Lower North Platte River Basin
March 1997

Snow
Higher than normal snowfall across the basin has caused near record snow water equivalent (SWE). Deer and LaPrele Creeks are currently at 166 percent of average. The Sweetwater drainage is 140 percent. The North Platte above the Laramie river drainage is 41 percent above average. The basin average SWE is now 139 percent of normal. This is 16 percent ahead of what it was last year at this time. For more information see Basin Summary of Snow Courses at beginning of report.

Precipitation
February precipitation in the basin varied quite a lot. Of the reporting stations, Christina Lake came in with 21 percent of average precipitation for the month, while Douglas Aviation reported 465 percent of the February average. Three stations reported over 200 percent for the month. February precipitation for the basin was 85 percent of average (181 percent of last year). The water year-to-date precipitation for the basin is currently 136 percent of average (22 percent ahead of last year).

Reservoir
Basin Reservoir storage is in good shape. Storage at all of the reservoirs is near average to well above average. Reservoir storage is as follows: Alcova 158,000 acre feet (101 percent of average), Glendo 373,300 acre feet (97 percent of average), Guernsey 17,900 acre feet (132 percent of normal), Pathfinder 889,000 acre feet (151 percent of average), Seminoe 671,700 acre feet (164 percent of average), and Wheatland No. Two 55,000 acre feet (127 percent of average).

Streamflow
At this time, above average yields are expected over the entire basin during the April to September forecast period. All the following values are based on the fifty percent chance probability runoff. The highest forecast is the Deer Creek drainage at 205 percent of average (80,000 acre feet). Below Guernsey, the North Platte River should flow near 141 percent of average (1,390,000 acre feet). The Sweetwater is forecast to flow 118,000 acre feet (162 percent of average). LaPrele Creek should yield 172 percent of average (43,000 acre feet). North Platte below Glendo should yield about 139 percent of average (1,340,000 acre feet). Laramie River near Woods should yield about 126 percent of average (170,000 acre feet). The Little Laramie near Filmore should flow 85,000 acre feet (133 percent of average). 

==================================================================================================================================
                                      LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS
                                               Streamflow Forecasts - March 1, 1997
==================================================================================================================================
                                              |  <<====== 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)
====================================================================|=======================|=====================================
SEMINOE RESERVOIR INFLOW             APR-JUL       934      1086    |     1190       149    |      1294      1446            800
                                                                    |                       |
SWEETWATER RIVER nr Alcova           APR-JUL        82        91    |      110       159    |       131       138             69
                                     APR-SEP        87        99    |      118       162    |       137       146             73
                                                                    |                       |
DEER CREEK at Glenrock               APR-SEP        51        68    |       80       205    |        92       109             39
                                                                    |                       |
LaPRELE CREEK above Reservoir        APR-SEP        28        37    |       43       172    |        49        58             25
                                                                    |                       |
NORTH PLATTE RIVER blw Glendo        APR-SEP      1002              |     1340       139    |                1695            963
                                                                    |                       |
NORTH PLATTE R. blw Guernsey         APR-SEP      1038              |     1390       141    |                1760            989
                                                                    |                       |
LARAMIE RIVER near Woods             APR-SEP       115       148    |      170       126    |       192       225            135
                                                                    |                       |
LITTLE LARAMIE RIVER near Filmore    APR-SEP        64        76    |       85       133    |        94       106             64
                                                                    |                       |
==================================================================================================================================
          LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS         |  LOWER NORTH PLATTE, SWEETWATER & LARAMIE RIVER BASINS
             Reservoir Storage (1000 AF) - End of February              |        Watershed Snowpack Analysis - March 1, 1997
==================================================================================================================================
                                      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    158.0    156.3    157.1 |   SWEETWATER                  4       132       140
                                                                        |
GLENDO                                 506.4    373.3    315.8    383.1 |   DEER & LaPRELE CREEKS       4       151       166
                                                                        |
GUERNSEY                                45.6     17.9     21.3     13.6 |   N PLATTE abv Laramie R.    28       118       141
                                                                        |
PATHFINDER                            1016.5    889.0    783.3    590.0 |   LARAMIE RIVER abv Laramie   8        94       121
                                                                        |
SEMINOE                               1016.7    671.7    732.5    409.0 |   LITTLE LARAMIE RIVER        4       119       137
                                                                        |
WHEATLAND #2                            98.9     55.0     64.8     43.2 |   LARAMIE RIVER above mouth  11       102       127
                                                                        |
NORTH PLATTE PROJ                     1062.1    811.3   1032.7    633.3 |   NORTH PLATTE               35       116       139
                                                                        |
KENDRICK PROJECT                      1201.7    979.8    652.3    818.1 |
                                                                        |
GLENDO PROJECT USERS                   183.2    160.0    164.5    126.8 |
                                                                        |
==================================================================================================================================
 * 90%, 70%, 30%, and 10% chances of exceeding are the probabilities that the actual flow will exceed the volumes in the table.

The average is computed for the 1961-1990 base period.
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