US Army Corps of Engineers
Northwestern Division

News Releases

Missouri Basin flood response update – 10/11

Missouri River Water Management Division
Published Oct. 11, 2019
As of October 1, the projected runoff above Sioux City, Iowa is 61.0 million acre feet of water. The graph shows from January through September how much water has entered the Missouri River Mainstem system at each location including the reach above Fort Peck Dam, between Fort Peck and Garrison Dams, between Garrison and Oahe Dams, between Oahe and Fort Randall Dams (includes Big Bend Dam), between Fort Randall and Gavins Point Dams, and between Gavins Point Dam and Sioux City, Iowa (which is unregulated runoff primarily from the James, Vermillion and Big Sioux Rivers),

As of October 1, the projected runoff above Sioux City, Iowa is 61.0 million acre feet of water. The graph shows from January through September how much water has entered the Missouri River Mainstem system at each location including the reach above Fort Peck Dam, between Fort Peck and Garrison Dams, between Garrison and Oahe Dams, between Oahe and Fort Randall Dams (includes Big Bend Dam), between Fort Randall and Gavins Point Dams, and between Gavins Point Dam and Sioux City, Iowa (which is unregulated runoff primarily from the James, Vermillion and Big Sioux Rivers),

U.S. Army Corps of Engineers emergency and water management officials held a call Oct. 10 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.

There were 65 people on the call.

All of the information provided on these calls 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.

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.

“Since our last call on September 16, the basin has remained hydrologically active. We have had precipitation across the entire Missouri River basin, with significant rainfall occurring over eastern Montana, all of North Dakota, eastern South Dakota, and across Iowa and into northern Missouri. Some locations receiving [precipitation] in excess of 400% of normal for this time period. Many locations have received in excess of 6 inches of precipitation, a few pockets in excess of 10 inches,” said Low.

Low also discussed an early season snowpack over much of the upper basin in Montana, Wyoming, and the western parts of North and South Dakota. The estimates of the plains snow water equivalent vary from a trace to an inch. (Snow water equivalent is the amount of actual water contained in the snowpack. Depending on conditions, it is about 1 inch of water to 10-12 inches of snow. The snow water equivalent ratio can change dramatically depending upon temperatures, moisture in the air, wind, snowflake development, etc.)

Rivers and tributaries in flood stage include:

  • Minor flooding on the Missouri River in the Blair, Nebraska reach and minor to moderate flooding from Nebraska City, Nebraska to the mouth at St. Louis, Missouri (excluding the Kansas City, Missouri reach)
  • South Dakota: minor flooding along the James River and Big Sioux Rivers
  • Iowa: Minor flooding along the Big Sioux River
  • Kansas: minor flooding along the Big Blue River above Tuttle Creek Reservoir (backwater flooding)

Low discussed the ongoing winter storm in southeastern Montana, and North and South Dakota, noting significant impacts through Saturday with snow from the storm bringing the potential for as much as 3 inches of snow water equivalent.

According to the National Weather Service, the next seven days are expected to bring more moderate temperatures and melt the snow from this week’s storm increasing the potential for renewed flooding in the North Dakota portion of the James River, which will add to the ongoing flooding along James River in South Dakota.

Additionally, moderately heavy rain across the state of Missouri will likely cause minor flooding along many Missouri River tributaries through the weekend.

“The tributary contributions to the Missouri River will slow the current recession of the Missouri River below Kansas City,” said Low.

“Once we get past the winter storm on Saturday, the Missouri River basin is clear of precipitation for the remainder of the 7-day period. That is we’re clear Sunday through Wednesday. [October 13 – 16). Unfortunately, the long-range outlooks favor the odds of a wetter-than-normal condition for the Missouri River Basin, at least through January,” said Low.

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.

The first quantitative Spring River Flood Outlook, which is issued by the National Weather Service will be issued in early February 2020. Dates will be publicized as soon as they are available.

Upper Missouri River System (above Sioux City, Iowa)

John Remus, chief of the Missouri River Basin Water Management Division, reiterated the life and safety are the number one priority for operating the Missouri River Mainstem reservoir system and the flood control purpose has been driving operational decisions since March 2018.

“It is important to understand that floods can and will occur regardless of basin or system conditions, including ice-induced flooding during the winter freeze-in and spring-breakup periods, and flooding due to thunderstorms – particularly along the lower Missouri River which cannot be mitigated by the operation of the mainstem reservoirs,” said Remus.

