Wyoming Water Supply Outlook Report
February 1997

General
Water conditions across Wyoming are very good. January precipitation varied from normal to much above normal. Snowpack in all the basins is above average for this time of year. Precipitation for the year is good across the state with all areas above average. Reservoir storage is looking very good across the state also. There should be no water shortages this year, if the current trend continues.

Snowpack
Snowpack over the State is above normal for this time of the year. The Powder Tongue is currently the lowest basin in percent of average SWE at 124 percent. All the other basins go up from there to a high in the Belle Fourche and Cheyenne of 190 percent of average. SWE is well ahead of last year at this time. January snow water equivalent (SWE), compared to last year, varies from 16 to 80 percent more than last year.

Precipitation
Basins in the state received above average precipitation during the month. The higher altitude sites have generally received above normal precipitation. The Powder and Tongue River basin received the lowest precipitation in the state so far this water year (Oct - Sep). The entire State has above normal year-to-date precipitation. The extremes are Powder - Tongue (21% above average) and Shoshone and Belle Fourche Basins (86% above normal). 

Basin                 Departure      Basin                          Departure
                      from normal                                   from normal
 Snake River             +55%        Upper North Platte River          +48%
Yellowstone & Madison    +77%        Lower North Platte                +54%
Wind River               +50%        Little Snake River                +39%
Big Horn                 +27%        Upper Green River                 +39%
Shoshone & Clarks Fork   +86%        Lower Green River                 +55%
Powder & Tongue River    +21%        Upper Bear River                  +68%
Belle Fourche & Cheyenne +77%
Streams
All basins in the state should see average or above average runoff -- in some cases there will be much above average yield if the present trend continues. Record swe is being recorded in some portions of the state; high runoff might be expected in those portions of Wyoming. Under the right conditions exceptionally high flows could occur in the areas with record snow levels. Water users should not expect any shortages during the irrigation season. The only basin that could see flows close to average is the Powder-Tongue River basin.

Reservoirs
Generally speaking, reservoir storage is above average in the state with almost all reservoirs holding more than average amounts. Most reservoirs should fill to capacity this year. Even the reservoirs that appear to be low should fill. Some reservoirs are currently being drawn down in anticipation of excessive flows during the runoff season. See following table for further information about reservoir storage. 

                          B A S I N    W I D E
                     R E S E R V O I R    S U M M A R Y

                       FOR THE END OF JANUARY  1997


BASIN AREA         CURRENT AS  LAST YR AS  AVERAGE AS  CURRENT AS  CURRENT AS
 RESERVOIR         % CAPACITY  % CAPACITY  % CAPACITY   % AVERAGE   % LAST YR
-------------------------------------------------------------------------------
 ALCOVA                    85          85          85         100          99
 ANGOSTURA                 77          76          80          96         102
 BELLE FOURCHE             87          92          57         154          95
 BIG SANDY                                 NO REPORT
 BIGHORN LAKE              61          63          62          98          97
 BOYSEN                    91          96          97          93          95
 BUFFALO BILL              79          81          64         123          98
 BULL LAKE                 53          65          57          93          81
 DEERFIELD                 99          97          84         117         102
 EDEN                                      NO REPORT
 ENNIS LAKE                70          74          83          85          95
 FONTENELLE                43          48          57          76          91
 GLENDO                    62          53          65          95         117
 GRASSY LAKE               86          86          71         121         100
 GUERNSEY                  33          40          15         221          82
 HEBGEN LAKE               69          67          65         105         103
 JACKSON LAKE              82          80          57         144         102
 KEYHOLE                   76          56          51         150         136
 PACTOLA                   97         102          83         117          96
 PALISADES                 85          98          75         114          87
 PATHFINDER                85          71          54         156         119
 PILOT BUTTE               75          70          52         143         107
 SEMINOE                   70          77          46         151          90
 SHADEHILL                 50          50          60          82          99
 TONGUE RIVER                              NO REPORT
 VIVA NAUGHTON RES         64          79          68          94          81
 WHEATLAND #2              52          66          41         127          78
 WOODRUFF NARROWS                          NO REPORT


 GLENDO PROJECT USERS      82          86          65         125          95
 KENDRICK PROJECT          82          54          68         120         150
 NORTH PLATTE PROJ         72          93          57         127          78
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