Reservoir storage at record low

Reservoir storage at record low Drought conditions persist over much of the Missouri River basin, dropping storage in the six reservoirs to a record low. Runoff above Sioux City, Iowa, in October was less than half of normal.

"Much of the basin remains dry and shows no signs of improving. October's runoff was the fourth lowest in 106 years of record keeping,' said Larry Cieslik, chief of the Missouri River Water Management Division in Omaha. "Reservoir storage fell below its pervious record low of 40.8 million acre feet (MAF), ending the month at 40 MAF," said Cieslik. The previous low was set in January 1991. The amount of water currently stored in the reservoirs is nearly 17 MAF below average.

Gavins Point Dam releases averaged 28,000 cfs in October, compared to an average of 36,900 cfs. They are currently set at 29,000 cfs and will vary as necessary to meet downstream targets for the remainder of the navigation season. As previously announced, the season will be shortened 6 days to make up for the additional water released last winter for downstream water intakes.

A six-day shortening would normally result in support for the commercial navigation season thru the following dates: Sioux City, IA � Nov. 16; Omaha, NE � Nov. 18; Nebraska City, NE � Nov. 19 Kansas City, MO � Nov 21; Mouth near St. Louis, MO � Nov.25

However, during drought conditions the flows subside downstream more quickly due to the lack of inflow from groundwater and tributaries. Therefore, releases from Gavins Point will not be reduced until Nov. 17 to ensure that navigation flows will be maintained through Nov. 25 at the mouth.

"Releases will be reduced 3,000 cfs a day beginning on Nov. 17, reaching the winter rate of 12,500 cfs around Nov. 22. Temporary increases could be necessary during severe cold weather to prevent excessively low stages caused by ice build-up," said Cieslik. Moderate temperatures could allow releases to be set lower than 12,500 cfs.

September's runoff totaled 548,000 acre feet. "Our runoff forecast above Sioux City for 2003 has been reduced to 17.5 million acre feet (MAF)," said Cieslik. Normal is 25.2 MAF.

Some flow support for the Missouri River is currently being provided from two reservoirs in Kansas. The target flow is 2,000 cfs, but will vary depending on tributary inflow. Most of the support provided to date has been a result of the evacuation of flood control storage at the Milford and Tuttle Creek reservoirs.

Lewis and Clark Lake is currently at elevation 1207.5 feet msl. It will be held near that elevation through the winter.

Fort Randall releases averaged 27,100 cfs in October. During the first part of November they will range from 27,000 to 29,000 cfs as needed to maintain Lewis and Clark Lake near its desired elevation. As the navigation season ends, they will be gradually reduced to 11,000 cfs. Lake Francis Case ended the month at 1345.3 feet msl. It will continue its annual drawdown, ending November near elevation 1338 feet msl.

Lake Oahe dropped nearly three feet during October, ending the month at elevation 1578.2 feet msl. The reservoir fell below its record low of 1580.7 feet msl on Oct. 2. the previous record was set in November 1989. It will end November near its current elevation, which will be 23 feet below normal. The reservoir is 7 feet lower than last year at this time.

Garrison releases averaged 10,800 cfs during October and increased from 10,000 cfs to 11,000 cfs in early November. They will be gradually increased this month for electricity generation, reaching 20,000 cfs in early December. Lake Sakakawea fell nearly one foot in October, ending the month at 1820.1 feet msl. It will drop one foot in November, ending the month 19 feet below normal. The lake is nearly 7 feet lower than last year at this time.

Fort Peck releases average 4,600 cfs in October and will be gradually increased, reaching 9,000 cfs in early December. The lake dropped less than one foot in October, ending the month at elevation 2209.3 feet mal. It will fall less than one foot in November, ending the month 25 feet below normal. Last year at this time it was 8 feet higher.

The six main stem powerplants generated 589 million kilowatt hours (kWh) of electricity in October, 67 percent of normal. the forecast for 2003 energy production is 7.6 billion kWh compared to a normal of 10 billion kWh.

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