Lower Green River Basin (12)
June 1997

Snow
The Blacks Fork drainage snow water equivalent (SWE) is 77 percent of average. Henry's Fork is melted out as of June 1. Snowpack in the Hams Fork, as of June 1, is 124 percent of average. The basin as a whole is 110 percent of average. For more information see Basin Summary of Snow Courses at beginning of this report.

Precipitation
Precipitation was below average throughout the basin during May. Precipitation ranged from 39 to 78 percent of average from the 4 reporting stations. The entire basin received 66 percent of average for the month (44 percent of last year). The basin year to date precipitation is currently 124 percent of average; sites range from 110 to 137 percent of average.

Reservoir
Fontenelle Reservoir is currently storing 212,900 acre feet; this is 109 percent of average storage. Flaming Gorge did not report this month. Viva Naughton is currently at 39,900 acre feet (117 percent of average).

Streamflow
Water users can expect above average yields in the basin this season. The following forecast values are based on a 50 percent chance probability for the April to July forecast period. Yields will be 100 percent of average for State Line Reservoir inflow (30,000 acre feet) 159 percent of average (105,000 acre feet) at Hams Fork near Frontier. Green River near Green River is forecast to yield 1,300,000 acre feet (145 percent of average). Meeks Cabin Reservoir inflow is estimated to flow 100,000 acre feet (104 percent of average). Viva Naughton Reservoir inflow will be about 143,000 acre feet (154 percent of average). Flaming Gorge Reservoir inflow should be near 1,650,000 acre feet (138 percent of average). 

==================================================================================================================================
                                                     LOWER GREEN RIVER BASIN
                                               Streamflow Forecasts - June 1, 1997
==================================================================================================================================
                                              |  <<====== 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 R nr Green River, WY           APR-JUL      1178      1252    |     1300       145    |      1348      1420            899
                                                                    |                       |
MEEKS CABIN RESERVOIR Inflow         APR-JUL        87        95    |      100       104    |       105       113             96
                                                                    |                       |
STATE LINE RESERVOIR INFLOW          APR-JUL        25        28    |       30       100    |        32        35             30
                                                                    |                       |
HAMS FORK nr Frontier                APR-JUL        90        99    |      105       159    |       110       119             66
                                                                    |                       |
VIVA NAUGHTON RES inflow             APR-JUL       123       135    |      143       154    |       151       163             93
                                                                    |                       |
FLAMING GORGE RES INFLOW             APR-JUL      1375      1564    |     1650       138    |      1736      1926           1196
                                                                    |                       |
==================================================================================================================================
                         LOWER GREEN RIVER BASIN                        |                 LOWER GREEN RIVER BASIN
             Reservoir Storage (1000 AF) - End of May                   |        Watershed Snowpack Analysis - June 1, 1997
==================================================================================================================================
                                      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    212.9    131.0    195.5 |   HAMS FORK RIVER             3        70       124
                                                                        |
FLAMING GORGE                                   NO REPORT               |   BLACKS FORK                 2        55        77
                                                                        |
VIVA NAUGHTON RES                       42.4     39.9     37.3     34.0 |   HENRYS FORK                 2         0         0
                                                                        |
                                                                        |   GREEN above Flaming Gorge  18        57       110
                                                                        |
==================================================================================================================================
 * 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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