DWR_4151807

• Title: AUGUST 1990 SWSI: COLORADO WATER SUPPLY CONDITIONS UPDATE, SURFACE WATER SUPPLY INDEX
• Year: 1990
• Document Type - Publications and Reports: SWSI Monthly Report

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COLORADO BASIN
Basinwide Conditions Assessment:
The SWSI value of -2.3 indicates that the current SURFACE WATER SUPPLY I NOEX
:onditions signify a moderate drought stage. Although July s Colorado RI vim-rain
precipitation was 158% of normal, the basin tributary flow ,- 1 - i is criticaly low with conditions the worst west and south of - : )
Glenwood Springs. Cumulative flow at the key gaging -
station, Colorado River near Dotsero, is approximately 40% - .: _ =_-E
below normal for the water year and only about 15% above - ---,---�'-
the minimum flow recorded in 1977. GranbyReservoir is o '- "' --"r'" -
977 i� ,1
filling slowly but is relatively low. _,_ f,_ y
c - w
} t - f
Outlook: 0 -�- A
o
Z`
The Colorado River mainstream should have _3-
adequate water supplies available through the remainder of -+ .......-- A
g Shortage will continue in the Grand ' ' ' ` ` .. '"� �'"N"
the irrigation season. 1,011149,,w,
Mesa and Grand Valley areas. The Granby Reservoir water
level will increase slightly but will drop later in the year as
pumping to the Adams Tunnel increases.
Administrative/Management Concerns:
A "river call" was placed on the Colorado River on COLORADO RIVER NR. DOTSERO
July 27, 1990, to satisfy the Shoshone Power Plant right. 3.2 PUN BY
""MYEAR
On July 30, 1990, the "Cameo call" was placed on the z
Colorado River. Decreasing flow in the Colorado River has 2.6
placed a strong demand on storage releases from Green i 2.4
Mountain Reservoir to augment flow. Vega Reservoir is in +
its last 20-day storage release after which there will be no o
replacement or project water available. y 14.4
5 _,�
,.z
Public Use Impacts: a." ��
Starting August 15, a storage release will be made 0.6
from Ruedi Reservoir to the 15 mile stretch below the 0.2
Grand Valley Canal for the endangered fish species in that o Mom, Aprl I Lay Juno July Aug
Sept
area. This will effectively increase flows in the Fryingpan ,0,,,,
and Roaring Fork Rivers. Vega Reservoir is extremely low. ° """('9°'' + Mill(,li77) 0 ♦ 1990
Rifle Gap Reservoir level is below the boat ramp.
Colorado River Basin Reservoir Supplies
1e0
,330/1'\\
10
1 1,0
1 gm
70 , .
if so
/
, :0^ /\.
..,://\
0 ._ ,„. ,,,,,,
Gram Mountain aural t/I I1I//M Fort
® Avg. 7/31 Contras ® 7/31/90 Contents
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