7762

• UCREFRP Catalog Number: 7762
• Author: Valdez, R. A. and B. R. Cowdell.
• Title: Annual Summary Report-1994, Effects of Flow Regulation and Ice Formation on Overwinter Nursery Habitat of Age-0 Colorado Squawfish in the Green River Below Flaming Gorge Dam.
• USFW Year: 1994.
• USFW - Doc Type: \
• Copyright Material: NO

Table 1.

Table 2.

Table 3.

Table 4.

Table 5.

Table 6.

Table 7.

Figure 1.

Figure 2.

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Figure 6.

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Sites referenced in this report, with associated river miles and distance downstream

from Flaming Gorge Dam. ............................................. 3

Purpose and dates of fields trips conducted for the Winter Ice Study below Flaming

Gorge Dam. ........................................................ 3

Summary of average monthly releases (cis) from Flaming Gorge Dam for December

1993 through February 1994. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 5

Summary of average monthly flows (cis) and monthly volumes (acre-ft) for the Green
River near Jensen, Utah (September 1993 - March 1994) and average post-
impoundment monthly flows (1976 - 1990). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 6

Summary of minimum physical and chemical habitat requirements for backwaters
sampled during the Winter Ice Study. .................................... 11

Summary of average surface ice thickness, free water depth, temperature and
dissolved oxygen for 14 backwaters sampled during Ice Measurement Trip I (January
31 - February 4, 1994 and Trip II (February 21 - 24, 1994) of the Winter Ice Study,

1993-94. .......................................................... 12

Summary of overwinter habitat suitability of 14 backwaters sampled during the

Winter Ice Study, 1993-94. ............................................ 15

liST OF FIGURES

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General location and sampling reaches for the Green River Winter Ice Study. . . . . . .. 2

Representative average and extreme hourly releases from Flaming Gorge Dam for

January and February, 1994. ............................................ 6

Mean daily flow of the Green River near Jensen, Utah for September 1993 - March

1994. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 7

Average monthly maximum and minimum air temperatures for the winter of 1993-94,
compared to average temperatures recorded at the NOAA weather station in Jensen,
UT (average calculated from daily minimum and maximum temperatures. .......... 7

Water temperature in the Green River, 1993-94, as recorded at the USGS stream
gage near Jensen, UT. Temperatures are daily instantaneous values. . . . . . . . . . . . . .. 8

Beginning and duration of river ice formation, overlaid on river water temperatures
and minimum daily air temperatures recorded near Jensen, UT for winters 1986-87,

1987-88 and 1993-94. ................................................. 9

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