The City of Sioux City has been awarded $865,000 from the Iowa Homeland Security and Emergency Management Levee Improvement Program to complete the Big Sioux River Levee Extension Project.

The Big Sioux River Levee Expansion Project is proposing to extend the Big Sioux River Left Bank levee system north along River Drive to replace the area identified for a temporary sandbag levee during high water events to reduce flood risk within the Riverside Area.

The Iowa Homeland Security and Emergency Management Levee Improvement Program provides financial assistance to local levee districts with at-risk levees to reduce the chances of a hazardous event occurring. Projects eligible for the funding must support the improvement, rehabilitation, maintenance or repair of a levee to support flood protection. Staff prepared a grant application in November 2024 to cover 50% of the estimated design and construction costs. The funding requires a 50% cost share by the City and property acquisition costs could not be covered under grant funding.

Since this project will alter a US Army Corps of Engineers federally authorized civil works project (i.e., the levee system) additional permitting will be required, including a Section 408 request. An Environmental Assessment for compliance with the National Environmental Policy Act (NEPA) will need to be completed in addition to geotechnical analysis, hydraulic analysis, topographic survey, and levee engineering. Upon completion of the project and a post-construction survey, FEMA Final Letter of Map Revision (LOMR) will need to be submitted.

The total project is estimated to cost over $2.65M and take 3 years to complete from commencement to final FEMA map revisions. Three homes along River Drive were purchased earlier this year and homeowners were relocated. The demolition of these homes is underway, and the engineering design process will begin in the next few months once the funding agreements are executed.