Streamflow
Yields from 48 to 114 percent are expected in the basin during the forecast
period. The following yields are based on the fifty percent chance
probability runoff for the May through September forecast period. The
Sweetwater near Alcova is forecast to yield about 150,000 acre-feet (246
percent of average). Deer Creek at Glenrock is expected to yield about 103
percent of average (31,000 acre-feet). LaPrele Creek above the reservoir is
estimated to yield 110 percent of average (22,000 acre-feet). North Platte
River below Guernsey Reservoir is expected to yield about 94 percent of
normal (929,000 acre-feet), and below Glendo Reservoir is anticipated to
yield about 93 percent of average (892,000 acre-feet). Laramie River near
Woods should yield about 110 percent of average (140,000 acre-feet). The
Little Laramie near Filmore should produce about 61,000 acre-feet (100
percent of average).
================================================================================================================================== LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS Streamflow Forecasts - May 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) ====================================================================|=======================|===================================== Sweetwater River nr Alcova MAY-JUL 117 131 | 140 250 | 149 163 56 MAY-SEP 125 140 | 150 246 | 160 175 61 | | Deer Creek at Glenrock MAY-SEP 23 28 | 31 103 | 35 41 30 | | La Prele Creek ab La Prele Reservoir MAY-SEP 8.3 15.4 | 22 110 | 30 46 20 | | North Platte River blw Glendo APR-SEP 847 | 892 93 | 1396 963 | | North Platte River blw Guernsey APR-SEP 880 | 929 94 | 1444 989 | | Laramie River nr Woods MAY-SEP 95 122 | 140 110 | 158 185 127 | | Little Laramie River nr Filmore MAY-SEP 52 57 | 61 100 | 65 71 61 | | ================================================================================================================================== LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS | LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS Reservoir Storage (1000 AF) - End of April | Watershed Snowpack Analysis - May 1, 1999 ================================================================================================================================== Usable | *** Usable Storage *** | Number This Year as % of Reservoir Capacity| This Last | Watershed of ================= | Year Year Avg | Data Sites Last Yr Average ========================================================================|========================================================= ALCOVA 184.3 179.0 179.6 179.9 | SWEETWATER 3 158 137 | GLENDO 506.4 527.7 473.7 457.6 | DEER & LaPRELE CREEKS 4 170 130 | GUERNSEY 45.6 37.2 31.7 32.8 | N PLATTE abv Laramie R. 27 124 107 | PATHFINDER 1016.5 995.3 982.3 609.0 | LARAMIE RIVER abv Laramie 9 112 100 | SEMINOE 1016.7 719.8 690.4 392.0 | LITTLE LARAMIE RIVER 4 112 101 | WHEATLAND #2 98.9 76.0 79.0 54.9 | LARAMIE RIVER above mouth 12 111 100 | NORTH PLATTE PROJ 1062.1 1061.8 1102.6 786.7 | NORTH PLATTE 35 122 108 | KENDRICK PROJECT 1201.7 1031.3 959.3 807.0 | | GLENDO PROJECT USERS 183.2 172.2 167.0 128.9 | | ================================================================================================================================== * 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.