Project Name: Willow Creek Missouri Valley, IA
Location: Missouri Valley, Iowa
Authority: Section 205 of the Flood Control Act of 1948, as amended
Sponsor: City of Missouri Valley
Current Phase: Feasibility

The ciy of Missouri Valley (non-Federal sponsor) is partnering with the U.S. Army Corps of Engineers (Omaha District) on a feasibility study to evaluate possible flood risk management solutions along Willow Creek and the Boyer River in Missouri Valley, Iowa. 

Missouri Valley, including large areas between Interstate 29 and the bluff line north of Highway 30, is subject to frequent flooding from Willow Creek and the Boyer River. Willow Creek, a tributary of the Boyer River, flows along the west side of Missouri Valley while the Boyer River flows along the east and south sides of the city.

Levees along these stretches are non-engineered spoil banks that have been evaluated by the USACE but not certified and only provide a 10-year level of flood risk management. In May 2007 during a high flow event, spoil bank levees along Willow Creek failed upstream of Missouri Valley and flooded homes and businesses contributing to an estimated $3 million in damages. During a September 2014 high flow event, a spoil bank levee along the Boyer River breached approximately two miles east of Missouri Valley near U.S. Highway 30. Roughly 70 people along a four-block stretch were forced to evacuate. 

The feasibility study is being conducted under Section 205 of the Flood Control Act of 1948 which allows the USACE to construct projects to reduce damages caused by flooding. During the feasibility phase, the USACE will ask the public for its input on the project and conduct a variety of detailed environmental, economic, and engineering analyses to develop possible solutions that are beneficial to the public, economically viable and environmentally acceptable.
 
Project Update:  The Omaha District and city of Missouri Valley team is working on the draft feasibility report.  The report is available for public review and comment from August 3rd, 2023 to September 4th, 2023. For more information, contact cenwo-planning@usace.army.mil. 

The draft feasibility report and appendices can be found here: Willow Creek, Missouri Valley, IA, Section 205 feasibility study, flood risk management: Draft integrated feasibility report and environmental assessment - Project Management Reports - USACE Digital Library (oclc.org)