Streamflow
The fifty-percent chance June through September runoff in the Lower North Platte River basin is forecast much below
average. Irrigators without a storage facility may experience water shortage. Yields from 34 to 73 percent are expected
in the basin during the forecast period. The following yields are based on the fifty percent chance probability runoff for
the June through September forecast period. The Sweetwater near Alcova is forecast to yield about 13,400 acre-feet (37
percent of average). Deer Creek at Glenrock is expected to yield about 63 percent of average (4,600 acre-feet). LaPrele
Creek above the reservoir is estimated to yield 34 percent of average (2,100 acre-feet). North Platte River below
Guernsey Reservoir is expected to yield about 48 percent of normal (230,000 acre-feet), and below Glendo Reservoir is
anticipated to yield about 47 percent of average (210,000 acre-feet). Laramie River near Woods should yield about 73
percent of average (65,000 acre-feet). The Little Laramie near Filmore should produce about 24,000 acre-feet (50
percent of average).
================================================================================================================================== LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS Streamflow Forecasts - June 1, 2001 ================================================================================================================================== | <<====== 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 JUN-JUL 8.3 9.8 | 10.8 35 | 14.9 21 31 JUN-SEP 11.0 12.4 | 13.4 37 | 16.7 22 36 | | Deer Creek at Glenrock JUN-SEP 1.80 3.31 | 4.60 63 | 6.10 8.70 7.25 | | La Prele Creek ab La Prele Reservoir JUN-SEP 0.46 1.24 | 2.10 34 | 3.28 5.71 6.20 | | North Platte River blw Glendo Reserv JUN-JUL 158 180 | 195 47 | 240 307 419 JUN-SEP 171 194 | 210 47 | 258 328 451 | | North Platte River blw Guernsey Resv JUN-JUL 163 191 | 210 49 | 264 344 433 JUN-SEP 179 209 | 230 48 | 289 377 479 | | Laramie River nr Woods JUN-SEP 36 53 | 65 73 | 77 94 89 | | Little Laramie River nr Filmore JUN-SEP 15.3 21 | 24 50 | 28 33 48 | | ================================================================================================================================== LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS | LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS Reservoir Storage (1000 AF) - End of May | Watershed Snowpack Analysis - June 1, 2001 ================================================================================================================================== Usable | *** Usable Storage *** | Number This Year as % of Reservoir Capacity| This Last | Watershed of ================= | Year Year Avg | Data Sites Last Yr Average ========================================================================|========================================================= ALCOVA 184.3 180.0 180.7 180.4 | SWEETWATER 1 0 0 | GLENDO 506.4 444.8 507.1 501.0 | DEER & LaPRELE CREEKS 2 0 0 | GUERNSEY 45.6 473.8 35.9 34.5 | N PLATTE abv Laramie R. 16 80 27 | PATHFINDER 1016.5 797.9 993.1 638.0 | LARAMIE RIVER abv Laramie 3 43 15 | SEMINOE 1016.7 751.1 914.2 551.0 | LITTLE LARAMIE RIVER 1 0 2 | WHEATLAND #2 98.9 61.0 81.0 54.6 | LARAMIE RIVER above mouth 4 44 11 | NORTH PLATTE PROJ NO REPORT | NORTH PLATTE 17 80 27 | KENDRICK PROJECT NO REPORT | | GLENDO PROJECT USERS NO REPORT | | ================================================================================================================================== * 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.