September precipitation was once again below average in the Missouri River Basin. September runoff in the Missouri River Basin above Sioux City, Iowa (upper Basin) was 0.8 million acre-feet, 67% of the long-term average. Soil conditions in the upper Basin continue to be very dry. According to the Drought Mitigation Center, approximately 88% of the Missouri River basin is currently experiencing some form of abnormally dry conditions or drought, which is a 6% increase from the end of August.

“Upper basin runoff was below average in September and is expected to stay low through the remainder of the calendar year. Lower basin runoff has been below average as well,” said John Remus, chief of the U.S. Army Corps of Engineers’ Missouri River Basin Water Management Division.  “Releases from Gavins Point Dam will continue to be set to maintain navigation support at an intermediate service level”, Remus added.  The navigation flow support season ends on Dec. 1 at the mouth of the Missouri River.

The 2021 calendar year runoff forecast for the upper Basin, updated on Oct. 1, is 14.8 MAF, 57% of average. Average annual runoff for the upper Basin is 25.8 MAF. If realized, this runoff amount would be the 10^th lowest runoff in 123 years of record-keeping.

Navigation

The July 1 System storage check indicated Gavins Point Dam releases will be set to provide flow support at an intermediate service level, 1,500 cubic feet per second less than full service flow support at all four target locations (Sioux City, Omaha, Nebraska City, and Kansas City). Full service flow support is designed to work in tandem with the Missouri River Bank Stabilization and Navigation Project to provide a 9-foot deep by 300-foot wide navigation channel from Sioux City, Iowa to the mouth of the river near St. Louis, Missouri. Gavins Point releases will be reduced to winter levels beginning around Nov. 22.

Winter Release Rate

The winter release rate is determined based on the Sept. 1 System storage. Per the Sept. 1 System storage, winter releases from Gavins Point Dam will be at least 12,000 cfs.

Draft Annual Operating Plan

In mid-September, the USACE posted the draft 2021-2022 Annual Operating Plan on its website at: https://www.nwd.usace.army.mil/MRWM/Public-Meetings/. The comment period on the draft AOP will close on Nov. 24. 

Fall Public Meetings

Fall public meetings will be held the week of Oct. 25-28. Specific dates, times and locations are listed below and can be found on the website at https://www.nwd.usace.army.mil/MRWM/Public-Meetings/.

The in-person meetings will adhere to the following COVID-19 meeting guidelines in accordance with the Department of Defense (but subject to change):

• Meeting attendance, including presenters cannot exceed 50.
• All attendees will be required to wear masks covering both the mouth and nose.

Do not attend if:

• You are experiencing symptoms of COVID-19 including fever or cough,
• You are awaiting the results of a COVID-19 test,
• You have received a positive COVID-19 test within the last 14 days, or
• You have been exposed to someone with COVID-19 within the last 14 days.

If you cannot attend, a meeting recording will be posted online at: https://www.nwd.usace.army.mil/MRWM/MRWM-News/
Questions may be submitted online at: https://www.nwd.usace.army.mil/MRWM/Questions/

Reservoir Forecasts:

• Gavins Point Dam
  • Average releases past month – 30,300 cfs
  • Current release rate – 32,000 cfs (as of October 1)
  • Forecast release rate – 32,500 cfs (month of October)
  • End-of-September reservoir level – 1207.2 feet
  • Forecast end-of-October reservoir level – 1207.5 feet
  • Notes: Releases will be adjusted as necessary to meet all downstream navigation targets.
     
• Fort Randall Dam
  • Average releases past month – 29,100 cfs
  • End-of-September reservoir level – 1352.9 feet
  • Forecast end-of-October reservoir level – 1344.6 feet
  • Notes: Releases will be adjusted as necessary to maintain the desired reservoir elevation at Gavins Point. The Fort Randall pool is normally drawn down to 1337.5 feet in the fall to provide space for winter hydropower generation at Oahe and Big Bend. The annual drawdown will continue in October and November.
     
• Big Bend Dam
  • Average releases past month – 25,100 cfs
  • Forecast average release rate – 20,600 cfs
  • Forecast reservoir level – 1421.0 feet
     
• Oahe Dam
  • Average releases past month – 24,900 cfs
  • Forecast average release rate – 21,100 cfs
  • End-of-September reservoir level – 1598.8 feet
  • Forecast end-of-October reservoir level – 1596.7 feet
     
• Garrison Dam
  • Average releases past month – 17,100 cfs
  • Current release rate – 13,500 cfs
  • Forecast average release rate – 13,500 cfs
  • End-of-September reservoir level – 1831.2 feet
  • Forecast end-of-October reservoir level – 1830.7 feet
     
• Fort Peck Dam
  • Average releases past month – 7,400 cfs
  • Current release rate – 5,000 cfs
  • Forecast average release rate – 5,000 cfs
  • End-of-September reservoir level – 2227.7 feet
  • Forecast end-of-October reservoir level – 2227.1 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.

Hydropower:

The six mainstem power plants generated 771 million kWh of electricity in September. Typical energy generation for September is 904 million kWh. The power plants are projected to generate 8.7 billion kWh of electricity this year, compared to the long-term average of 9.5 billion kWh.

To view the detailed three-week release forecast for the mainstem dams, go to http://go.usa.gov/xVgWr.