Streamflow
The 50 percent chance April through September runoff is anticipated to be well below normal. The Wind River at Boysen is
forecast to yield 525,000 acre feet (65 percent of average); the Nowood River near Ten Sleep should yield near 22,000 acre feet
(38 percent of normal); the Greybull River at Meeteese should yield 100,000 acre feet (50 percent of average); Shell Creek near
Shell should yield 65,000 acre feet (87 percent of average) and the Bighorn River at Kane should yield 726,000 acre feet (65
percent of average).
================================================================================================================================== BIGHORN RIVER BASIN Streamflow Forecasts - January 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) ====================================================================|=======================|===================================== BOYSEN RESERVOIR Inflow (2) APR-SEP 173 383 | 525 65 | 667 877 809 | | NOWOOD RIVER nr Tensleep (D) APR-SEP 2.3 9.3 | 22 38 | 35 53 58 | | GREYBULL RIVER nr Meeteetse APR-SEP 68 87 | 100 50 | 113 132 201 | | SHELL CREEK nr Shell APR-SEP 54 61 | 65 87 | 69 76 75 | | BIGHORN RIVER at Kane (2) APR-SEP 281 520 | 726 65 | 932 1169 1124 | | ================================================================================================================================== BIGHORN RIVER BASIN | BIGHORN RIVER BASIN Reservoir Storage (1000 AF) - End of December | Watershed Snowpack Analysis - January 1, 2000 ================================================================================================================================== Usable | *** Usable Storage *** | Number This Year as % of Reservoir Capacity| This Last | Watershed of ================= | Year Year Avg | Data Sites Last Yr Average ========================================================================|========================================================= BOYSEN 596.0 547.0 593.1 613.5 | NOWOOD RIVER 2 110 82 | BIGHORN LAKE 1356.0 960.3 944.1 891.8 | GREYBULL RIVER 2 30 38 | | SHELL CREEK 3 106 93 | | BIGHORN (Boysen-Bighorn) 7 88 81 | ================================================================================================================================== * 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. (3) - Forecasts produced in cooperation with Alberta Forecasting Staff Canada