Upper Bear River Basin (13)
March 1998

Snow
Snow water equivalent (SWE), at data sites in the Bear River above the Idaho State Line, is 95 percent of average (61 percent of last year). SWE for the Bear River in Utah is estimated to be 93 percent of average; that is about 38 percent less than last year at this time. SWE in the Wyoming portion of the Bear River drainage (Smiths and Thomas Forks) is estimated to be 92 percent of average (60 percent of last year at this time.). See the Basin Summary of Snow Course Data at the beginning of this report for more detailed information.

Precipitation
Precipitation for the month of February was 101 percent of average for the three reporting stations; this is 246 percent of February last year. The year-to-date precipitation figure for the basin is 89 percent of average; this is 60 percent of last year.

Reservoir
Woodruff Narrows reservoir is currently storing 46,000 acre feet compared to 30,200 acre feet last year.

Streamflow
The 50 percent chance stream flow yields are expected to be below average in the Bear River drainage. The Bear River near the Utah - Wyoming State Line is expected to yield 107,000 acre feet; that is 85 percent of average. The Thomas Fork drainage is estimated to yield 29,000 acre feet or 81 percent of normal for the April-September period. The 50 percent chance yield for Smiths Fork near Border is about 105,000 acre feet (89 percent of normal) for the April-September period. The Bear River near Woodruff is expected to yield 127,000 acre feet, about 85 percent of normal for the April-July period. 

==================================================================================================================================
                                                      UPPER BEAR 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)
====================================================================|=======================|=====================================
SMITHS FK nr Border, WY              APR-SEP        75        92    |      105        89    |       120       147            118
                                                                    |                       |
THOMAS FK nr WY-ID State Line        APR-SEP      17.0        23    |       29        81    |        36        50             36
                                                                    |                       |
Bear R nr UT-WY State Line           APR-SEP        79        95    |      107        85    |       121       145            126
                                                                    |                       |
BEAR R nr Woodruff, UT               APR-JUL        72       101    |      127        85    |       160       224            149
                                                                    |                       |
==================================================================================================================================
                         UPPER BEAR RIVER BASIN                         |                 UPPER BEAR 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
========================================================================|=========================================================
WOODRUFF NARROWS                        57.3     46.0     30.2      --- |   UPPER BEAR RIVER in Utah    5        62        93
                                                                        |
                                                                        |   SMITHS & THOMAS FORKS       4        60        92
                                                                        |
                                                                        |   BEAR RIVER abv ID line      9        61        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.
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