WSP00617

• File Number: 8282.600.40
• Description: Colorado River Annual Operation
• Basin: Colorado Mainstem
• Date: 1/1/1999
• Author: UCRC
• Title: Content and Streamflow of Selected Colorado River Basin Reservoirs and Tributaries
• Water Supply Pro - Doc Type: Publication

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STREAMFLOW
Streamflow for the Colorado River, Green River and San Juan River stations for July 1999 are
shown in Table 2. Data presented in the following table was obtained from the monthly report of
streamflow and reservoir contents in the Upper Colorado River Basin, as provided by the U.S.
Geological Survey Water Resources Division, Utah District. A comparison of monthly
streamflow to average monthly streamflow during an 84 year period from 1914 to 1997 is
presented for each in figure 2 on page 4.

JULY
DISCHARGE
(1000 aJ.)

Streamflow for the Colorado River, Green River and San Juan River, July 1999
CUMULATIVE % OF 84 YEAR
% OF 83 YEAR MONTHLY (1914-1997)
(1914-1996) (JULY 99) CUMULATIVE
JUL Y DISCHARGE DISCHARGE
DISCHARGE (1000 A.F.) (JULY 99)

Table 2.

Colorado River

nem- Cisco, Ut

Adjusted (a)

Green River

at Green River, Ut

Adjusted (b)

San Juan River

near Bluff, Ut

Adjusted (c)

Total

Adjusted Total

Colorado River

at Lees Ferry (d) 1121.0

(8) Adjusted for change in storage in Blue Mesa Reservoir. Storage began in Blue Mesa Reservoir on October 27. 1965.
(b) Adjusted [or change in storage: in Flaming Gorge and Fontenelle Reservoirs. Storage began in Flaming Gorge Reservoir
on November I, 1962. and in Fontenelle Reservoir in October of 1964.
(c) Adjusted tor ch3nge in Navajo Reservoir. Storage began on June 27. 1962. Not adjusted for San Juan-Chama
diversions.
(d) Including the Paria River discharge.

538.9
574.3

120%

3949.6
4153.8

84%

457.5
566.2

116%

4918.6
4830.4

118%

168.6
245.7
\3862

155%

1199.1
1513.2

98%

FORECAST
According to the August 16th r.ud-month forecast, the April through Juiy inflows ranged from
97%-144% of average. The August through October forcast ranges from 87%-154%, with Lake
Powell increasing to 106% of average.
Table3. Flow comparisons of the Upper Colorado Basin Reservoirs
Average Average Percent of
Total Flow Flow Percent of F orcas! Flow Average
Apr-Jul 1999 Apr-Jul A veragc Aug-Oct 1999 Aug-Oct F orecasled
( 1000 af) ( 1000 a.f.) Flow (1000 a.f) (1000 a.f) Flow
F ontencUe 1219 848 144% 225 260 87%
Flaming Gorge 1706 1197 143% 275 315 87%
Blue Mesa 676 698 97% 195 180 108%
Navajo 763 679 H2% 275 178 154%
Lake Powell 7655 7735 99% 2200 2080 106%
Upper Basin Total 12019 11157 108% 3170 3013 105%