Streamflow
Yields from 28 to 72 percent are expected in the basin during the forecast period. The following yields are based on the fifty
percent chance probability runoff for the April through September forecast period. The Sweetwater near Alcova is forecast to yield
about 21,000 acre-feet (28 percent of average). Deer Creek at Glenrock is expected to yield about 45 percent of average (17,500
acre-feet). LaPrele Creek above the reservoir is estimated to yield 44 percent of average (10,900 acre-feet). North Platte River
below Guernsey Reservoir is expected to yield about 46 percent of normal (445,000 acre-feet), and below Glendo Reservoir is
anticipated to yield about 47 percent of average (465,000 acre-feet). Laramie River near Woods should yield about 59 percent of
average (80,000 acre-feet). The Little Laramie near Filmore should produce about 46,000 acre-feet (72 percent of average).
================================================================================================================================== LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS 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) ====================================================================|=======================|===================================== Sweetwater River nr Alcova APR-JUL 6.9 11.7 | 18.0 26 | 35 59 69 APR-SEP 7.4 12.6 | 21 28 | 38 63 74 | | Deer Creek at Glenrock APR-SEP 3.9 10.8 | 17.5 45 | 26 41 39 | | La Prele Creek ab La Prele Reservoir APR-SEP 1.0 5.2 | 10.9 44 | 19.8 40 25 | | North Platte River blw Glendo APR-SEP 173 | 445 46 | 847 963 | | North Platte River blw Guernsey APR-SEP 178 | 465 47 | 880 989 | | Laramie River nr Woods APR-SEP 10.0 52 | 80 59 | 108 150 135 | | Little Laramie River nr Filmore APR-SEP 22 36 | 46 72 | 56 70 64 | | ================================================================================================================================== LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS | LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS 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 ========================================================================|========================================================= ALCOVA 184.3 156.8 156.5 153.1 | SWEETWATER 1 46 39 | GLENDO 506.4 276.4 347.8 276.4 | DEER & LaPRELE CREEKS 2 137 79 | GUERNSEY 45.6 10.5 14.3 5.5 | N PLATTE abv Laramie R. 16 91 64 | PATHFINDER 1016.5 928.9 869.8 505.0 | LARAMIE RIVER abv Laramie 3 68 59 | SEMINOE 1016.7 845.6 756.7 542.0 | LITTLE LARAMIE RIVER 1 81 47 | WHEATLAND #2 98.9 65.0 65.0 --- | LARAMIE RIVER above mouth 4 71 55 | NORTH PLATTE PROJ 1062.1 899.1 807.8 568.4 | NORTH PLATTE 17 87 63 | KENDRICK PROJECT 1201.7 993.6 982.9 819.8 | | GLENDO PROJECT USERS 183.2 155.6 156.5 116.2 | | ================================================================================================================================== * 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