canyon flows
' during the early runoff period and to slightly increase flows in the remainder of the year.
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