Lower North Platte River Basin (9)
February 2002

Snow
SWE for the North Platte River basin in Wyoming averages 57 percent of normal (75 % of last year). The Sweetwater drainage SWE is currently 74 percent of average (133 percent of last year). Deer and LaPrele Creek SWE is 44 percent of average (43 percent of last year. SWE for the North Platte above the Laramie River drainage is 61 percent of average (80 % of last year). SWE for the Laramie River above the mouth is 46 percent of average (64 % of last year). SWE for the Laramie River above Laramie is 49 percent of average (66 % of last year). SWE for the Little Laramie River is 39 percent of average (58 percent of last year). For more information see Basin Summary of Snow Courses at beginning of report.

Precipitation
Of the 14 reporting stations, percentages for the month range from 0 to 112. January precipitation for the basin was 49 percent of average (134 percent of last year). The water year-to-date precipitation for the basin is currently 72 percent of average (99 percent of last year). Year to date percentages range from 58 to 130.

Reservoir
The Lower North Platte River basin reservoir storage is well below to well above average. Reservoir storage is as follows: Alcova 156,800 acre feet (101 percent of average); Glendo 283,000 acre feet (85 percent of average); Guernsey 13,200 acre feet (145 percent of average); Pathfinder 502,700 acre feet (74 percent of average); Seminoe 480,000 acre feet (84 percent of average). Wheatland No.2 19,000 acre feet (42 percent of average). Water allocated to project use is near average with North Platte Project users at 48 percent of average, Kendrick Project users at 101 percent of average, and Glendo Project users at 112 percent of average.

Streamflow
Yields from 17 to 58 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 38,000 acre-feet (48 percent of average). Deer Creek at Glenrock is expected to yield about 17 percent of average (7,000 acre-feet). LaPrele Creek above the reservoir is estimated to yield 17 percent of average (4,000 acre-feet). North Platte River below Guernsey Reservoir is expected to yield about 39 percent of normal (398,000 acre-feet), and below Glendo Reservoir is anticipated to yield about 40 percent of average (392,000 acre-feet). Laramie River near Woods should yield about 58 percent of average (78,000 acre-feet). The Little Laramie near Filmore should produce about 27,000 acre-feet (42 percent of average). 

==================================================================================================================================
                                      LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS
                                               Streamflow Forecasts - February 1, 2002
==================================================================================================================================
                                              |  <<====== 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      13.6        26    |       35        47    |        53        81             74
                                     APR-SEP      15.3        29    |       38        48    |        57        85             80
                                                                    |                       |
Deer Creek at Glenrock               APR-SEP       2.7       4.8    |      7.0        17    |      12.3        23             41
                                                                    |                       |
La Prele Creek ab La Prele Reservoir APR-SEP       1.0       1.8    |      4.0        17    |       8.5      19.7             24
                                                                    |                       |
Alcova to Orin Gain                  APR-JUL       4.0       9.0    |     12.0         8    |        50       107            152
                                     APR-SEP       5.0      10.0    |     13.0         8    |        52       110            161
                                                                    |                       |
North Platte River blw Glendo Reserv APR-JUL       281       345    |      389        41    |       496       652            960
                                     APR-SEP       281       347    |      392        40    |       504       670            990
                                                                    |                       |
North Platte River blw Guernsey Resv APR-JUL       254       330    |      382        39    |       515       710            970
                                     APR-SEP       265       344    |      398        39    |       536       738           1010
                                                                    |                       |
Laramie River nr Woods               APR-SEP        40        62    |       78        58    |       105       144            135
                                                                    |                       |
Little Laramie River nr Filmore      APR-SEP      18.3        24    |       27        42    |        35        48             64
                                                                    |                       |
==================================================================================================================================
          LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS         |  LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS
             Reservoir Storage (1000 AF) - End of January               |        Watershed Snowpack Analysis - February 1, 2002
==================================================================================================================================
                                      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    156.6    155.0 |   SWEETWATER                  3       133        74
                                                                        |
GLENDO                                 506.4    283.0    283.5    334.9 |   DEER & LaPRELE CREEKS       3        43        44
                                                                        |
GUERNSEY                                45.6     13.2     12.8      9.1 |   N PLATTE abv Laramie R.    25        80        62
                                                                        |
PATHFINDER                            1016.5    502.7    728.1    678.3 |   LARAMIE RIVER abv Laramie   8        66        49
                                                                        |
SEMINOE                               1016.7    480.0    680.9    573.2 |   LITTLE LARAMIE RIVER        4        58        39
                                                                        |
WHEATLAND #2                            98.9     19.0     34.0     45.3 |   LARAMIE RIVER above mouth  11        64        46
                                                                        |
NORTH PLATTE PROJ                     1062.1    286.6    584.9    601.0 |   NORTH PLATTE               31        76        58
                                                                        |
KENDRICK PROJECT                      1201.7    828.6    971.2    819.1 |
                                                                        |
GLENDO PROJECT USERS                   183.2    134.5    136.3    119.8 |
                                                                        |
==================================================================================================================================
 * 90%, 70%, 30%, and 10% chances of exceeding are the probabilities that the actual volume will exceed the volumes in the table.

(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.
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