“2019 continues to be a very wet year throughout the basin. This has led to excessive runoff into the reservoirs, and into the unregulated streams below the system. We will continue to evaluate the conditions on the ground and make adjustments as necessary,” he added.

Calendar Year Runoff (above Sioux City, Iowa)

Kevin Grode, the reservoir regulation team leader provided an update on runoff conditions for the 2019 calendar year, which is forecast to be 61 million acre feet (MAF), or nearly 2.5 times the average recorded runoff. This information is updated each month and posted here: https://go.usa.gov/xVtFq

“As of October 10, the observed upper basin runoff is 54.7 million acre feet. The 2019 runoff has already exceeded the 1997 total runoff volume of 49.0 million acre feet, which until this year was the second highest runoff in 121 years of record-keeping. If realized, the forecast of 61.0 million acre feet would equal the previous record runoff, which was established in 2011,” said Grode.

September runoff was much above average in all reaches.  In particular, continued heavy and widespread rains in South Dakota resulted in record September runoff in the lower mainstem reaches: Runoff from Gavins Point to Sioux City was more than 16 times the long-term average and more than twice the previous record. Gavins Point runoff was over 4 times average and almost twice the previous record. Fort Randall runoff was over 12 times average and set a new record, and Oahe runoff was over 4 times average.

The Oct. 1 runoff forecast projected above average runoff for the remaining three months of 2019. For October, the forecast that runoff would be 3 times the long-term average. This is largely in part to the tributaries continuing to flow much above average from the September rains along with the soil moisture conditions being extremely wet, which limits infiltration from any rain events. Through the first 10 days of October, the runoff has been 3 times average, as expected.

For November and December, the runoff forecast projects inflows to be about 2 times average.

Reservoir Storage and Regulation

Mike Swenson the power production team leader provided an update on the three-week forecast issued on Oct. 9. System storage is currently 63.2 MAF, down about 0.9 MAF since Sept. 30, with 7.1 MAF in flood control storage https://go.usa.gov/xVgWr.

The updated 3-week forecast shows Gavins Point releases will be held at 80,000 cubic feet per second (cfs) through October to manage reservoir levels and continue evacuating water from the reservoirs.

Fort Randall reservoir is at elevation 1355.8, down 3.1 feet since the end of September. Releases from Fort Randall are currently 74,500 cfs and are expected to average about 76,000 cfs by the end of October.

Oahe reservoir is at elevation 1614.2, down 0.7 feet since the end of September. The reservoir is 6.7 feet above the base of the annual flood control zone. Releases from Oahe are currently about 61,000 cfs and will increase to 62,000 cfs next week and are expected to remain near that rate through October.

Garrison reservoir is at elevation 1845.1, down 0.7 feet since the end of September. The reservoir is 7.6 feet above the base of the annual flood control zone. Releases are forecast to remain at 46,000 cfs through October.

Fort Peck reservoir is at elevation 2242.2, down 0.5 feet since the end of September. The reservoir is 8.2 feet above the base of the annual flood control zone. Releases from Fort Peck are expected to remain at 15,000 cfs through October.

“We will continue to monitor conditions in the basin and make any necessary release adjustments through the fall,” said Swenson.

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

Kansas River Basin Conditions:

Chris Purzer from the Kansas City District provided an update on the 18 District reservoirs on the Kansas, Osage, and Republican River basins with current reservoir conditions and water management decisions moving forward.

According to Purzer, the four reservoirs in the Lower Kansas River Basin are at 54% of their flood control storage occupied

  • Milford: 53% of flood control pool occupied, 19 feet above normal pool.
    • Releases are 1,000 cfs increasing to 2,000 cfs
  • Tuttle Creek: 59% of the flood control pool occupied, 44 feet above normal pool.
    • Releases are 6,000 cfs may increase to 10,000 cfs as conditions allow.
  • Perry: 49% of the flood control pool occupied, 17 feet above normal pool.
  • Clinton: 35% of the flood control pool occupied, 12 feet above normal pool.

On the Republican River, Harlan County has 25% of the flood control pool is occupied, 9 feet above normal pool.

Tuttle Creek and Milford have water accumulating in their phase II flood control storage and the Missouri River flow constraint at Waverly is 180,000 cfs. Projects with water stored in phase I storage zones have releases restricted to zero or low flow releases. These projects are Harlan County, Perry and Clinton.

“Without significant further rains, all phase II storage will be evacuated within 14 days. The release schedules from Tuttle Creek and Milford will be adjusted within this window to permit the follow-on release of phase I storage. There must be space in the Missouri River at Waverly below 140,000 cfs to allow phase I storage to be released. We anticipate flood storage in the Kansas River Basin reservoirs will be emptied by late December,” said Purzer.

