Wyoming Water Supply Outlook Report
April 2000

General
Generally, snow water equivalent (SWE) across the state is slightly below normal. SWE is about 10 percent below average for most of the State -- north portion of the State is 85 percent of normal and south part of the State is 91 percent of average. Precipitation for March was below average for March, but the year-to-date precipitation is average to below average. The Shoshone River drainage year-to-date precipitation is near average and the remaining portion of the state is 10-30 percent below average. Most of the reservoir levels are average to well above average. Forecast runoff varies, but is generally from 45 to 100 percent of average. The mean of all the forecast points in the State is about 25 percent below average. The minimum yield forecast was 46 percent of average in the Middle Fork of the Powder River near Barnum and the maximum forecast was 104 percent of average at North Platte near Northgate.

Snowpack
Snow conditions stayed nearly the same as last month across the State, but SWE is generally just below average. SWE in the northwestern portion of the State remained almost the same as last month at 86 percent of average. Northeast Wyoming SWE is running slightly less at about 84 percent of average. The Southeast portion saw a slight increase to 89 percent of average SWE. And the southwest remained about the same with 88 percent of average.

Precipitation
March precipitation was below normal across the state. The following table displays the major river basins and their departure from normal for March 2000.

BasinDeparture
from normal		BasinDeparture
from normal
Snake River -14%Upper North Platte River-12%
Yellowstone & Madison +02%Lower North Platte River-17%
Wind River -09%Little Snake River -21%
Bighorn -19%Upper Green River -22%
Shoshone & Clarks Fork -28%Lower Green River -27%
Powder & Tongue River -19%Upper Bear River -09%
Belle Fourche & Cheyenne-35%

Streams
Stream flow yield is expected to be below average across the State. The northwest part of the State is expected to yield about 75-80 percent of normal -- yield estimates vary from 49 to 91 percent of normal through the northwest region of the State. Yield from the northeast portion of Wyoming will be below average (about 70 percent of average) -- yield estimates vary from 46 to 87 percent of average for the various forecast points. In most cases, the southeast portion of the state will be about 77 percent of normal -- yield estimates range from 55 to 104 percent of normal. The southwest portion of Wyoming varies from 64 to 96 percent of average -- mean estimated yield for the forecast points in southwest Wyoming is about 81 percent of average.


Reservoirs
Although several reservoirs did not report, reservoir storage for those reporting is generally above average for this time of the year. See following table for further information about reservoir storage.

Major Reservoirs in Wyoming

                             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  MARCH   2000


 BASIN AREA         CURRENT AS  LAST YR AS  AVERAGE AS  CURRENT AS  CURRENT AS
  RESERVOIR         % CAPACITY  % CAPACITY  % CAPACITY   % AVERAGE   % LAST YR
-------------------------------------------------------------------------------
ALCOVA                    85          88          88          97          97
ANGOSTURA                 99          99          90         109         100
BELLE FOURCHE            101         101          73         138         100
BIG SANDY                                 NO REPORT
BIGHORN LAKE              67          58          59         114         117
BOYSEN                    88          79          89          99         111
BUFFALO BILL              67          62          56         122         108
BULL LAKE                 63          64          55         114          98
DEERFIELD                 99         101          89         111          98
EDEN                                      NO REPORT
ENNIS LAKE                71          76          81          88          94
FLAMING GORGE                       AVERAGE NOT ESTABLISHED
FONTENELLE                30          36          46          67          86
GLENDO                    92         100          83         110          92
GRASSY LAKE               84          87          74         113          96
GUERNSEY                  41          66          47          86          62
HEBGEN LAKE               81          68          65         124         118
JACKSON LAKE              78          70          56         139         110
KEYHOLE                   90          94          56         162          96
PACTOLA                   98          98          85         116         100
PALISADES                 85          51          72         117         167
PATHFINDER                98          96          61         161         102
PILOT BUTTE               71          70          68         105         101
SEMINOE                   73          66          36         202         110
SHADEHILL                 69          94          78          89          73
TONGUE RIVER              54          18          53         102         300
VIVA NAUGHTON RES         79          70          64         123         112
WHEATLAND #2              75          67          49         152         112
WOODRUFF NARROWS                    AVERAGE NOT ESTABLISHED
GLENDO PROJECT USERS      85          92          69         122          92
KENDRICK PROJECT          82          81          68         121         101
NORTH PLATTE PROJ        100          94          64         158         107
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