Upper Bear River Basin (13)
April 2000

Snow
Snow water equivalent (SWE), at snow courses in the Bear River above the Idaho State line, is 83 percent of average (87 percent of last year). SWE for the Bear River in Utah is estimated to be 87 percent of average; that is about 98 percent of last year at this time. SWE in the Wyoming portion of the Bear River drainage (Smiths and Thomas Forks) is estimated at 84 percent of average (83 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 March was 91 percent of average for the 2 reporting stations; this is 100 percent of the previous March. The monthly percentages range from 19 to 95 percent of average. The year-to-date precipitation, for the basin, is 78 percent of average; this is 77 percent of last year's amount.

Reservoir
Woodruff Narrows reservoir is currently storing 57,300 acre feet of water. Current storage is 100 percent of the 57,300 acre feet capacity. Last year the reservoir was storing 57,300 acre feet (100 percent of last year at this time).

Streamflow
The following 50 percent chance stream flow yields are for the April through September period. Smiths Fork near Border is estimated to yield 94,000 acre-feet (80 percent of normal), and Thomas Fork drainage near the Idaho-Wyoming state line is estimated to yield 23,000 acre-feet or 64 percent of normal. Bear River near the Utah-Wyoming State Line is expected to yield about 104,000 acre feet; that is 83 percent of average, while Bear River near Woodruff is expected to yield about 120,000 acre-feet, about 78 percent of normal. 

==================================================================================================================================
                                                      UPPER BEAR RIVER BASIN
                                               Streamflow Forecasts - April 1, 2000
==================================================================================================================================
                                              |  <<====== 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        70        84    |       94        80    |       106       126            118
                                                                    |                       |
THOMAS FK nr WY-ID State Line (Disc. APR-SEP      14.3      19.0    |       23        64    |        28        37             36
                                                                    |                       |
Bear R nr UT-WY State Line           APR-SEP        81        94    |      104        83    |       115       133            126
                                                                    |                       |
BEAR R nr Woodruff, UT               APR-SEP        71        97    |      120        78    |       148       202            154
                                                                    |                       |
==================================================================================================================================
                         UPPER BEAR RIVER BASIN                         |                 UPPER BEAR RIVER BASIN
             Reservoir Storage (1000 AF) - End of March                 |        Watershed Snowpack Analysis - April 1, 2000
==================================================================================================================================
                                      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     57.3     57.3      --- |   UPPER BEAR RIVER in Utah    7        98        87
                                                                        |
                                                                        |   SMITHS & THOMAS FORKS       4        83        84
                                                                        |
                                                                        |   BEAR RIVER abv ID line      9        87        83
                                                                        |
                                                                        |   NORTHWEST                  77        77        86
                                                                        |
                                                                        |   NORTHEST                   20       104        84
                                                                        |
                                                                        |   SOUTHEAST                  24       110        93
                                                                        |
                                                                        |   SOUTHWEST                  29        90        89
                                                                        |
==================================================================================================================================
 * 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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