Wind River Basin (3)
January 2002

Snow
The Wind River basin has much below average snow water equivalent (SWE) for this time of the year. SWE in the Wind River above Dubois is 89 percent of average (120 percent of last year). The Little Wind SWE is 47 percent of average water content (96 percent of last year), and the Popo Agie drainage SWE is about 71 percent of average (97 percent of last year). The Wind River basin, above Boysen Reservoir, SWE is about 72 percent of average (about 111 percent of last year). See the Basin Summary of Snow Course Data at the front of this report for details.

Precipitation
December precipitation in the basin varied from 8 to 100 percent of average. December precipitation for the basin was about 85 percent of average for the 8 reporting stations; that is about 110 percent of last year's amount. Water year-to- date precipitation is 69 percent of normal. The current water-year-to-date average is about 110 percent of last year at this time. Year to date figures range from 37 to 86 percent of average.

Reservoirs
Current storage varies from 13 to 125 percent of average. Bull Lake is currently storing about 28,400 acre feet (19 percent of capacity) -- normally the reservoir is at 57 percent of capacity at this time of the year. Boysen Reservoir is storing about 14 percent of capacity 82,800 acre feet) -- normally the reservoir is at 104 percent of capacity at this time of the year. Pilot Butte is storing 80 percent of capacity (25,300 acre feet) -- normally the reservoir is at 64 percent of capacity at this time of the year.

Streamflow
Water supply is estimated to be below normal this year. The following values reflect the 50 percent chance yields for the April through September runoff period. The Wind River above Bull Lake Creek is expected to yield 335,000 acre feet (63 percent of average). Wind River at Riverton will yield about 320,000 acre feet (50 percent of average). Boysen Reservoir inflow will yield about 440,000 acre feet (54 percent of normal). Bull Lake Creek near Lenore is expected to yield about 100,000 acre feet (55 percent of average). Little Popo Agie River near Lander is expected to yield about 30,000 acre feet (57 percent of average). South Fork of Little Wind near Fort Washakie will yield about 49,000 acre feet (58 percent of average). Little Wind River near Riverton will yield about 180,000 acre feet (57 percent of average). 

==================================================================================================================================
                                                         WIND 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)
====================================================================|=======================|=====================================
WIND RIVER abv Bull Lake Cr (2)      APR-SEP       155       262    |      335        63    |       408       515            535
                                                                    |                       |
WIND RIVER at Riverton (2)           APR-SEP        33       204    |      320        50    |       436       607            640
                                                                    |                       |
BOYSEN RESERVOIR Inflow (2)          APR-SEP        88       298    |      440        54    |       582       792            809
                                                                    |                       |
BULL LAKE CR near Lenore (2)         APR-SEP        41        76    |      100        55    |       124       159            182
                                                                    |                       |
LT POPO AGIE RIVER nr Lander         APR-SEP      11.7        23    |       30        57    |        43        62             53
                                                                    |                       |
SF LT WIND nr Fort Washakie          APR-SEP      19.1        37    |       49        58    |        61        79             84
                                                                    |                       |
LT WIND RIVER nr Riverton            APR-SEP        83       141    |      180        57    |       249       351            315
                                                                    |                       |
==================================================================================================================================
                            WIND RIVER BASIN                            |                    WIND 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
========================================================================|=========================================================
BULL LAKE                              151.8     28.4     62.5     86.3 |   WIND RIVER above Dubios     3       120        89
                                                                        |
BOYSEN                                 596.0     82.8    457.1    620.4 |   LITTLE WIND                 2        96        47
                                                                        |
PILOT BUTTE                             31.6     25.3     23.6     20.2 |   POPO AGIE                   4        97        71
                                                                        |
                                                                        |   WIND above Boysen Resv      7       111        72
                                                                        |
==================================================================================================================================
 * 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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