Why did the study come about?

  • The Lower Missouri River sustained three devastating floods within 30 years: 1993, 2011 and 2019. The 2019 flood caused billions of dollars in damages to agriculture and infrastructure in communities in the states of Iowa, Nebraska, Kansas and Missouri. Repair costs to levee infrastructure damaged in 2019 in the lower river is approximately $1.2 billion. During the 2019 flood, the states of Missouri, Kansas, Iowa and Nebraska formed a four-state coalition to collectively address the repetitive flooding at a regional level. The goal was to develop actions in the aftermath of the 2019 flood to reduce system risk and recurring damages, improve system resiliency for the future and improve interagency collaboration.


What are the extents of the study?

  • The study extends 735 river miles of the Lower Missouri River from Sioux City, IA to the mouth in St. Louis, MO.


How was the study authorized?

  • Section 216 of the Water Resources Development Act (WRDA) 2020 authorized and expanded the initial feasibility study to a broader lower basin effort of a system evaluation over 735 Missouri River miles from Sioux City, Iowa, to the mouth near St. Louis, Missouri. In partnership with Missouri, Kansas, Iowa and Nebraska, the study will coordinate with state agencies, Tribes, stakeholders, levee districts, other agencies and the public to create a roadmap for a more resilient future for the Lower Missouri River, with a focus on flood risk management.


What are Spin-off Studies?

  • The Section 216 authority allows for site-specific feasibility studies (spin-off studies) in priority flood risk areas to begin the feasibility study phase prior to completion of the system plan. This concurrent effort allows for seamless progression into design for project areas with approved feasibility reports. Initial sites selected for further evaluation in a spin-off feasibility study include Holt County, Brunswick and Jefferson City in Missouri (links to individual study sites located below). These studies are more in-depth looks at these sites, and will formulate local, problem-specific solutions to address flood risks in these areas through the traditional USACE feasibility study process. More sites may be determined as the system plan progresses.


What will be the outcome of the Flood Risk and Resiliency Study?

  • The System Plan will offer solutions to improve flood risk for the Lower Missouri River at a scope and scale not done before. This is a once-in-a-generation opportunity to address repetitive flooding in predominately rural areas that have been negatively impacted by increased flooding over the past 30 years. The results of the study will produce a road map for the future to be utilized by local, state, and federal partners. The outcomes of the study will include system analysis providing construction recommendations for the initial spin-off studies, identify and recommend any additional spin-off feasibility studies and their locations, identify other projects to be implemented by other USACE programs and authorities (Silver Jackets, Continuing Authorities Program, etc), identify potential policy recommendations that would support the system, and outline potential actions that can be taken by local, state and other Federal stakeholders.


How do I provide input?

  • Comments can be sent to or via the comment box on the webpage or in the interactive map. There is also opportunities to submit comments and questions during public meetings and the quarterly webinars. All past and upcoming meetings and webinars are posted on our website.


When will the System Plan Study be complete?

  • The System Plan will be complete in March 2027.


How does the "Study" fit into the National Levee Safety Program being prepared by USACE and FEMA?

  • The study will provide updated overtopping frequencies for levee systems along the Missouri River. This is an important assessment for communities and stakeholders to know and manage for their risk living and working along the river. This information may be incorporated into the National Levee Database as the information is updated. As a federal partner, FEMA utilizes the NLD and other existing information on levee performance to inform their programs. For more information on FEMA assistance and programs, please contact FEMA.


Will the "Study" cause changes in the Floodway Boundary Lines for FEMA floodplain mapping?

  • USACE is using the study to formulate flood risk reduction alternatives. Updating base flood elevations (BFEs) or remapping floodways for FEMA is not part of this effort.  FEMA is using the updated flows from the USACE in a separate hydraulic modeling effort. FEMA intends to produce flood risk data for communities. USACE If you have additional questions about FEMA or the National Flood Insurance Program (NFIP), please contact FEMA.