Coastal Storm Surge Scenarios for Water Utilities

The Coastal Storm Surge Scenarios for Water Utilities, created by the U.S. Environmental Protection Agency (EPA), provides a visual representation using a map interface of hurricane strike frequency and worst-case coastal storm surge inundation scenarios (Storm surge inundation refers to the abnormal rise of water generated by a storm, over and above the predicted astronomical tides). This map aims to illuminate historical trends in coastal storm surges and flooding, in order to aid decision-makers tasked with improving coastal resiliency and emergency preparedness. This map is a part of the EPA’s broader Climate Ready Water Utilities initiative, a collection of resources designed to help water sector utilities adapt to climate change.

The content of this interactive map is derived from:

  • National Hurricane Center’s hurricane strike dataset, which is comprised of direct and indirect strikes from the different hurricane categories occurring between 1900-2009.
  • Federal Emergency Management Agency’s 100-year and 500-year flood plains, which focus on riverine and coastal flooding
  • National Oceanic and Atmospheric Administration’s Sea, Lake, and Overland Surge from Hurricanes (SLOSH) model, which focus on storm surge inundation

The map allows users to overlay data layers, such as:

  • SLOSH models for category 1-5 hurricanes
  • Hurricane return period, which are the frequence in which a certain intensity hurricane can be expected.
  • 500 year floodplain
  • 100 year floodplain

The Map includes tools to calculate distances and areas of any section on the map, and provides an extensive basemap gallery. The map also provides details on how the SLOSH model is derived, and the key differences between the assumptions and methods used to calculate the FEMA floodplain and SLOSH model. At any point in using the tool, users are able to share and print the current extent of the map they have created.


Publication Date: December 2011

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Resource Types:

  • Mapping tool


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