Precipitation
Reservoirs
Streamflow
The entire drainage basin is expected to have below average runoff. All the following yields are based on the
fifty percent chance April through September yield. Yield for the North Platte River near the Colorado state line
is expected to be 195,000 acre feet (72 percent of average). Encampment River near Encampment is estimated to
yield 103,000 acre feet (66 percent of normal). North Platte River near Sinclair will yield about 490,000 acre feet
(about 68 percent of normal). Rock Creek near Arlington is estimated to yield 47,000 acre feet (about 84 percent
of average). Medicine Bow River above Seminoe Reservoir is expected to yield about 76,000 acre feet (about 60
percent of normal). Seminoe Reservoir inflow should be about (575,000 acre feet (68 percent of normal). See
the following table for more detailed information on projected runoff.
================================================================================================================================== UPPER NORTH PLATTE RIVER BASIN Streamflow Forecasts - June 1, 1998 ================================================================================================================================== | <<====== 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) ====================================================================|=======================|===================================== North Platte River nr Northgate JUN-SEP 55 77 | 92 58 | 107 129 158 | | Encampment River nr Encampment JUN-SEP 62 80 | 93 90 | 106 124 103 | | North Platte River nr Sinclair JUN-SEP 198 262 | 305 71 | 348 412 431 | | Rock Creek nr Arlington JUN-SEP 28 30 | 31 74 | 33 35 42 | | Medicine Bow River ab Seminoe Reserv JUN-SEP 16.4 24 | 29 45 | 35 45 64 | | Seminoe Reservoir Inflow JUN-JUL 184 247 | 290 68 | 333 396 428 JUN-SEP 156 260 | 330 67 | 400 504 491 | | ================================================================================================================================== UPPER NORTH PLATTE RIVER BASIN | UPPER NORTH PLATTE RIVER BASIN Reservoir Storage (1000 AF) - End of May | Watershed Snowpack Analysis - June 1, 1998 ================================================================================================================================== Usable | *** Usable Storage *** | Number This Year as % of Reservoir Capacity| This Last | Watershed of ================= | Year Year Avg | Data Sites Last Yr Average ========================================================================|========================================================= SEMINOE 1016.7 777.2 785.4 551.0 | N PLATTE above Northgate 5 49 65 | | ENCAMPMENT RIVER 3 56 91 | | BRUSH CREEK 2 75 94 | | MEDICINE BOW & ROCK CREEK 2 43 58 | | N PLATTE above Seminoe 13 52 73 | ================================================================================================================================== * 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.