WSP02336

• File Number: 8281.400
• Description: Colorado River Studies and Investigations -- Colorado River Depletion Projections
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 3/5/1990
• Author: US Fish and Wildlife
• Title: Biological Opinion - Stagecoach Reservoir Project
• Water Supply Pro - Doc Type: Biological Opinion

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estimated average annual depletion of 8,926 af was developed with the aid of
W. W. W~eeler studies (Wheeler, 1985). The 8,926 af depletion was derived
from the following scenario which represents the best available information.
Table 2 ~ummarizes this depletion information.

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" y
~' .f '
~ \,J .~.b ','
........ r v ~r)' .
;p~ Ii t'" Y Ste..boa~ Lake
~~ r" Elkhead lleservoir
~ Lake Catplount
11,..(" f{ Yawcolo leservoir

; ,V ~' Toeal Acre Feet

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TABLE 2 -n,fJ..,
Evapor- Hayden Craig \ 1~~en..O
ation Units Units Municipal Agriculture
\
F /O.s-r
383 67i- 188 0 0
658 0 2580 0 0 6>11
0 0 0 0 0 0
286 0 159 1000 3000 12)''''
-

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!. 2927 1000
.

T;~ ' ,1i-E

;;t;;.,.,.ft iN 6 II-- """'" t
The scenario was used to develop. an operation table for the 8,926 af
depletio~ Records of historic reservoir operation in the Ya.pa River basin
were obt:&1ned fro. the Colorado Division 6 Water Resource Office in Steamboat
Springs.!and were used as a basis for distributing the depletions ,in the
months "of .Harch, April, -Hay, June, and.July. This information, along w.ith the
other de~letion information contained in Table 3 below, was converted into a
HYDROSS ~ble for the environmental baseline simulation. ' The results of the
simulatipn pronded the environmental baseline which was used to evaluate the
effects of the Project.

1327

672

3000

Grand Total

8,926

~

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.

TABLE 3

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COMPLETED SECTION 7 CONSULTAnONS
YAHPA RIVER DRAINAGE

Craig Power Ststion Expansion Yampa River
Private Actions Reasonably Certain
To Occur
Cheyenne Stage II Little Snake

6.4 kaf 1.
8.9 kaf)

c ~O ,.f
I ~I

15.8 kaf

Total Depletion~bove
Green River Confluence

31.1 kaf

The fina~ step of this cumulative analysis adds the Project depletion to the
environmental baseline. Stagecoach Reservoir was modeled to approximate the
operatiobs study as presented in Run A of the W. W. Wheeler memorandum dated
April 1,' 1985 (Wheeler, 1985). Run A provides for a yearly release of 2,000
af for m~nicipal use and a 25 cfs industrial release to supplement a junior
right held hy Colorado-Ute.