Streamflow
The most probable, 50 percent chance, May through September runoff yield forecast is below average for the basin. The Snake near Moran is expected to yield 642,000 acre-feet (79 percent of normal). Yield from the Snake River above Palisades Reservoir is estimated to be 1,930,000 acre-feet (78 percent of normal). The 50 percent chance yield near Heise is expected to be 2,840,000 acre-feet (77 percent of normal). Pacific Creek at Moran is expected to yield about 117,000 acre-feet (75 percent of average). Greys River above Palisades Reservoir is estimated to yield 231,000 acre-feet (66 percent of normal). Salt River near Etna is estimated to have a yield of 217,000 acre-feet (64 percent of normal).
================================================================================================================================== SNAKE RIVER BASIN Streamflow Forecasts - May 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) ====================================================================|=======================|===================================== SNAKE near Moran (1,2) MAY-SEP 515 602 | 642 79 | 682 769 814 | | SNAKE above Palisades (2) MAY-SEP 1694 1835 | 1930 78 | 2025 2166 2475 | | SNAKE near Heise (2) MAY-SEP 2451 2682 | 2840 77 | 2998 3229 3672 | | PACIFIC CREEK at Moran MAY-SEP 89 106 | 117 75 | 128 145 157 | | GREYS above Palisades MAY-SEP 191 215 | 231 66 | 247 271 350 | | SALT near Etna MAY-SEP 154 192 | 217 64 | 242 280 339 | | ================================================================================================================================== SNAKE RIVER BASIN | SNAKE RIVER BASIN Reservoir Storage (1000 AF) - End of April | Watershed Snowpack Analysis - May 1, 2000 ================================================================================================================================== Usable | *** Usable Storage *** | Number This Year as % of Reservoir Capacity| This Last | Watershed of ================= | Year Year Avg | Data Sites Last Yr Average ========================================================================|========================================================= GRASSY LAKE 15.2 13.0 13.4 11.7 | SNAKE above Jackson Lake 6 45 54 | JACKSON LAKE 847.0 716.6 533.1 456.5 | PACIFIC CREEK 2 45 64 | PALISADES 1400.0 1161.1 555.4 950.0 | GROS VENTRE RIVER 4 54 59 | | HOBACK RIVER 6 48 63 | | GREYS RIVER 5 57 67 | | SALT RIVER 5 50 55 | | SNAKE above Palisades 25 48 57 | ================================================================================================================================== * 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.