Preparations to reservoir system continue for 2020 runoff season

The U.S. Army Corps of Engineers continues to prepare the Missouri River Mainstem System for the 2020 runoff season.

Gavins Point releases were increased from 30,000 cubic feet per second to 35,000 cfs this week. Gavins Point Dam winter releases normally range between 12,000 and 17,000 cfs.

“All water from 2019 emptied from the System in late January. The higher-than-average winter releases from Gavins Point will allow us to maintain more flood storage for a longer period. This will provide flexibility to respond to runoff events downstream of Gavins Point while giving consideration to the ongoing levee rehabilitation construction efforts,” said John Remus, chief of the Corps’ Missouri River Basin Water Management Division.

“Conditions permitting, releases from all projects will likely remain high during the remainder of winter. We will continue to monitor the basin conditions and will remain aggressive in our releases to the extent it is practicable,” added Remus.

The 2019 calendar year runoff was 60.9 million acre-feet, the second highest runoff in 121 years of record-keeping (1898-2018), exceeded only by the 61.0 MAF of runoff observed in 2011. Based on current soil moisture conditions, current plains and mountain snowpack, and long-term temperature and precipitation outlooks, the 2020 calendar year runoff forecast is 36.3 MAF above Sioux City, Iowa, 141% of average. Average annual runoff is 25.8 MAF. Runoff forecasts will be updated monthly, and more often if warranted, throughout 2020.

As of Feb. 3, the total volume of water stored in the System is 56.3 MAF, occupying 0.2 MAF of the 16.3 MAF combined flood control storage zones.  System storage reached 56.0 MAF on Jan. 22, 0.1 MAF below the base of the combined flood control zone.

The potential for above normal runoff, coupled with above normal stages on many uncontrolled tributaries that join the Missouri River after the Gavins Point Dam, increases the potential for flooding, particularly south of Omaha. “I encourage all interested parties to monitor National Weather Service river forecasts, Missouri River Water Management reports and set up weather alerts for the most up-to-date weather and river information,” said Remus.

Navigation:

Current studies indicate that Missouri River navigation will be supported above full service levels for the first half of the 2020 season, which begins April 1 at  St. Louis, Missouri. The actual service level will be based on the total volume of water stored in the System on March 15, in accordance with the guidelines in the Master Manual. Flow support for the second half of the navigation season, as well as navigation season length, will be based on the actual July 1 System storage.

Ice Conditions:

River ice conditions below all System projects will be closely monitored throughout the winter season. The Corps will also continue to monitor basin and river conditions, including plains and mountain snow accumulation, and will adjust System regulation based on the most up-to-date information. The river ice report is available here: https://go.usa.gov/xpZZX.

Mountain Snowpack:

The mountain snowpack accumulation period is underway. Mountain snowpack is currently about average in both reaches; however, the mountain snowpack accumulation has approximately 2 months remaining. The mountain snowpack normally peaks near April 15. The mountain snowpack graphics can be viewed here: https://go.usa.gov/xE6wT.

Weekly updates on basin conditions, reservoir levels and other topics of interest can be viewed here: https://go.usa.gov/xE6wa.

Final 2019-2020 Annual Operating Plan Released

After reviewing comments received on the draft, the Missouri River Basin Water Management Division developed and released the Final Annual Operating Plan for the Missouri River Basin for 2019–2020. The plan is posted at: https://www.nwd.usace.army.mil/MRWM/Public-Meetings. /.

Monthly Water Management Conference Calls

Water management calls include an update from the National Weather Service’s Missouri Basin River Forecast Center, an update on the Missouri River mainstem reservoir system operations, and updates on the ongoing and planned flood recovery efforts in both the Omaha and Kansas City districts. The next call for 2020 will be held Thursday, Feb. 6 for Congressional delegations; Tribes; state, county and local government officials, levee and drainage districts; and the media. Calls will be recorded in their entirety and made available to the public on the Defense Video and Imagery Distribution System at www.dvidshub.net/unit/usace-nwd.

Reservoir Forecasts

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

• Gavins Point Dam
  • Average releases past month – 29,100 cfs
  • Current release rate – 35,000 cfs (as of Feb 4)
  • Forecast release rate – 35,000 cfs
  • End-of-January reservoir level – 1206.3 feet
  • Forecast end-of-February reservoir level – 1206.0 feet
  • Notes: Releases will remain at 35,000 cfs in February, basin conditions permitting.
     
• Fort Randall Dam
  • Average releases past month – 26,300 cfs
  • End-of-January reservoir level – 1344.1 feet (up 4.3 feet from December)
  • Forecast end-of-February reservoir level – 1344.9 feet
  • Notes: Releases will be adjusted as necessary to maintain the desired reservoir elevation at Gavins Point.
     
• Big Bend Dam
  • Average releases past month – 29,000 cfs
  • Forecast average release rate – 27,200 cfs
  • Forecast reservoir level – 1420.5 feet
     
• Oahe Dam
  • Average releases past month – 28,300 cfs
  • Forecast average release rate – 27,400 cfs
  • End-of-January reservoir level – 1607.2 feet (falling 0.7 foot during January)
  • Forecast end-of-February reservoir level – 1607.5 feet
     
• Garrison Dam
  • Average releases past month – 24,300 cfs
  • Current release rate – 24,500 cfs
  • Forecast average release rate – 24,500 cfs
  • End-of-January reservoir level – 1838.0 feet (falling 1.2 feet during January)
  • Forecast end-of-February reservoir level – 1837.6 feet
     
• Fort Peck Dam
  • Average releases past month – 12,800 cfs
  • Current release rate – 13,000 cfs
  • Forecast average release rate – 13,000 cfs
  • End-of-January reservoir level – 2235.3 feet (down 1.7 feet from December)
  • Forecast end-of-February reservoir level – 2234.2 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 928 million kWh of electricity in January. Typical energy generation for January is 711 million kWh. The power plants are projected to generate 11.4 billion kWh of electricity this year, compared to the long-term average of 9.4 billion kWh.

Web app:

The Missouri Basin Update Web App provides one-stop-shop access to regularly updated information from the official sources including the National Weather Service, US Army Corps of Engineers, US Geological Survey and others. Visit the page and save it to the home screen on your smartphone. http://go.usa.gov/xE6fC