WSP12942

• File Number: 8040.800
• Description: Water Resources for Colorado
• State: CO
• Date: 5/1/2003
• Author: US Dept of Agriculture - Natural Resoruces Conservation Service
• Title: Colorado Basin Outlook Report May 1, 2003
• Water Supply Pro - Doc Type: Data

SAN MIGUEL, DOLORES, ANIMAS, AND SAN JUAN RIVER BASINS
as of May 1, 2003

Mountain Snowpack* (Inches)

-*-Current -'-Average
___Maximum -+-Minimum

45
40
35
0 30
J
0
.!! 25
.
1:
,
0- 20
OJ
"
.
-
. 15
:=
10
5

/
.) ....... /
l./
./
------ --------
v-: .- "- 1""-
---
/'
~

o
Jan

Feb

Mar

Apr

May

J,n

. Based on selected stations

Precipitation- (% of average)

j_Monthly DYear-lo-date I

100
.
'"
.
"
.
>
<t
- 60.
0
-
0
.
u
"
. 40
0.
20

o

.
Oct Nav Dee Jan Fob Mar Apr May

It appears that these basins will be struggling through another extremely low watcr supply season
this year. The snowpack began to melt in these basins in early April, and if the melt rates continue
most of the snow will be melted by early June, which would be well over a month ahead of the
average melt-out date. The snowpack measurements on May I are only 51 % of average.
Measurements range from 41 % of average in the Dolores Basin, to 62% of average in the San
Juan Basin. Precipitation during April was only 57% of averagc, and the water year total is only
77% of average. There has been 161 % of the amount of precipitation last water year by this time.
Reservoirs in these basins have only 65% of their average storage amount for this time of year,
which is only 87% of last year's storage. Unfortunately, while the snow has been melting, the
streamtlows have not risen as much as would have bccn expected, and the new forecasts retlect
these observations with reduced numbers. They range from only 42% of average at thc intlow to
Navajo Reservoir, to 60% of average on the Dolores River at Dolores.