Pacific Disaster Center Fostering Disaster Resilient Communities  

Reducing Flood Risk in Hawaii


Modeling Dam Failure Scenarios for the Hawaiian Islands

Property owners and communities can suffer severe losses when flooding occurs. Information resources that illuminate flood risks provide focus for mitigation and preparedness efforts that will help save lives and reduce economic impact. In early 2006, a series of record-breaking flood events inundated the Hawaiian Islands. The damage was compounded when the Ka Loko Dam failed on the island of Kauai, killing seven people and destroying several homes. With more than 100 dams in Hawaii, assessing potential flood risk is crucial to minimizing impacts from dam failure events.

Under contract with Hawaii’s Department of Land and Natural Resources (DLNR) Dam Safety Division, PDC modeled dam failure scenarios for all 135 dams registered in the state of Hawaii. Based on the output from these models, PDC created flood inundation maps that provided an overall view of water depth and flood travel time, an exposure assessment of community infrastructure, and an estimate of potential economic damage to private structures and businesses. The maps continue to provide a basis for assessing risk in Hawaii’s downstream areas, supporting emergency preparedness and evacuation planning throughout the state.

Homes in the Kilauea area of Kauai sit amidst the damage and muddy debris left by the collapse of the Ka Loko Dam in March 2006. (Image courtesy of Hawaii Department of Land and Natural Resources)