KANSAS CITY, Mo. — The Kansas City District, U.S. Army Corps of Engineers was authorized a deviation from the operating manual for cumulative releases from reservoirs in the Kansas River Basin.
This decision was made in consultation with the Missouri River Basin Water Management through a thorough impacts analysis that addresses the downstream impacts of increased release targets and upstream impacts of not evacuating all the stored flood waters in the reservoir projects. Retaining flood storage in the Kansas River reservoirs into the next flood year presents unacceptable risk to downstream life and property for all stakeholders below the lower Kansas River reservoirs.
The 2019 flood resulted in flood control storage at the Kansas City District lakes and reservoirs being filled through the spring and summer months to alleviate downstream flooding on the Missouri River. Record setting rainfall hasn’t stopped, as many localities again set rainfall records in the month of August. Missouri River stages remain high, which leads to decreased releases from reservoirs along the Kansas River – most notably Milford, Tuttle Creek, Perry, and Clinton.
Currently, there is more than two million acre-feet of stored flood waters within the Kansas River Basin projects. To evacuate this storage prior to this winter’s freeze, the Kansas City District has received a deviation which allows it to increase the Phase 1 target on the Missouri River at Waverly from 90,000 cubic feet per second to 140,000 cfs. This is necessary, as a 90,000 cfs target is not expected to allow for releases from the lower 50 percent of flood control storage in the Kansas Basin until November or December. We estimate that the 140,000 cfs target at Waverly will facilitate emptying the stored flood waters over a three month period. Continued wet weather may prolong the drawdown.
Throughout the flood event, the Corps has shared vital information regarding the Missouri River system, and that all operations have impacts on one another. Exact dates and amounts of releases from the Kansas basin will depend on releases from Gavins Point, inflows to the Kansas River basin, and tributary inflows. Gavins Point releases are anticipated to remain at 70,000 cfs into October and remain above 60,000 cfs through November.
It’s important that the public remains vigilant, as higher river levels will persist. While the drawdown is occurring, it is anticipated the flow in the Kansas River, outside of local rain events, will remain between 20,000 cfs and 30,000 cfs. This is well below action stage along the Kansas River. 140,000 cfs at the Waverly gage on the Missouri river is approximately two foot above flood stage. Missouri River gages downstream of Waverly will be below flood stage at a flow of 140,000 cfs, but rainfall could result in them going over flood stage.