WSP02851

• File Number: 8271.300
• Description: Colorado River Basin Salinity Control Program - General Information and Publications-Reports
• Basin: Colorado Mainstem
• Water Division: 5
• Date: 10/19/1982
• Author: LJ Paulsen
• Title: Use of Hydroelectric Dams to Control Evaporation and Salinity in the Colorado River System
• Water Supply Pro - Doc Type: Report/Study

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x 109m3) as the initial discharge rate. Salinity decreases
projected to occur from the Las Vegas Wash, Nevada and Grand
Valley, Colorado Salinity Control Projects [3] were also in-
corporated in the salinity model.

RESULTS AND DISCUSSION

Temperature and Discharge Cycles

The construction of Glen Canyon Dam in 1963 drastically
altered the seasonal temperature and discharge cycles in the
Colorado River (Figure 2). River temperatures have increased
by nearly 50C during the late fall and winter but decreased
by 100C during the rest of the year. These temperature
changes were caused by cold-water releases from Glen Canyon
pam. Water is withdrawn from the hypolimnion of Lake Powell,
and discharge temperatures average about BOC throughout the
year, In the summer, river temperatures increase to 10-110C
at Grand Canyon and 15-160C at Pierce Ferry, where the river
enters Lake Mead. However, river temperatures are still
nearly 100C colder than for comparable spring and summer
periods prior to 1963.

1944-62 I/r//]"\\ 1

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1965 - 77

35

DISCHARGE

m 30
g

K 25

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30

TEMPERATURE

25

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1963 -77

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OCT.

NOV.

DEC.

JAN. FEB. MAR. APR. MAY JUNE JULY AUG. SEPT.
MONTH

F'igure 2. Historical Temperature and Discharge Data (:!:SD)
in Grand Canyon for Pre-and Post-Lake Powell
Periods [USGS Data]. From [7].

6

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