More flooding is predicted in the Missouri River basin, officials from the National Weather Service and Army Corps of Engineers said Monday.
Areas to the north of Kansas City, including in eastern Montana, North Dakota, South Dakota and Nebraska, experienced 400 percent of the normal amount of precipitation in the first two weeks of September, according to Kevin Low from the NWS’s Missouri Basin River Forecast Center, and there is ongoing flooding in South Dakota, Iowa, Kansas and Missouri. River conditions were discussed during a conference call on Monday.
The Missouri River is in minor flood stage from Nebraska City, Nebraska, to St. Joseph, Missouri, and from Napoleon, Missouri, to Miami, Missouri. The Big Blue River is currently in flood stage above Tuttle Creek in Kansas.
While the Missouri River in the Kansas City area is not currently in flood stage, rain is forecast for Thursday through Sunday here. A NWS hydrology chart showed the Missouri River here may rise to action stage.
Floods will occur regardless of basin or system conditions, including ice-induced flooding during the winter-spring breakup periods, and flooding due to spring and summer thunderstorms, particularly along the lower Missouri River, which cannot be mitigated by operations of the mainstem reservoir system, according to John Remus, chief of the Missouri River Basin Water Management Division at the Corps of Engineers.
In response to the heavy rains and runoff to the north, the Corps of Engineers reduced water releases from Gavins Point Dam from 70,000 cubic feet per second to 60,000 cfs last weekend, he said. This reduction will continue no longer than three days, he said.
The reduction is an attempt to reduce the peak stage between Sioux City and Omaha and may prevent the flood from overtopping I-29 north of Omaha, he said.
Remus said the reservoir water releases then will increase gradually from 60,000 cfs to 80,000 cfs, and will be held at 80,000 cfs for several weeks. This could be well into October, he said.
Officials said Gavins Point releases will increase each day by 5,000 cfs starting Wednesday morning, reaching 80,000 cfs Saturday.
Remus said these increases were going to be necessary to evacuate the waters in the reservoirs. They need to evacuate more than half of the flood control storage in a little more than 11 weeks, he said.
Officials are trying to get the excess water out of the reservoirs by the first of December.
Any places that flooded previously in 2019 could be subject again to more flooding within the next week or so, according to officials.
While some levees that failed earlier this year have already been restored, others have not.
According to Kevin Grode, team leader for reservoir regulation in the Missouri River Water Management Division, the runoff forecast has increased from 54.6 million acre feet Sept. 1 to 58.8 million acre feet. It is more than two times average and just short of the record 61 million acre feet in 2011, he said.
Corps of Engineers officials from the Kansas City District said that they are reducing flows from Milford, Tuttle, Perry and Clinton reservoirs during the next few days. Future water releases will depend on the conditions of the Missouri River.
The Corps of Engineers has set a maximum of 140,000 cfs at the Missouri River at Waverly, Missouri, which is an increase from 90,000. The increase was necessary to empty stored flood waters at the reservoirs, according to officials. It will take 90 to 100 days to empty the flood waters, according to officials.
After a temporary reduction in water releases, the higher releases will resume, according to officials.
According to Mike Dulin, emergency manager for the Kansas City District, the Missouri River crest should reach Rulo, Nebraska, on Saturday or Sunday, Sept. 21 and 22, at a stage of around 22 feet.
While no levees are expected to overtop, previously overtopped levees could see some water move back into them, including Holt County, according to officials.
Buchanan County and Platte County, Missouri, also could see a rise in the Missouri River, officials said. They said they do not anticipate any major impacts.
Residents were asked to pay attention to flood watches and warnings this coming weekend.
According to a Corps of Engineers chart, the Wolcott levee, Section 1, a nonfederal levee in Kansas City, Kansas, overtopped and breached on March 23. The Wolcott levees, section 2 and 3, overtopped on March 23 but did not breach.
More detailed information about the river and reservoir conditions may be found at https://www.nwd.usace.army.mil/Media/News-Releases/Article/1961799/corps-hosts-call-to-update-stakeholders-on-reservoir-storage-plans/.