US Army Corps of Engineers
Northwestern Division

News Releases

Weekly Missouri Basin flood response update – 8/22

Northwestern Division
Published Aug. 22, 2019
Oahe Dam and Reservoir on the Missouri River are located near Pierre, South Dakota.

Oahe Dam and Reservoir on the Missouri River are located near Pierre, South Dakota. Lake Oahe has played a pivotal role during the 2018 runoff season allowing releases to be reduced from reservoirs downstream following heavy rain events and capturing flood waters from upstream mountain snowmelt and heavy rainfall in the Yellowstone River basin, which fell in May and June.

U.S. Army Corps of Engineers emergency and water management officials held a call August 22 to communicate to Midwest Congressional representatives, Tribal, state and local government officials (including levee sponsors and emergency managers) an update of current runoff conditions, system storage and a status of flooding response and recovery activities.

A recording of that call can be accessed here: https://www.dvidshub.net/audio/59513/missouri-river-basin-water-management-8-22.

It is also available via Podcast at: https://podcasts.apple.com/podcast/id508457675.

All of the information provided on this call is accessible through the Missouri Basin “Web App.” The information at the links in the web app is the most up-to-date information from the National Weather Service and the U.S. Army Corps of Engineers. https://go.usa.gov/xmtYU.

Northwestern Division Update

Tom Brady, with the Northwestern Division Readiness and Contingency Operations reported that the Omaha and Kansas City Districts have transitioned to recovery support along the Missouri River Basin and ongoing Phase 1 repairs, which include closing or repairing breaches where most critical infrastructure and population centers are at risk.

Teams continue to refine damage assessments to the 850 miles of impacted levees within the region, said Brady.

Phase 2 repairs are focused on full repairs. Of the 182 requests for rehabilitation assistance submitted to the Kansas City and Omaha Districts, 67 project information reports have been approved. These reports support requests for funding for subsequent engineering and design efforts for final repairs. Some of the construction projects for full repairs have already begun.

The entire levee rehabilitation effort for the Missouri River Basin has been estimated at $1 billion with additional expenses expected as requests for assistance and damage assessments continue.

National Weather Service

Kevin Low from the Missouri Basin River Forecast Center, National Weather Service, provided an update on river stages along the Missouri River and its tributaries.

Rivers and tributaries in flood stage include:

  • Minor flooding on the Missouri River from Nebraska City, Nebraska to  St. Joseph, Missouri and from Sibley, Missouri to Hermann, Missouri (excluding Jefferson City, Missouri)
  • South Dakota: James River, Big Sioux River
  • Kansas: Big Blue River above Tuttle Creek Reservoir (backwater flooding)
  • Missouri: Little Osage River, Osage River

Low said over the next seven days, wet weather will continue with rainfall from one half to up to 1 inch falling in eastern Montana through Friday morning. Scattered thunderstorms over southern Missouri with generally less than a half inch of rain predicted.

“Friday and into the weekend, scattered thunderstorm activity is possible over much of the basin with the heaviest activity in North Dakota, South Dakota, Nebraska and Iowa with amounts up to an inch and a half of rainfall,” said Low.

A front will set up over the southeastern portion of the Missouri Basin early next week which will bring more organized widespread rainfall. Heaviest amounts are likely in Missouri, eastern Kansas, and southern Iowa with rainfall averages could exceed 5 inches from Monday through Wednesday.

The National Weather Service provides official river stage and weather forecasts.  Its website -- www.weather.gov/mbrfc -- provides river observations and forecasts; weather observations and forecasts, and additional information including the spring flood outlook under items of seasonal interest. The Corps’ Missouri River Water Management Division shares all release forecasts with the National Weather Service for incorporation into their forecast products.

Upper Missouri River System (above Sioux City, Iowa)

The Missouri River Water Management Division provided an update on the three-week forecast issued on August 21. System storage is currently 66.6 million acre feet (MAF). https://go.usa.gov/xVgWr

Mike Swenson, from the Missouri River Water Management Division noted that system storage had declined by about 0.6 MAF in the past week with 10.5 MAF currently stored in the system’s flood control zones.

Releases from Gavins Point Dam will remain at 70,000 cubic feet per second into September to continue evacuating flood water.

Fort Randall reservoir is at elevation 1361.8 feet, which is down 0.6 feet since last week. The reservoir is more than 6 feet above its normal summer operating level. Releases are 68,000 cfs and will remain near that rate over the next week.

Oahe reservoir is at 1616.4 down 0.3 feet in the last week. The reservoir is 8.9 feet above the base of the annual flood control zone. Releases from Oahe are currently about 57,000 cfs and expected to remain near that rate through mid-September.

Maintenance at Oahe

Swenson noted that starting Monday, August 26, a maintenance project at Oahe will start on one of the hydropower units.

