NWS Report Shows Under Average Snowpack

As of April 1, 2012, this year’s snowpack levels were well below average for South Central and Southeast Colorado.

In the upper Rio Grande Basin, the snowpack as at 53% of average overall, down from 83% of average last month at this time, and tracking well behind last year’s 76% of average.  In the Arkansas Basin, the snowpack was at 56% of average overall, down from 86% of average last month at this time and tracking well behind last year’s 103% of average. 

Water year precipitation is running below average across both basins.  As of April 1, the upper Rio Grande Basin reported 91% of average precipitation, down from 103% of average last month, but higher than 83% of average from a year ago.  The Arkansas Basin reported 79% of average precipitation, down from 89% of average a month ago, and lower than 93% of average a year ago. 

Overall reservoir storage is running near or below average across southern Colorado.  Storage in the upper Rio Grande Basin at the end of March was at 73% of overall average, up slightly from 69% of average last month, but down from 82% of average last year at this time.  In the Arkansas Basin, storage was at 86% of average overall, down from 98% of average last month at this time and lower than 90% of average a year ago. 

For the Arkansas Basin, streamflow volumes for the upcoming runoff season are predicted to be below average.  The following are streamflow forecasts for selected locations for the Basin, assuming normal precipitation during the next few months. 

                                                Per Cent of Average       Runoff Period 

Granite                                                 45                           Apr-Sept
Salida                                                   50                           Same
Canon City                                           69                           Same
Above Pueblo                                      51                           Same
Chalk Creek Near Nathrop                44                           Same
Grape Creek/Westcliff                       41                           Same
Huerfano River/Redwing                   63                           Same
Cucharas River/La Veta                     62                           Same
Purgatoire River/Trinidad                61                           Same    

These forecasts reflect natural flow only.  Actual observed flow will likely be affected by upstream water management.  This outlook is based on recent observations of snowpack and assumes normal precipitation for the remainder of the snow season.   An updated outlook will be issued in early May.