Waves breaking over railing overlooking the ocean on a stormy day
  1. Learn More
  2. Determining Risk
  3. Expected Annual Loss
  4. Coastal Flooding

Coastal Flooding

Coastal Flooding is when water inundates or covers normally dry coastal land as a result of high or rising tides or storm surges.

In the National Risk Index, a Coastal Flooding Risk Index score and rating represent a community's relative risk for Coastal Flooding when compared to the rest of the United States. A Coastal Flooding Expected Annual Loss score and rating represent a community's relative level of expected building and population loss each year due to Coastal Flooding when compared to the rest of the United States.

A map of the United States colored by Coastal Flooding Risk Index ratings. Coastal Flooding risk is possible all along the East and West Coast, and the Gulf of Mexico. It is most prevalent along the East Coast, the Gulf of Mexico, and the Pacific Northwest. For full results, see the National Risk Index Map webpage.

Coastal Flooding Exposure

A Coastal Flooding exposure value represents a community's building value (in dollars) and population (in both people and population equivalence) exposed to Coastal Flooding.

Coastal Flooding Annualized Frequency

A Coastal Flooding annualized frequency value represents the modeled frequency of Coastal Flooding hazard occurrences (events) per year.

Coastal Flooding Historic Loss Ratio

A Coastal Flooding historic loss ratio is the representative percentage of the exposed consequence type value (building or population) expected to be lost due to a Coastal Flooding hazard occurrence.

Coastal Flooding Processing Methodology

For comprehensive details about the Coastal Flooding processing methodology, see the National Risk Index Technical Documentation.

Related