“Although total releases from Oahe will remain the same, releases will exceed the capacity of the available hydropower units, and supplemental releases will need to be made using the outlet tunnels. Outlet tunnel releases will begin Monday morning,” said Swenson.

Garrison reservoir is at 1849.4 feet down 0.9 feet in the last week and is no longer storing water in the exclusive flood control zone. Garrison Releases are expected to remain at 46,000 cfs into September.

Fort Peck reservoir is at 2244.8 feet down 0.5 feet in the last week. The reservoir is 10.8 feet above the base of the annual flood control zone. Releases are expected to remain at 15,000 cfs into September.

Lower Missouri River Basin (Kansas and Osage River Reservoirs)

Chris Purzer, from the water management division in the Kansas City District provided an update on the status of the reservoirs on the Kansas River and the Osage River. This information is available on their website at: https://go.usa.gov/xmhrd

On average, the four reservoirs in the Lower Kansas River Basin have 50% of their flood control storage occupied with Perry slightly elevated at 60% following recent rains, Clinton at 46% and Milford and Tuttle Creek at 51% of their flood storage pools occupied.

Perry is releasing 5,000 cfs and Clinton is releasing 1,500 cfs as they are remaining Phase II flood control storage.

Milford Dam is releasing 4,000 cfs and forecast to maintain this rate through the weekend. Tuttle Creek Dam is releasing 12,000 cfs, and may begin to reduce releases on Saturday to match inflows.

“We anticipate maintaining this operation in the short term as we determine a long term approach to emptying the approximately 2 million acre-feet stored in these four reservoirs [in the Kansas River basin],” said Purzer.

Conditions on the Osage River Basin are improving with 16% of their combined flood control storage occupied. Releases from Truman dam are 30,000 cfs and are scheduled to stay at this rate for the next two weeks.

Kansas City District Emergency Response

Jud Kneuvean, chief of emergency management from the Kansas City District provided an update on the status of flood response efforts and levee conditions. They keep this information updated on their website at: https://go.usa.gov/xmtYD.

To date, the Kansas City District levee rehab team has received a total 106 requests for levee rehabilitation assistance, 21 have been approved to enter the engineering and design phase.

“Construction on the emergency measure to close the breaches at the Big Tarkio River is in full swing,” said Kneuvean.

The contractor is working to close both banks of the Big Tarkio simultaneously. Efforts at Mill Creek have been stalled due to inaccessibility issues related to flooding.

“We are currently working solutions to improve our accessibility to the site,” he added.

Again, the purpose is to close breaches on both the Mill Creek Levee and the Big Tarkio Levee to prevent water flowing unabated across the flood plain. The work will also help Mill Creek and the Big Tarkio River to re-establish their pre-flood flow patterns by re-establishing the stream banks.

“Recent rainfall has again proved to be challenging in areas with damaged levee systems. Slight increases in river stages can result in additional flooding of areas that were first inundated in March. Please continue to pay attention to watches and warnings issued by the National Weather Service as conditions on the river can change quickly should heavy rainfall return to our region,” said Kneuvean.

Omaha District Emergency Response

Matt Krajewski, chief of the Readiness Branch for the Omaha District provided an update on the status of post flood levee inspections and rehabilitation. To date, 12 initial breach closures are complete within the Omaha District’s area of operations, with 39 remaining.

This week, the Omaha District advertised six tributary levee repair projects in Columbus, Scribner, Broken Bow Cedar Creek, and Western Sarpy County in Nebraska, and in Ida Grove, Iowa.

“Solicitations were sent to the 27 contractors on the pre-qualified sources list. Pre-bid site visits will be held beginning August 26th with the bids due on the first project by September 3rd,” said Krajewski. 

The initial breach closure for Levee L611-614 near Council Bluffs is about 95% complete with anticipated contract completion around some time tomorrow.

For Levee 601 near Bartlett, Iowa, sand berm construction is complete and the design height level of protection is in place. Remaining work includes replacing rip rap, erosion control matting, and deconstructing the Waubonsie haul road.

For Levee L-575 near Hamburg, Iowa, the District is working with project sponsors on finalizing cooperation agreements and Rights of Way so construction can commence on those repairs.

For Levee L550 between Watson and Rock Port, Missouri, the District anticipates the north breach be closed August 26. Work will then move to the south breach where the contractor has built a temporary haul road and has been stockpiling material.

For the Hamburg Ditch 6 levee, the District is working on engineering and design documents for rehabilitation back to its authorized level of protection.

“Engineering and design is currently ongoing on several other levees on the Missouri River and tributaries.  As these designs are completed, we will continue to move forward with contract awards and construction,” said Krajewski.

Omaha District levee status information is updated on their website at: https://go.usa.gov/xmtYB.


Contact
Eileen Williamson
402-996-3802
eileen.l.williamson@usace.army.mil

Release no. 19-057