Lower Green River Basin (12)
January 2002

Snow
The Blacks Fork and Henrys Fork drainage's, as of January 1, are below average. SWE in the Hams Fork, as of January 1, is 95 percent of average (115% of last year). Blacks Fork SWE is currently 86 percent of average (86 percent of last year). The basin, as a whole, is 89 percent of average (108 percent of last year). For more information see Basin Summary of Snow Courses at beginning of this report.

Precipitation
Precipitation was above average for the 3 reporting stations during December. Precipitation ranged from 102 to 139 percent of average for the month. The basin year-to-date precipitation is currently 87 percent of average (116 percent of last year). Year to date percentages range from 84 to 91.

Reservoir
Fontenelle Reservoir is currently storing 146,400 acre feet; this is 70 percent of average (96 percent of last year). Flaming Gorge is currently storing 2,873,400 acre feet,this is 98 percent of average (96 percent of last year). Viva Naughton is currently storing 29,000 acre feet; this is 92 percent of average (90 percent of last year).

Streamflow
Expected yields vary from 69 to 77 percent of average across the basin. The following forecast values are based on a 50 percent chance probability for the April through July forecast period. Green River near Green River is forecast to yield about 650,000-acre feet (74 percent of average). Blacks Fork near Robertson is forecast to yield 70,000-acre feet (74 percent of average). East Fork of Smiths Fork near Robertson is estimated to yield 21,000 acre-feet (68 percent of average). The estimated yield for Hams Fork near Frontier is 50,000-acre feet (77 percent of average). Viva Naughton Reservoir inflow will be about 65,000-acre feet (73 percent of average). Flaming Gorge Reservoir inflow will be about 820,000-acre feet (69 percent of average). 

==================================================================================================================================
                                                     LOWER GREEN RIVER BASIN
                                               Streamflow Forecasts - January 1, 2002
==================================================================================================================================
                                              |  <<====== 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)
====================================================================|=======================|=====================================
Green River nr Green River, WY       APR-JUL       342       525    |      650        74    |       775       958            875
                                                                    |                       |
Blacks Fork nr Robertson             APR-JUL        47        57    |       70        74    |        83       101             95
                                                                    |                       |
EF of Smiths Fork nr Robertson       APR-JUL      15.5      18.6    |       21        68    |        24        28             31
                                                                    |                       |
Hams Fk blw Pole Ck nr Frontier      APR-JUL        29        41    |       50        77    |        60        77             65
                                                                    |                       |
Hams Fk Inflow to Viva Naughton Res  APR-JUL        22        48    |       65        73    |        82       108             89
                                                                    |                       |
Flaming Gorge Reservoir Inflow       APR-JUL       394       648    |      820        69    |       992      1246           1190
                                                                    |                       |
==================================================================================================================================
                         LOWER GREEN RIVER BASIN                        |                 LOWER GREEN RIVER BASIN
             Reservoir Storage (1000 AF) - End of December              |        Watershed Snowpack Analysis - January 1, 2002
==================================================================================================================================
                                      Usable |  *** Usable Storage ***  |                            Number     This Year as % of
Reservoir                            Capacity|  This      Last          |   Watershed                  of       =================
                                             |  Year      Year     Avg  |                          Data Sites   Last Yr   Average
========================================================================|=========================================================
FONTENELLE                             344.8    146.4    151.9    209.7 |   HAMS FORK RIVER             3       115        95
                                                                        |
FLAMING GORGE                         3749.0   2873.4   3006.0   2940.8 |   BLACKS FORK                 2        86        86
                                                                        |
VIVA NAUGHTON RES                       42.4     29.0     32.2     31.6 |   HENRYS FORK                 2        69        79
                                                                        |
                                                                        |   GREEN above Flaming Gorge  18       108        89
                                                                        |
==================================================================================================================================
 * 90%, 70%, 30%, and 10% chances of exceeding are the probabilities that the actual volume will exceed the volumes in the table.

(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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