Water Supply Statement for the Missouri River Basin issued for September 2017

Missouri Basin River Forecast Center
Water Supply Statement
Issued in cooperation with the Natural
Resources Conservation Service
Issued:  October 16, 2017

UPPER MISSOURI BASIN

SEPTEMBER PRECIPITATION RANGED FROM BELOW TO ABOVE AVERAGE ACROSS THE 
UPPER MISSOURI BASIN.  BASIN PRECIPITATION SUMMARIES FOR THE MISSOURI 
BASIN INCLUDE: MILK ST. MARY, 38 PERCENT; MILK CANADA, 36 PERCENT; 
LOWER MILK, 101 PERCENT; ABOVE TOSTON, 218 PERCENT; TOSTON TO 
FT. PECK, 156 PERCENT.

OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA:  LIMA RESERVOIR
HAD 150 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 105 PERCENT OF
AVERAGE WATER, GIBSON RESERVOIR HAD 24 PERCENT OF AVERAGE STORED
WATER, AND FRESNO RESERVOIR HAD 94 PERCENT OF AVERAGE STORED WATER.
THE  MAJOR  HYDROELECTRIC  RESERVOIRS  IN  MONTANA (CANYON  FERRY AND
FORT PECK) HAD MONTHEND STORAGE IN THE ABOVE AVERAGE RANGE; 96 AND
115 PERCENT OF AVERAGE WATER, RESPECTIVELY.

YELLOWSTONE BASIN

PRECIPITATION DURING THE MONTH OF SEPTEMBER WAS ABOUT 210 PERCENT OF
AVERAGE IN THE WIND RIVER BASIN ABOVE BOYSEN RESERVOIR, 260 PERCENT
OF AVERAGE IN THE UPPER YELLOWSTONE BASIN, 225 PERCENT OF AVERAGE
IN THE BIGHORN BASIN, AND 156 PERCENT OF AVERAGE IN THE LITTLE
BIGHORN BASINS-UPPER TONGUE BASINS, 174 PERCENT OF AVERAGE IN THE
POWDER RIVER BASIN, AND 193 PERCENT OF AVERAGE IN THE LOWER
YELLOWSTONE BASIN.

MONTHEND STORAGE WAS 107 PERCENT OF AVERAGE AT BIGHORN RESERVOIR ON
THE WYOMING/MONTANA BORDER.
 

PLATTE BASIN

PRECIPITATION DURING SEPTEMBER IN THE PLATTE BASIN WAS ABOVE
AVERAGE. SEPTEMBER PRECIPITATION IN THE NORTH PLATTE BASIN
ABOVE SEMINOE RESERVOIR WAS 129 PERCENT OF AVERAGE. IN THE
NORTH PLATTE BASIN BETWEEN SEMINOE RESERVOIR AND GUERNSY
RESERVOIR PRECIPITATION WAS 117 PERCENT OF AVERAGE. THE NORTH
PLATTE BASIN BELOW GUERNSY RESERVOIR HAD 96 PERCENT OF AVERAGE
PRECIPITATION. THE HIGH ELEVATIONS OF THE SOUTH PLATTE BASIN HAD
143 PERCENT OF AVERAGE SEPTEMBER PRECIPITATION WHEREAS THE PLAINS
HAD 129 PERCENT OF AVERAGE PRECIPITATION.

STORED WATER IN THE SOUTH PLATTE BASIN STORED WATER WAS 117 PERCENT
OF AVERAGE.

PRECIPITATION MAPS

September 2017	WY 2017
September 2017 Precipitation Percent of 1981-2010 Average	WY2017 Precipitation as Percent of 1981-2010 Average
September 2017 Basin Mean Precipitation	WY2017 Basin Mean Precipitation
September 2017 MBRFC Basin Mean Precipitation	WY2017 MBRFC Basin Mean Precipitation