UPPER MISSOURI BASIN
SEPTEMBER PRECIPITATION WAS BELOW AVERAGE ACROSS THE UPPER MISSOURI
BASIN. BASIN PRECIPITATION SUMMARIES FOR THE MISSOURI BASIN INCLUDE:
MILK ST. MARY, 35 PERCENT; MILK CANADA, 43 PERCENT; LOWER MILK, 36
PERCENT; ABOVE TOSTON, 54 PERCENT; TOSTON TO FT. PECK, 48 PERCENT.
OF THE FOUR MAJOR IRRIGATION RESERVOIRS IN MONTANA: LIMA RESERVOIR
HAD 106 PERCENT AVERAGE STORAGE, CLARK CANYON WAS HOLDING 120 PERCENT
OF AVERAGE WATER, GIBSON RESERVOIR HAD 19 PERCENT OF AVERAGE STORED
WATER, AND FRESNO RESERVOIR HAD 79 PERCENT OF AVERAGE STORED WATER.
THE MAJOR HYDROELECTRIC RESERVOIRS IN MONTANA (CANYON FERRY AND
FORT PECK) HAD MONTHEND STORAGE IN THE AVERAGE TO BELOW AVERAGE
RANGE; 100 AND 75 PERCENT OF AVERAGE WATER, RESPECTIVELY.
AS INDICATED BY THE U.S. GEOLOGICAL LONG TERM GAGING STATIONS,
THE MARIAS RIVER NEAR SHELBY, MONTANA HAD AN ESTIMATED 89 PERCENT
OF AVERAGE RUNOFF IN AUGUST.
YELLOWSTONE BASIN
PRECIPITATION DURING THE MONTH OF SEPTEMBER WAS ABOUT 45 PERCENT OF
AVERAGE IN THE WIND RIVER BASIN ABOVE BOYSEN RESERVOIR, 115 PERCENT
OF AVERAGE IN THE UPPER YELLOWSTONE BASIN, 39 PERCENT OF AVERAGE
IN THE BIGHORN BASIN, 43 PERCENT OF AVERAGE IN THE LITTLE BIGHORN-
-UPPER TONGUE BASINS, 50 PERCENT OF AVERAGE IN THE POWDER RIVER
BASIN, AND 29 PERCENT OF AVERAGE IN THE LOWER YELLOWSTONE BASIN.
MONTHEND STORAGE WAS 109 PERCENT OF AVERAGE AT BIGHORN RESERVOIR ON
THE WYOMING/MONTANA BORDER.
RUNOFF DURING SEPTEMBER 2009 IN THE YELLOWSTONE RIVER WAS 101 PERCENT OF
AVERAGE AT CORWIN SPRINGS AND 73 PERCENT OF AVERAGE AT BILLINGS, MONTANA.
PLATTE BASIN
PRECIPITATION DURING SEPTEMBER IN THE PLATTE BASIN WAS AVERAGE TO
BELOW AVERAGE. SEPTEMBER PRECIPITATION IN THE NORTH PLATTE BASIN
ABOVE SEMINOE RESERVOIR WAS 89 PERCENT OF AVERAGE. IN THE NORTH
PLATTE BASIN BETWEEN SEMINOE RESERVOIR AND GUERNSY RESERVOIR
PRECIPITATION WAS 79 PERCENT OF AVERAGE. THE NORTH PLATTE BASIN
BELOW GUERNSY RESERVOIR HAD 35 PERCENT OF AVERAGE PRECIPITATION.
THE HIGH ELEVATIONS OF THE SOUTH PLATTE BASIN HAD 109 PERCENT OF
AVERAGE SEPTEMBER PRECIPITATION WHEREAS THE PLAINS HAD 119 PERCENT
OF AVERAGE PRECIPITATION.
