NOAA's Sea Level Rise Planning Tool
The National Oceanic and Atmospheric Administration (NOAA), in partnership with the Federal Emergency Management Agency (FEMA) and the U.S. Army Corps of Engineers, have developed a planning tool to help areas affected by Hurricane Sandy prepare for future sea level rise. The set of maps and the sea level rise calculator are intended to guide reconstruction planning for state and local officials, community planners, and infrastructure managers.
These maps provide best available elevation information for post-Sandy planning and rebuilding, as well as to support federal agency planning, as needed and applicable. These maps are not intended to support regulatory flood hazard zone designation, insurance ratings, or other legal or regulatory constraints. Rather, these maps and services support scenario planning that may help decision makers prepare for and adapt to uncertainties surrounding the future risks posed by sea level rise. They help make transparent the level of risk accepted under different scientific assumptions underlying the expected rate of sea level rise in the 21st century.
The maps outline future risks posed by extreme events, meaning the 1 percent annual chance of flooding as defined by FEMA's flood hazard data, combined with different scenarios of sea level rise by 2050 and 2100. They focus on potential flooding associated with sea level rise in New York and New Jersey, the areas hit hardest by the hurricane in October. The calculator complements the maps by providing site-specific details on projected flood elevations for five-year intervals from 2010 to 2100.
The maps combine FEMA flood hazard data with four scenarios of potential sea level rise from two peer-reviewed reports, including a NOAA-led interagency report on global sea level rise scenarios and a report by the New York City Panel on Climate Change. The four scenarios address different factors that could affect sea level rise, including ocean warming and the melting of mountain glaciers and ice sheets.
Information from the same two reports was used to update the corps' existing sea level change calculator, which also includes best available elevation data from FEMA. While the flood risk maps show the horizontal expansion of the existing floodplain over time, they do not predict future flood depths.