Upper Bear River Basin (13)
May 2001

Snow
Snow water equivalent (SWE), at snow courses in the Bear River above the Idaho State line, is 49 percent of average (89 percent of last year). SWE for the Bear River in Utah is estimated to be 56 percent of average; that is about 96 percent of last year at this time. SWE in the Wyoming portion of the Bear River drainage (Smiths and Thomas Forks) is estimated at 49 percent of average (79 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 April was 109 percent of average for the 2 reporting stations; this is 147 percent of the previous April. The year-to- date precipitation, for the basin, is 70 percent of average; this is 90 percent of last year's amount.

Reservoir
Usable storage in Woodruff Narrows Reservoir is 21,500 acre-feet (38 percent of total capacity) The reservoir is currently storing about 38 percent of the amount stored last year at this time.

Streamflow
The upper Bear River drainage is expected to have much below average runoff this spring. The following 50 percent chance stream flow yields are for the April through September period. Smiths Fork near Border is estimated to yield 47,000 acre-feet (43 percent of normal), and Thomas Fork drainage near the Idaho-Wyoming state line is estimated to yield 6,000 acre-feet or 20 percent of normal. Bear River near the Utah-Wyoming State Line is expected to yield about 60,000 acre feet (48 percent of average), The Bear River near Woodruff is expected to yield about 68,000 acre-feet (about 44 percent of normal).

==================================================================================================================================
                                                      UPPER BEAR RIVER BASIN
                                               Streamflow Forecasts - May 1, 2001
==================================================================================================================================
                                              |  <<====== 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              MAY-SEP        37        43    |       47        43    |        52        60            109
                                                                    |                       |
THOMAS FK nr WY-ID State Line (Disc. MAY-SEP       3.8       5.0    |      6.0        20    |       7.2       9.4             30
                                                                    |                       |
Bear R nr UT-WY State Line           APR-SEP        53        57    |       60        48    |        63        68            126
                                     MAY-SEP        50        54    |       57        48    |        60        65            120
                                                                    |                       |
BEAR R nr Woodruff, UT               APR-SEP        44        57    |       68        44    |        81       105            154
                                     MAY-SEP        36        47    |       57        44    |        69        91            131
                                                                    |                       |
==================================================================================================================================
                         UPPER BEAR RIVER BASIN                         |                 UPPER BEAR RIVER BASIN
             Reservoir Storage (1000 AF) - End of April                 |        Watershed Snowpack Analysis - May 1, 2001
==================================================================================================================================
                                      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     21.5     57.3      --- |   UPPER BEAR RIVER in Utah    7        96        56
                                                                        |
                                                                        |   SMITHS & THOMAS FORKS       4        79        49
                                                                        |
                                                                        |   BEAR RIVER abv ID line      9        88        49
                                                                        |
                                                                        |   NORTHWEST                  70        79        50
                                                                        |
                                                                        |   NORTHEST                   17        75        56
                                                                        |
                                                                        |   SOUTHEAST                  35       100        74
                                                                        |
                                                                        |   SOUTHWEST                  35        95        59
                                                                        |
==================================================================================================================================
 * 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 l 

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