Although the Alenaio Stream FCP has a history of being well maintained by the County of Hawaii, there are still residual risks that could lead to a breach or overtopping somewhere in the levee system. Past performance of the project during major flood events, such as the record-setting flood in November 2000, indicates that overtopping is likely to first occur over the channel walls upstream of the Kapiolani Street Bridge. “Floodwall B” has a history of localized erosion occurring at the base of the floodwall during large events that has since been repaired, but both floodwalls are still anticipated to perform as designed (to withstand the 1% annual chance exceedance event). In the event that one or more of the floodwalls experiences a breach failure, people and properties immediately adjacent to the floodwalls would be at the greatest risk. The initially high and fast-moving water at the breach location could be life threatening and cause significant property damage. As the water spreads into the leveed area, however, it would slow down rapidly and cause shallow flooding (typically less than 1 foot in height) to streets and low-lying areas as it flows toward the ocean. The State and County have extensively planned their response to a variety of emergencies, including a multi-layered system to alert residents and non-residents of their risk of imminent flooding. There is no site-specific emergency response plan, however, which would reduce the overall risk for this specific levee system. The leveed area includes the central business district for the community of Hilo and residential, commercial, and public structures. A flood would likely have social consequences to the Hilo community, negatively impact the regional economy, and may disrupt emergency response (fire/EMS) services located within the inundated area.