January 2005 Newport Harbor Flood

Flooding hazards projected by CoSMoS versus ground-truthed flooding extents from the January 2005 extreme tide event in Newport Harbor, CA. The tendency for CoSMoS version 1.0 to over-predict the level of flooding in protected embayments has been addressed through model enhancements in CoSMoS version 2.0.

January 2005 Newport Harbor Flood: An extreme high-tide event (king tide) coupled with an atmospheric low-pressure system caused significant flooding in Newport Beach on January 10, 2005. Newport Beach officials were deployed to manage the flood, and city personnel documented the flooded areas on Balboa Peninsula and Balboa Island with digital photographs. These data were interpreted and the flood extent was manually delineated using ArcGIS (Gallien and others, 2012). This represents the only known event and location where coastal flooding has been quantitatively determined along the entire U.S. west coast.

CoSMoS was run for this scenario and flood-hazard projections were compared with ground-truthed flood extents produced from city photos (see Newport Harbor figure) for model validation and to support local flood-prediction improvements.