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Wyoming Basin Outlook Report for
BIGHORN RIVER BASIN as of March 1, 2012

Snow The Bighorn River Basin SWE above Bighorn Reservoir is at 124% of average. The Nowood River is at 121% of average. The Greybull River SWE is at 117% of average. Shell Creek SWE is 129% of average. See the Basin Summary of Snow Course Data at the front of this report for details. Precipitation Last month's precipitation was 196% of average (201% of last year). Sites ranged from 122-333% of average for the month. Year-to-date precipitation is 123% of average; that is 114% of last year at this time. Year-to-date percentages, from the 10 reporting stations, range from 95-161%. Reservoir Boysen Reservoir is currently storing 608,100 ac-ft (106% of average). Bighorn Lake is now at 855,100 ac-ft (103% of average). Boysen is currently storing 109% of last year volume at this time and Big Horn Lake is storing 100% of last year's volume. Detailed reservoir data is shown on the following page and on the reservoir storage summary at the beginning of this report. Streamflow The 50% exceedance forecasts for the April through September runoffs are anticipated to be slightly above average. Boysen Reservoir inflow should yield 710,000 ac-ft (88% of average); the Greybull River near Meeteetse should yield around 215,000 ac-ft (108% of average); Shell Creek near Shell should yield around 81,000 ac-ft (113% of average) and the Bighorn River at Kane should yield around 1,130,000 ac-ft (102% of average). See the following page for detailed runoff volumes.

Streamflow Forecasts

BIGHORN RIVER BASIN
Streamflow Forecasts - March 1, 2012

 <==== Drier === Future Conditions === Wetter ====> 
Forecast Pt============ Chance of Exceeding * =========== 
   Forecast90%70%50% (Most Prob)30%10%30 Yr Avg
   Period(1000AF)(1000AF)(1000AF)(% AVG.)(1000AF)(1000AF)(1000AF)

Boysen Reservoir Inflow (2)
APR-JUL 260       490       645       90       800       1030       717      
APR-SEP 280       535       710       88       885       1140       809      
Greybull R nr Meeteetse
APR-JUL 120       142       157       106       172       194       148      
APR-SEP 167       196       215       108       235       265       200      
Shell Ck nr Shell
APR-JUL 54       63       69       115       75       84       60      
APR-SEP 64       74       81       113       88       98       72      
Bighorn R at Kane (2)
APR-JUL 510       820       1030       103       1240       1550       1000      
APR-SEP 565       900       1130       102       1360       1700       1110      

    * 90%, 70%, 30%, and 10% chances of exceeding are the probabilities that the
       actual flow will exceed the volumes in the table.

    (1) - The values listed under the 10% and 90% Change of Exceeding are
            actually 5% and 95% exceedance levels.
    (2) - The value is natural flow - actual flow may be affected by upstream
            water management.



Reservoir Storage

BIGHORN RIVER BASIN
Reservoir Storage (1000AF) End of February

 Usable************* Usable Storage *************
Reservoir Capacity This Year Last Year Average

BOYSEN 596.0      608.1         557.8          571.4        
BIGHORN LAKE 1356.0      855.1         853.4          826.3        



Watershed Snowpack Analysis

BIGHORN RIVER BASIN
Watershed Snowpack Analysis - March 1, 2012

 Number ofThis Year as Percent of
Watershed Data Sites Last Year Normal

NOWOOD RIVER 5               105               121              
GREYBULL RIVER 2               128               117              
SHELL CREEK 4               109               129              
BIGHORN (Boysen-Bighorn) 11               110               124              

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or Write:
D. Lee Hackleman, Water Supply Specialist
Natural Resources Conservation Service
100 East B Street
Casper, WY 82601
(307) 261-6481

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