Precipitation
Reservoir
Streamflow
The fifty percent yield (April through September period) for North Fork
Shoshone River at Wapiti is expected to be 440,000 acre-feet (85 percent of
average). South Fork of the Shoshone River near Valley is estimated to
yield of 175,000 acre-feet (65 percent of average), and South Fork above
Buffalo Bill Reservoir is expected to be 112,000 acre-feet (49 percent of
average). At the Buffalo Bill Reservoir, the fifty percent chance yield
for the Shoshone River is expected to be about 555,000 acre-feet (69
percent of average). The fifty-percent chance yield for the Clarks Fork of
the Yellowstone near Belfry, Montana is expected to be about 535,000 acre-
feet (91 percent of average).
================================================================================================================================== SHOSHONE & CLARKS FORK RIVER BASINS Streamflow Forecasts - April 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) ====================================================================|=======================|===================================== NF SHOSHONE RIVER at Wapiti APR-SEP 373 413 | 440 85 | 467 507 520 | | SF SHOSHONE RIVER nr Valley APR-SEP 129 156 | 175 65 | 194 221 269 | | SF SHOSHONE RIVER abv Buffalo Bill APR-SEP 35 81 | 112 49 | 143 189 229 | | BUFFALO BILL DAM Inflow (2) APR-SEP 403 493 | 555 69 | 617 707 804 | | CLARKS FORK RIVER nr Belfry APR-SEP 446 499 | 535 91 | 571 624 590 | | ================================================================================================================================== SHOSHONE & CLARKS FORK RIVER BASINS | SHOSHONE & CLARKS FORK RIVER BASINS Reservoir Storage (1000 AF) - End of March | Watershed Snowpack Analysis - April 1, 2000 ================================================================================================================================== Usable | *** Usable Storage *** | Number This Year as % of Reservoir Capacity| This Last | Watershed of ================= | Year Year Avg | Data Sites Last Yr Average ========================================================================|========================================================= BUFFALO BILL 646.6 436.2 402.7 359.0 | SHOSHONE RIVER 7 71 86 | | CLARKS FORK in WY 7 81 91 | ================================================================================================================================== * 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.