Port Orchard Stormwater Infrastructure and Sea Level Rise Analysis

Sea level rise has the potential to damage stormwater systems through flooding and coastal erosion. Urban flooding can be exacerbated when stormwater systems are unable to drain and "backflow" because elevated sea level is pushing back against the stormwater. Herrera supported the City of Port Orchard in assessing potential vulnerabilities of the City’s marine shorelines and stormwater infrastructure with future higher water levels. We assessed multiple sea level rise scenarios and developed a set of maps indicating the risk of inundation and exacerbated flooding associated with different stormwater infrastructure. We also supported the city in updating its Shoreline Master Program, improving city code to reflect more recent FEMA flood insurance mapping, and communicating potential code changes to the City Council and residents.