Sea Level Rise Impact Assessment and Mitigation Alternatives Development for Balboa Island and Little Balboa Island, City of Newport Beach, California

The City of Newport Beach (City), a highly developed, densely populated coastal city in southern California is periodically subject to flooding from coincident high tides and waves. To prepare for sea level rise and potential flood damages, the City initiated a study to assess the potential flood impact to Balboa Island and Little Balboa Island. A recently developed 2D flood simulation model is utilized to investigate the effect of high tides occurring with increased sea levels. Additionally, a simple wave overtopping model is proposed to account for the effect of wind waves and ocean swells. The results of the flood model simulations were used to help the City to formulate flood inundation mitigation alternatives.