August’s hot weather keeps river flows low

August's hot weather keeps river flows low Continuing drought combined with court ordered release restrictions resulted in low flows on the Missouri River in August. Runoff above Sioux City, IA, was only 31 percent of normal.

"Hot dry weather during August produced only 400,000 acre feet of runoff, the second lowest in 106 years of record keeping. Parts of the basin received little or no rain. Inflows into Garrison were only 14 percent of normal," said Larry Cieslik, chief of the Missouri River Water Management Division in Omaha.

Recent court action required Gavins Point releases be reduced to comply with the Biological Opinion published by the U.S. Fish and Wildlife Service in November 2000. "The reduced releases were not sufficient to meet minimum service flow targets from Nebraska City to the mouth," said Cieslik.

"Flow restrictions required by the biological opinion ended on Sept. 1, allowing us to increase releases to meet minimum service levels," he said. The releases were gradually increased from 25,000 cfs to 30,500 cfs. They will vary as necessary to meet downstream targets for the remainder of the navigation season. The season will be shortened six days to make up for the additional water released last winter for downstream water intakes. It will end at the mouth near St. Louis on Nov. 25.

Releases from Tuttle Creek Reservoir in Kansas will be increased in mid-September to supplement flows on the Missouri River from Kansas City to the mouth. Additional releases from Milford and Perry reservoirs are being coordinated with the state of Kansas. The current release rate from the Kansas projects is 1,000 cfs for water quality. Current plans call for an increase to 2,000 cfs, but may change depending on localized rain.

The runoff forecast for 2003 has been reduced to 18.5 million acre feet (MAF). Normal annual runoff is 25.2 mAF.

System storage ended August at 42.9 MAF, a record low for that date. The previous record was 44 MAF in 1990. Last year at this time it was 46.9 MAF. The amount of water currently stored in the reservoirs is nearly 17 MAF below average.

Three pubic meetings to review the draft 2003-2004 Annual Operating Plan for the Missouri River will be held next month. The first will be on Tuesday, Oct. 28 in Pierre. The second will be on Wednesday, Oct. 29 in Omaha, NE. The third will be on Thursday, Oct. 30 in Columbia, MO. Sites and times will be announced in the coming weeks.

Gavins Point releases averaged 24,900 cfs in August, compared to the long-term average of 36,300 cfs. Lewis and Clark Lake will gradually rise to elevation 1207.5 feet msl during September.

Fort Randall releases averaged 24,500 cfs in August. In September, they will range from 28,000 to 31,000 cfs as needed to maintain Lewis and Clark Lake near its desired elevation. Lake Francis Case ended the month at 1353.8 feet msl. It will remain near that level through most of September before beginning its annual drawdown. The lake will end October near elevation 1345 feet msl.

Lake Oahe dropped two feet during August, ending he month at elevation 1584.4 feet msl. It will drop more than three feet during September, ending the month 22 feet below normal. The reservoir is four feet lower than last year at this time.

Garrison releases averaged 21,100 cfs during August. They were reduced to 19,500 cfs on Sept. 3, and will be held at that rate until Sept. 14 and then gradually reduced to 10,000 cfs by Sept. 17.

Lake Sakakawea fell three feet in August, ending the month at 1822.9 feet msl. It will drop less than two feet in September, ending the month nearly 18 feet below normal. The lake is six feet lower than last year at this time.

Fort Peck releases averaged 7,100 cfs in August. The lake dropped more than one foot in August, ending the month at elevation 2201.8 feet msl.

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