8157

• UCREFRP Catalog Number: 8157
• Author: Pitlick, J., M. V. Steeter, B. Barkett, R. Cress and M. Franseen.
• Title: Geomorphology and Hydrology of the Colorado and Gunnison Rivers and Implications for Habitats Used by Endangered Fishes.
• USFW Year: 1999.
• USFW - Doc Type: \
• Copyright Material: NO

STUDY AREA
The Colorado River and the Gunnison River have their headwaters in the Rocky Mountains in
central Colorado (Fig. 1). The Yampa River and White River, which are both major tributaries of
the Green River, likewise have their sources in the Rocky Mountains (Fig. 1). The annual
hydrographs of these rivers are dominated by snowmelt runoff which usually begins in late April,
reaches a peak in late May or early June, and recedes through July. Late-summer thunderstorms
can cause localized flooding on tributaries and increase main-stem discharges by 10 to 20%. These
storms can also increase suspended sediment concentrations greatly. Whether the fine sediment
delivered by these storms is detrimental to fish and other aquatic organisms is unknown, but there
is some overlap between the time when Colorado squawfish spawn (from late-June through July)
and the time when these storms normally occur (from mid-July through October).
110 °
108°
106°
WYOMING
-- ----r------ ------ ----------
UTAH
COLORADO
Flaming Gorge
Reservoir
09251000
Yampa River
Jensen 0 I
•

e Ri ver
400
I
o
r
giver
I
Figure 2 G0110
09072500

v Grand
09163500 Junction
09095500
O Green ? •
\
River , _ 09112500
380
Moab
09152500
?i Blue Mesa
?niZtJO Reservoir
jl ?IL
Pr
0 100 km
0 100 mi
110 O
108
106°
40°
38°
Figure 1. Location of major rivers and selected USGS gauging stations that were used to
evaluate long-term trends in streamflow in the upper Colorado River basin. The outlined
area near Grand Junction was the focus of more detailed field studies.
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