Colorado Basin Outlook Report March 1 2005

• Description: Colorado Basin Outlook Report March 1 2005
• State: CO
• Date: 3/1/2005
• Author: Green, Allen; Knight, Bruce
• Title: Colorado Basin Outlook Report March 1 2005
• Water Supply Pro - Doc Type: Report/Study

ARKANSAS RIVER BASIN
as of March 1, 2005
Mountain Snowpack* (inches)
Current —sic -- Average
—W-- Maximum Minimum
18
16
14
12
10
.3
8
W
L
6
4
2
0
Jan Feb Mar Apr May
*Based on selected stations
Overall, the Arkansas River Basin snowpack is slightly above average at 115% of average for
March 1. However, measurements from the Upper Arkansas Basin report slightly below
average conditions (99% of average), while the Cucharas & Huerfano River Basins and the
Purgatoire River Basin show well above average snowpacks (151 % of average and 163% of
average, respectively). Basin -wide, this is the first above average March 1 measurement since
1997. Precipitation during February was 93% of average. Despite the below average monthly
precipitation, the total precipitation since October 1 remains above average. By comparison,
this year's water year -to -date totals for the basin are 24% higher than they were a year ago. At
65% of average, reservoir storage continues to lag well below the norm although this year's
storage shows a marked improvement (up 23 %) over last year's totals. Indicative of the
snowpack conditions observed throughout the basin, streamflow forecasts range from a low of
100% of average for Chalk Creek near Nathrop to a high of 148% of average for Grape Creek
near Westeliffe and for the Huerfano River near Redwing.
Precipitation*
(%
of average)
■Monthly DYear -to -date
140
120
100
L
Q
80
o
C
60
L
a
a
40
I
20
Oct Nov Dec
Jan
Feb Mar Apr May
Overall, the Arkansas River Basin snowpack is slightly above average at 115% of average for
March 1. However, measurements from the Upper Arkansas Basin report slightly below
average conditions (99% of average), while the Cucharas & Huerfano River Basins and the
Purgatoire River Basin show well above average snowpacks (151 % of average and 163% of
average, respectively). Basin -wide, this is the first above average March 1 measurement since
1997. Precipitation during February was 93% of average. Despite the below average monthly
precipitation, the total precipitation since October 1 remains above average. By comparison,
this year's water year -to -date totals for the basin are 24% higher than they were a year ago. At
65% of average, reservoir storage continues to lag well below the norm although this year's
storage shows a marked improvement (up 23 %) over last year's totals. Indicative of the
snowpack conditions observed throughout the basin, streamflow forecasts range from a low of
100% of average for Chalk Creek near Nathrop to a high of 148% of average for Grape Creek
near Westeliffe and for the Huerfano River near Redwing.