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.

Kneuvean noted that the Kansas City District Emergency Operations Center remains activated at Level 2, Partial Activation.

“Missouri River levels are forecast to remain higher than normal as we move into the fall. We continue to monitor river conditions and remain prepared to fulfill requests for direct and technical assistance on an as needed basis,” said Kneuvean.

Levee rehabilitation

Requests for assistance to the Kansas City District remain at 106 requests for levee rehabilitation assistance. It expected these requests will result in approximately 67 levee rehab projects after bundling multiple requests for segmented levee systems. Project Information Reports submitted for approval by higher headquarters total 54, and of those reports, 50 have been approved and will now enter the engineering and design phase.

“Three of the approved projects have recently been advertised for construction and bids are due back by late October and early November. We anticipate the majority of levee rehabilitation projects to be advertised this winter with bids following 30 days from the date of advertisement,” said Kneuvean.

Levee Sponsor outreach meetings are being conducted, most recently in Napoleon, Missouri and in Holt County, Missouri.

“Both meetings were very well attended with more than 40 levee owners and operators at each,” said Kneuvean.

These meetings are intended to keep levee sponsors informed of the rehabilitation process and provide guidance on cost share options, real estate agreements, easements, and project cooperation agreements, all of which are required before construction can begin.

Final Levee Sponsor Outreach Meeting

  • Location: City Hall, Council Chambers
  • 405 Jefferson Street, Washington, Missouri

Big Tarkio Levee

“Construction on the emergency measure to close breaches on the Big Tarkio Levee in Holt County, Missouri has been stalled due to high water. Before construction was halted, work on the left descending bank was 90% complete while work on the right descending bank was 75% complete. Construction will begin on both banks once conditions allow for safe access to the worksite,” said Kneuvean.

Flooding has stalled Rock placement at the Mill Creek levee due to inaccessibility. A plan is in place to improve accessibility to the site by raising Highway 111, a contact modification is required as well as a permit from BNSF Railroad for haul trucks to use an existing temporary crossing near the worksite. Additional permits from the Missouri Department of Transportation are also being acquired to raise HWY 111.

“Please be river aware as higher than normal river levels will persist throughout the fall. Flood water can always pose a threat to life safety, please be safe and always pay attention to watches and warnings issues by the National Weather Service,” 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, the corps has completed 13 initial breach closures within the Omaha District’s area of operations. Ten of the breach closures are on the mainstem Missouri River and three are on the Platte River. On the left bank of the Missouri River, 26 breach closures remain,” said Krajewski.

Levee Status Updates

R616-613:

  • August 7 contract awarded
  • October 14 work completion for R616 expected
  • On schedule for remaining work R613
  • November 5 expected contract completion

L611-614

  • September 7 follow on contract awarded, 120-day performance period to place clay and repair levee damage north and south of Highway 34.
  • September 27 clay import and placement import began

L601

  • Emergency breach erosion control matting and riprap placement is substantially complete and the contractor will be demobilizing this week.

L575

  • L575 repairs are receiving additional berm width and riverside face protection. These efforts are necessary for the final repairs and will be capped with clay material that is currently being mined and stockpiled on site.

L594

  • September 16 contract awarded to close the breaches east and west of the BNSF railroad. A temporary plug was placed in the Waubonsie Creek to help aid the construction of the breach closures by stopping backwater effects from the Missouri River. This plug will be removed upon completion of the closures.

L550 A & B

  • Initial breach repairs are nearing completion and we are preparing to move forward with interim repairs.

Hamburg Ditch 6

  • Coordinating with City of Hamburg. Water is still on both sides of the existing levee, making construction nearly impossible. The city has asked not to change the current level of protection until after the spring. As such, construction will be postponed until after the spring runoff season.

Tributary Levee Projects

  • Pierce, Nebraska – project is complete
  • Scribner, Nebraska – contract awarded
  • Western Sarpy County, Nebraska – contract awarded
  • Broken Bow, Nebraska – contract awarded
  • Columbus, Nebraska – contract awarded
  • Ida Grove, Iowa – contract awarded
  • Cedar Creek Levee, Nebraska – contract awarded

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

“We continue to remain vigilant monitoring storms, runoff, and gage readings; and we can’t reiterate enough that life safety continues to be the primary focus of our efforts to repair the levee systems. We continue to work with federal, state, and local emergency management agencies to keep the public informed,” said Krajewski.


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

Release no. 19-065