Streamflow
The following runoff values are for the 50 percent probability during
the April through September forecast period. The estimated yield for
Tongue River near Dayton is 97,000 acre-feet (84 percent of normal).
Water users on the Middle Fork near Barnum should have a yield near
16,800 acre-feet (85 percent of normal). The North Fork of the Powder
near Hazelton should yield about 9,300 acre-feet (92 percent of
normal). The estimated yield for Clear Creek near Buffalo is 34,000
acre-feet (87 percent of average). Rock Creek near Buffalo will yield
about 19,000 acre-feet (79 percent of normal), and Piney Creek at
Kearny should yield about 43,000 acre-feet (84 percent of average).
================================================================================================================================== POWDER & TONGUE RIVER BASINS Streamflow Forecasts - April 1, 1999 ================================================================================================================================== | <<====== 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) ====================================================================|=======================|===================================== TONGUE RIVER nr Dayton (2) APR-SEP 69 86 | 97 84 | 108 125 115 | | MIDDLE FORK POWDER nr Barnum APR-SEP 9.7 13.9 | 16.8 85 | 19.7 24 19.7 | | NORTH FORK POWDER nr Hazelton APR-SEP 6.7 8.2 | 9.3 92 | 10.4 11.9 10.1 | | CLEAR CREEK nr Buffalo APR-SEP 25 31 | 34 87 | 38 43 39 | | ROCK CREEK nr Buffalo APR-SEP 12.2 16.2 | 19.0 79 | 22 26 24 | | PINEY CREEK at Kearny APR-SEP 17.3 33 | 43 84 | 53 69 51 | | ================================================================================================================================== POWDER & TONGUE RIVER BASINS | POWDER & TONGUE RIVER BASINS Reservoir Storage (1000 AF) - End of March | Watershed Snowpack Analysis - April 1, 1999 ================================================================================================================================== Usable | *** Usable Storage *** | Number This Year as % of Reservoir Capacity| This Last | Watershed of ================= | Year Year Avg | Data Sites Last Yr Average ========================================================================|========================================================= TONGUE RIVER 68.0 12.3 9.5 36.1 | UPPER TONGUE RIVER 9 92 84 | | GOOSE CREEK 3 86 77 | | CLEAR CREEK 4 80 80 | | CRAZY WOMAN CREEK 3 87 83 | | UPPER POWDER RIVER 4 93 85 | | POWDER RIVER in WY 8 87 83 | ================================================================================================================================== * 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. (D) - The operational measurement of flow at this point has been discountinued.