Flood Zones in Buchanan County, MO: Levee Risk

Buchanan County sits directly on the Missouri River, and its levee system was tested for real in March 2019, when the river broke a 1993 flood record that had stood for 26 years. A levee-protected designation on a flood map is not the same as flood-proof -- here's what actually happened, and what it means for evaluating a specific parcel.

This page covers what's specific to Buchanan County. For the general explanation, see the national guide.

March 2019: a modern record crest, and a levee system pushed to its limit

On March 22, 2019, the Missouri River reached a modern record crest of 32.11 feet at St. Joseph, surpassing the previous record of 32.07 feet set in July 1993 -- a record that had stood for 26 years. The rise was driven by a combination of upstream reservoir releases, snowmelt, and heavy rainfall across the Missouri and Mississippi River systems, prompting Missouri's governor to declare a state of emergency on March 21, 2019. Locally, the city and county issued a mandatory evacuation of areas behind the L-455 levee system on the Missouri side of the river and the R-471/460 levee on the Kansas side, displacing roughly 1,500 residents and 6,000 employees from businesses in the southern end of St. Joseph.

A river-crest forecast during the event indicated the levee could overtop, which is precisely why the evacuation was ordered rather than treated as precautionary -- county workers, local residents, and inmates worked to reinforce the levee with sandbagging as the crest approached. That's a materially different flood story than a levee simply existing on paper: this levee system was actively strained by a real, record-setting flood within the last decade, and the outcome (holding rather than failing) doesn't mean a future event of similar or greater magnitude will go the same way.

What levee protection does and doesn't mean for a parcel

A parcel located behind an accredited levee is often mapped by FEMA as outside the Special Flood Hazard Area for insurance purposes, but that designation depends on the levee continuing to meet FEMA's accreditation standards -- and, as March 2019 demonstrated, a levee that is technically holding can still come close enough to overtopping to require a full evacuation. Buchanan County's floodplain administrator (listed separately from the City of St. Joseph's own floodplain administrator) is the right first call for a levee-adjacent parcel: ask specifically whether the levee segment protecting that parcel is currently FEMA-accredited, what the current preliminary or effective FIRM shows for that specific location, and whether any levee-recertification or map-revision process is underway.

The city and county have been working through updated FEMA flood map products in the years following the 2019 flood, and preliminary map products for the area can be reviewed directly through FEMA's Map Service Center. Because levee recertification and FIRM updates are an ongoing, multi-year process rather than a one-time event, don't rely on an older flood-zone determination for a parcel near the Missouri River or behind either levee system -- pull the current preliminary and effective maps and confirm directly with the floodplain administrator before treating a parcel's flood-zone status as settled.

Flood Zones and Levee Risk in Buchanan County, Missouri

March 2019: a modern record crest, and a levee system pushed to its limit

What levee protection does and doesn't mean for a parcel

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