DWR_4151800

• Title: FEBRUARY 1991 SWSI: COLORADO WATER SUPPLY CONDITIONS UPDATE, SURFACE WATER SUPPLY INDEX
• Year: 1991
• Document Type - Publications and Reports: SWSI Monthly Report

RIO GRANDE BASIN
Basinwide Conditions Assessment:
SURFACE WATER SUPPLY INDEX
The SWSI value of +0.9 indicates that the current S RI Cr Anda Bea In
conditions are above normal. This represents a significant 4-
improvement from conditions on February 1, 1990,when the W 3- , :- i i
SWSI value was -3.6. Snowpack measured on February 1, a = r r
1991, was 102% of average. This is nearly a 400% . . : w •
improvement over last year. Precipitation measured 78% of 3 1- =if :.: ,_,. ii ' '
average for the month of January. Streamflow conditions on 9 a
7. ;-.....i..." ...-i—i— -...!.......j. , i
the Rio Grande and its tributaries in the San Luis Valley were - ;, . .
average for the month. Flow at the key gaging station, Rio . 2_ ' ;'
Grande near Del Norte, averaged 175 cfs for the month of
January as compared to the historic monthly average of 170 3_ 1
cfs. Above average storage occurred in basin reservoirs in -4 , ..
JANY1 JAN/2 JAN93 JANS4 JAN8S JAN39 JAN87 JAN88 JAN88 JAN90 JAN91
January, but overall storage was only 84% of normal on YEAR,MONTH
February 1, 1991. Storage (useable) in Rio Grande Reservoir
was only 9,700 acre-feet on February 1, 1991. This is 59%of
the seasonal average. Soil moisture conditions remain high.
As a result, ground water return flows are expected to
increase in the spring.
RIO GRANDE NR. DELNORTE
Outlook: FLOW 9Y WATER YEAR
170
Adequate storage capacity exists for normal to above "° "
130
normal runoff. Streamflow forecast is lowest in the Saguache 140
Creek drainage above Saguache at 91% of average and is
highest in the Culebra Creek drainage at San Luis at 124%of •
i11p
average. i
i. 100
w�
u
70
Administrative/Management Concerns: ~v
The entire combined flow of the Conejos River and ��'�� J��
Rio Grande (297 cfs) is being delivered to the stateline to 5R o .-
satisfy 1991 compact obligations. The Closed Basin Project 3G ��
continues to make deliveries to the Rio Grande which helps
Oct Nov O. Jan Fab Nor cn
Colorado in meeting its overall Compact commitments. ACAYTH
.ET YEAR(1917) + 1RY YEAR(1177) a AVG ❑ 199
Public Use Impacts:
Wolf Creek ski area has the greatest reported base in
the state. With reservoirs filling at above normal rates, early
prospects for recreation use this summer appear encouraging. Rio Grande Basin Reservoir Supplies
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® AVG. 1/31 Contents ® 1/31/91 Contant8
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