Hurricanes not only pack high winds, but can also cause torrential rains that lead to flash flooding and abnormally high waves and storm surge. Known as "The Triple Threat", each of these alone can pose a serious threat to life and property. Taken together they are capable of inflicting a large loss of life and widespread destruction.

In 1992, Hurricane Iniki's high waves and storm surge devastated the south shore of Kauai to elevations over 20 feet above sea level. As the hurricane nears the coastline, rapidly rising water levels from wind-driven waves and storm surge will inundate coastal areas, erode beaches, and pound and undermine waterfront structures and roadways.