A risk assessment was performed on the Big Five levee system in 2017, which identified underseepage as the primary risk driver for the levee. While some water seeping through and under the levee is normal in this region, seepage in many locations of the Big Five levee system has been severe enough to move soil particles from beneath the levee and deposit the material on the landside in the form of sand boils, which weaken the levee. Seepage has progressively gotten worse over time under lower flood loadings leading to increased concern for future levee performance. The levee districts have employed extensive flood fighting efforts in recent floods to prevent levee failure. Original features designed to control underseepage are old and no longer effective and in some cases were never installed due to local property disputes. The extent of any damage sustained within the levee system’s soil due to sand boils and seepage from previous floods is unknown. Underseepage becomes more severe during long duration flood events on the Mississippi River, as long-term pressure is placed on the levee embankment. Long duration flood events are typical on the Mississippi River. Though rare, there is a chance that Mississippi River flooding could overtop the levee. A flood of this magnitude is estimated to have less than a 1% chance of occurring in any given year. However, there is a greater chance that underseepage or other levee vulnerabilities could cause failure during a lower-level flood. These concerns are somewhat offset by the fact that a breach prior to overtopping would be slow to progress due to well compacted embankment soils that are resistant to erosion. This would likely allow ample time for residents to evacuate before a complete levee failure. In the event of an overtopping event, significant warning time would exist due to slow rising floods on the Mississippi River, which would allow for evacuation. Levee overtopping or failure would impact the local communities, cause economic hardship for the region, and result in loss of life if the population is not evacuated. The population nearly doubles during the nighttime, from approximately 970 to 1,700, as residents return home. A levee failure at night would therefore have greater consequences than one during the day, making the need for effective emergency warning system and evacuation notification procedures critical.