Little Snake River Basin (10)
March 1998

Snow
Snowfall has been below average across the basin this year. Currently the basin snow water equivalent (SWE) is 95 percent of average for the year and 65 percent of last year at this time. For more information see Basin Summary of Snow Courses at beginning of this report.

Precipitation
Precipitation across the basin has been close to average. The Little Snake River basin water-year-to-date precipitation is currently 100 percent of average (76 percent of last year). February precipitation was 24 percent above average (130 percent of last year) for the 5 reporting stations. All sites, except Baggs, reported average or above precipitation for the month.

Streamflow
Stream yield, based on the 50 percent probability, is forecast to be 100 percent of average near Slater and 99 percent of average near Dixon. Near Slater the Little Snake should yield about 155,000 acre feet and near Dixon it should be about 325,000 acre feet.
==================================================================================================================================
                                                     LITTLE SNAKE RIVER BASIN
                                               Streamflow Forecasts - March 1, 1998
==================================================================================================================================
                                              |  <<====== Drier ======  Future Conditions  =======  Wetter =====>>  |             
                                              |                                                                     |
  Forecast Point                     Forecast |  ==================== Chance Of Exceeding * ======================  |
                                      Period  |    90%       70%    |  50% (Most Probable)  |      30%       10%    |  30-Yr Avg.
                                              | (1000AF)  (1000AF)  |   (1000AF)  (% AVG.)  |    (1000AF)  (1000AF) |    (1000AF)
====================================================================|=======================|=====================================
LITTLE SNAKE R nr Slater             APR-JUL       117       140    |      155       100    |       170       193            155
                                                                    |                       |
LITTLE SNAKE R nr Dixon              APR-JUL       213       280    |      325        99    |       370       437            329
                                                                    |                       |
==================================================================================================================================
                        LITTLE SNAKE RIVER BASIN                        |                LITTLE SNAKE RIVER BASIN
             Reservoir Storage (1000 AF) - End of February              |        Watershed Snowpack Analysis - March 1, 1998
==================================================================================================================================
                                      Usable |  *** Usable Storage ***  |                            Number     This Year as % of
Reservoir                            Capacity|  This      Last          |   Watershed                  of       =================
                                             |  Year      Year     Avg  |                          Data Sites   Last Yr   Average
========================================================================|=========================================================
                                                                        |   LITTLE SNAKE RIVER          8        65        95
                                                                        |
==================================================================================================================================
 * 90%, 70%, 30%, and 10% chances of exceeding are the probabilities that the actual volume will exceed the volumes in the table.

The average is computed for the 1961-1990 base period.

(1) - The values listed under the 10% and 90% Chance of Exceeding are actually 5% and 95% exceedance levels.                  
(2) - The value is natural volume - actual volume may be affected by upstream water management.


To March 1998 Basin Outlook Report Contents Page