DWR_4151909

• Title: JUNE 1998 SWSI: COLORADO WATER SUPPLY CONDITIONS UPDATE, SURFACE WATER SUPPLY INDEX
• Year: 1998
• Document Type - Publications and Reports: SWSI Monthly Report

•
RIO GRANDE BASIN June, 1998
Basinwide Conditions Assessment:
The SWSI value of 0.5 indicates that for May the Rio GRANDE BASIN
)asin water supplies were near normal. Flow at the gaging 5 Surface Water Supply ' "l.tary
station Rio Grande near Del Norte averaged 2,687 cfs, as 4_
compared to the long term average of 2,441 cfs. The Conejos is 3-
1
. 1.A.,' ..Ill
River near Mogote had a mean flow of 968 cfs (87% of
i .
normal). Storage in Platoro, Rio Grande, and Santa Maria 2-• { J ;; F "- '-- -
reservoirs totaled 56% of normal as of the end of May. 1 .. ..�. -- -�--
Precipitation in Alamosa was only 0.01 inches, 0.63 D ' 'ti �. T1 �� '"""
inches below normal. Temperatures ranged from 19°to 71° -1�� „% : 1
in Alamosa where the average monthly temperature was ! 4
a -2_ ✓ ,
51.0°, 0.6° above normal. a f
Stream flow in the basin was generally near average. -3' d
Most streams have already peaked. Flooding will not be a -4 , 1
JAN89 JAN90 JAN91 JAN92 JAN93 JAN94 JANOS JAN99 JAN97 JAN98
concern this season unless a major rain storm occurs. The ..p/..,.
entire basin experienced a very dry month. Dry and dusty
conditions already exist.
Outlook
A month ago the Natural Resources Conservation R I O GRANDE NR. DELNORTE
Service stream flow forecasts were predicting an above 1., °w WATER TEAR
average runoff to be likely, with stream flow on the Conejos 1
and the Rio Grande expected to be about 108% of average. 0.9
However, these predictions have now been downgraded to z 0.8
95% of normal. If precipitation remains low the basin could 07 -
experience a moderate drought. }l 0.8
o_
J—
Y :.:
.
;"Administrative/Management Concerns ;
Wind. This four-letter word has become the source of I 0.3
may disparaging remarks over the last month. A fair bit of
0.2
San Luis Valley topsoil may be in the Midwest by now. Steady
persistent winds have quickly reduced both soil moisture
Oct Nov Dec Jan Rap Marct April May June July Aug Sept
content and snowpack over the last several weeks. ,.N,,,
Reservoirs in the head waters areas of the Rio Grande ° �`�'�°� O DRv�1977� o x 1996
did not store in priority this spring, and are not expected to
do so until storage season this fall. Storage releases are
expected to begin early to offset the dry conditions, but the
run won't last long as storage in those reservoirs is already REPRESENTATIVE RESERVOIRS
low. .5 RIO GRANDE BASIN
24
Public Use Impacts 22
Harsh weather conditions have affected agricultural = e
work to a great decree this spring. b, 16
.I
14 / .\
i 18
4
RIO Grande Platoro SantaNerla
® Avg. 5/31 Contents ® 5/31/9R oont.nta
5