Corp June Water Management Release

OMAHA – Storage in the Missouri River main stem reservoirs continues to increase, now only 1.5 million acre feet (MAF) less than average for this time of the year.

A pulse of water was put into the river from Gavins Point Dam on May 19 and 20 to benefit the endangered pallid sturgeon. Flows during the pulse remained well within the channel and no damage was reported along the 810 miles of the river from the dam to the Mississippi River.

“The runoff from melting snow and ice in the mountains put 1.6 MAF of water into the reservoirs in May,” said Jody Farhat, Chief of the Water Management office here. “The levels of the big reservoirs of Oahe, Garrison and Fort Peck have risen 10 feet, 7 feet and 5.5 feet respectively in the last two months,” she added.

The current forecast for runoff is 31.1 MAF, 125 percent of average. If the forecast verifies, the level of Oahe will peak near 1614 feet and Garrison near 1838 feet this summer. Fort Peck is forecast to peak near 2222 feet by the end of the year. Storage in the system of reservoirs ended the month at 54.8 MAF and is forecast to peak at 56.5 MAF in June. The last time it was at this level was in 2000.

Forecasts show that the commercial navigation season will most likely not be shortened this year. The final decision on season length and flow support for the second half of the navigation season will be made following the storage check on July 1.

Gavins Point releases averaged 18,600 cubic feet per second (cfs) in May. The average is 28,400 cfs. Releases will average 25,000 cfs in June.

Fort Randall releases averaged 16,400 cfs in May. They will be adjusted this month as necessary to maintain Gavins Point reservoir near its desired elevation. Fort Randall reservoir fell 2.5 feet during May. It will end June at elevation 1355.2 feet.

Big Bend reservoir will remain in its normal range of 1420 to 1421 feet. Releases will be adjusted to meet hydropower needs.

Oahe reservoir climbed just over a foot in May, ending at elevation 1613.6 feet msl. Releases averaged 13,000 cfs during the month and will average 20,400 cfs in June to provide downstream flow support. The reservoir will remain essentially level, ending the month near elevation 1613.6 feet msl, about 9.4 feet above its normal elevation. The reservoir is currently 6 feet into the flood pool and is 28.9 feet higher than it was last year at this time.

Garrison reservoir rose 3 feet in May, ending at elevation 1833 feet. Releases averaged 13,300 cfs during the month, compared to the long-term average of 21,000 cfs. The reservoir is expected to climb slightly more 4 feet in June, ending at 1837.2 feet, 0.9 feet below normal. It is currently 22.8 feet higher than last year at this time.

Fort Peck reservoir rose 3.5 feet in May, ending at elevation 2217.7 feet msl. Releases averaged 5,900 cfs, compared to the long-term average of 9,100 cfs. The reservoir will climb 2.6 feet in June, ending at elevation 2220.3 feet, 12.3 feet below normal. It is currently 17.4 feet higher than last year at this time.

The six main stem power plants generated 500 million kilowatt hours (kWh) of electricity in May, only 63 percent of normal because of lower pool levels and reduced releases from the dams. Total energy production for 2009 is forecast to total 7 billion kWh, compared to the average of 10 billion kWh.