OMAHA, NE – Drought conditions continue across the upper Missouri River basin according to the U.S. Army Corps of Engineers. “With the exception of the Fort Peck to Garrison reach, runoff into the Missouri River mainstem reservoirs during July was below average due to the continuing drought conditions in the upper basin.” said Jody Farhat, chief of the Corps’ Missouri River Basin Water Management Division. “Runoff into Garrison was 124 percent of average, due to runoff from the remaining mountain snowmelt. July runoff ranged from 20 to 90 percent of average in the other reservoir reaches.” Runoff above Sioux City, Iowa for the month of July was 3.3 million acre feet (MAF), 101 percent of average. The 2017 runoff forecast for the Missouri River Basin above Sioux City, Iowa, is 27.9 MAF, 110 percent of average.

The total volume of water stored in the Mainstem Reservoir System is currently 61.4 MAF, occupying 5.3 MAF of the 16.3 MAF combined flood control storage zones. “System storage peaked on July 9 at 61.8 MAF and is gradually declining. The water currently stored in the annual flood control zone will be released during the remainder of the year to serve navigation, water supply and other downstream purposes and will be completely evacuated prior to the start of next year’s runoff season,” said Farhat.

As previously announced, the Corps will be providing flows to support full-service navigation as well as a full, eight-month navigation season. Full-service flow support is generally sufficient to provide a navigation channel that is 9 feet deep and 300 feet wide. “Gavins Point releases will be adjusted as necessary to meet full-service navigation targets in reaches with commercial navigation,” added Farhat. The September 1 system storage check will determine the winter releases from Gavins Point.

The Corps has announced that John Remus has been selected as the new chief of the Missouri River Basin Water Management Division. Mr. Remus currently serves as the chief of the Hydrologic Engineering Branch in the Corps’ Omaha District. Mr. Remus assumes the duties of the position in late August and replaces Ms. Farhat, who is retiring.
Weekly updates on basin conditions, reservoir levels and other topics of interest can be viewed here: http://www.nwd-mr.usace.army.mil/rcc/reports/pdfs/weeklyupdate.pdf.

The Corps will continue to monitor basin conditions and will adjust the regulation of the reservoir system based on the most up-to-date information.

Reservoir Forecasts

• Gavins Point Dam releases averaged 31,700 cfs during July. Releases were reduced from 33,000 cfs to 32,000 cfs on July 7, and then to 31,000 cfs on July 18. Releases are expected to remain near 31,000 cfs during August and will be adjusted as necessary based on downstream river conditions. The Gavins Point reservoir ended July at elevation 1206.3 feet and will remain near 1206.0 feet during August.
• Fort Randall Dam releases averaged 30,800 cfs in July. Releases will be adjusted as necessary to maintain the desired reservoir elevation at Gavins Point. The reservoir ended July at elevation 1356.0 feet and is expected to decline less than a foot in August.
• Big Bend Dam releases averaged 29,200 cfs in July. Releases are expected to average 29,700 cfs this month. The reservoir will remain near its normal elevation of 1420.0 feet during August.
• Oahe Dam releases averaged 33,200 cfs during July. Releases are expected to average 32,200 cfs in August. The reservoir ended July at elevation 1610.1 feet, declining 0.2 feet during the month. The reservoir level is expected to remain nearly steady during August.
• Garrison Dam releases were reduced from 34,500 cfs to 33,000 cfs in mid-July, averaging 33,500 cfs for the month. Releases are expected to remain near 33,000 cfs in August. Garrison reservoir ended July at elevation 1846.1 feet, declining 0.3 feet during the month. The reservoir level is expected to fall about 3 feet during August, ending the month near elevation 1843.2 feet.
• Fort Peck Dam releases averaged 9,900 cfs during July and are expected to average 10,000 cfs during August. The reservoir ended July at elevation 2239.0 feet, declining 1.2 feet during the month. The reservoir is expected to fall more than two feet during August ending the month near elevation 2236.8 feet.

The forecast reservoir releases and elevations discussed above are not definitive. Additional precipitation, lack of precipitation or other circumstances could cause adjustments to the reservoir release rates.

The six mainstem power plants generated 1,118 million kWh of electricity in July. Typical energy generation for July is 940 million kWh. The power plants are projected to generate 9.6 billion kWh of electricity this year, compared to the long-term average of 9.3 billion kWh.

To view the detailed three-week release forecast for the mainstem dams, go to http://www.nwd-mr.usace.army.mil/rcc/reports/twregfcast.pdf.

MISSOURI RIVER MAINSTEM RESERVOIR DATA

WATER RELEASES AND ENERGY GENERATION FOR JULY