9397

• UCREFRP Catalog Number: 9397
• Author: Hydrosphere Resource Consultants.
• Title: Gunnison River / Aspinall Unit Temperature Study - Phase I.
• USFW Year: 2002.
• USFW - Doc Type: 107,
• Copyright Material: NO

Gunnison River / Aspinall Unit Temperature Analysis -Phase I
Page 7
To determine the impact of each reservoir, release temperatures from Blue Mesa and
Morrow Point were added to Figure 2 (See Figure 3). Note that releases from-Blue Mesa
and Morrow Point were estimated using profile temperatures at the elevation of the
outlet, taking reservoir elevation into account. Comparisons between profile data and
observed releases when data were available indicated the validity of this technique.
-'Below Blue Mesa -Profiles
18 -+~- Below Morrow Point -Profiles
~-'Below Crystal -Profiles
16 -Below Crystal - FWS
-"Upstream of BMR - NPS
Upstream of BMR -Estimated from CSU
14 -Below Blue Mesa -Estimated from CSU
12
10
8 ~
1 I
6 w
* ffl
4 .
2
0
1 / 1 /93 1 l1 l94 1 l1 /95 1 /1 /96 12/31 /96 12131 /97 12/31 /98 12131 /99 12/30100
Temperature (C)
Figure 3. Gunnison River Temperatures (1993-2000).
It is evident from Figure 3 that the observed cooling is a result of Blue Mesa Reservoir.
Release temperatures from Morrow Point are higher than those from Blue Mesa.
Similarly, release temperatures from Crystal are higher than those from Morrow Point:
Thus, a warming trend exists between the top of Morrow Point and the releases from
Crystal. The temperature differences between each point are more pronounced in the
earlier summer months and taper off in late summer.
A data analysis by reservoir maybe found in the following sub-sections followed by a
summary of the reservoir analysis.
4.1 Data Analysis by Reservoir -Blue Mesa
4.1.1 Physical Data - Morphometry, Hydrology, and Setting
Blue Mesa Reservoir is the largest reservoir in Colorado. It is a long impoundment,
extending about 20 miles, and consists of three major sections or pools -- Iola, Cebolla,
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