Press Releases

NYU Furman Center Launches FloodzoneData.us

May 25th 2017

Today, the NYU Furman Center announced the launch of FloodzoneData.us, an online data tool describing the people and housing located in the nation’s floodplains. The interactive map and data downloads make information available at the state, county, and Census tract levels. As sea levels rise and storms intensify due to climate change, FloodzoneData.us is a resource to help policymakers and communities plan for the effects of flooding.

The NYU Furman Center’s FloodzoneData.us combines housing and population data with FEMA maps of the 100-year floodplain (the term for areas with a one percent probability of flooding each year) and the 500-year floodplain (areas with a 0.2 percent probability of flooding each year).

“Severe climate events are becoming more common, and policymakers in areas across the country are grappling with how to address the risks to residents and communities from flooding,” said Jessica Yager, Executive Director of the NYU Furman Center. “Having access to data is crucial for effective disaster response and resilience planning. By providing detailed information about the population and housing stock in the floodplains, we hope this tool will help policymakers and communities plan for a more resilient future.”

According to a new analysis released in conjunction with FloodzoneData.us, Florida, Texas, and California have the largest numbers of housing units in the 100-year floodplain. In Florida, nearly two million occupied housing units are located in the 100-year floodplain; Texas has about 612,000 housing units and California has about 388,000 units in the 100-year floodplain.   

The NYU Furman Center also found that the majority of the housing units in the combined 100- and 500-year U.S. floodplains are single-family homes (64%) and are owner-occupied (62%).

The age of housing units in the U.S. floodplain, and thus how likely they are to be compliant with flood-resistant construction standards, varies widely; 22% of units in the 100-year floodplain were built before 1960 and therefore are less likely to be built to standards created with FEMA’s 1968 National Flood Insurance Program. Units built after 2000,  which are more likely to be compliant, account for the smallest share (19%) of housing in the 100-year floodplains.

A large share of all U.S. public housing units (9%) are located in the combined 100- and 500-year floodplains. In addition, 8% of all privately-owned subsidized rental housing units in the U.S. are located in the combined 100- and 500-year floodplains.

“The Kresge Foundation is pleased to support this effort to bring important data to the public, policymakers, and researchers about the people and housing at risk in our nation’s floodplains,” said Jalonne L. White-Newsome, senior program officer at The Kresge Foundation. “We hope this tool can be used to assist in both short-term and long-term planning to address the needs of communities living with the risk of flooding. This is a crucially important objective for a growing number of jurisdictions across the country, especially as climate change increases the frequency and intensity of severe weather events.”

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View the interactive map and downloadable data at FloodzoneData.us.

Read the data brief: Housing in the U.S. Floodplains

For more information, contact: Shannon Moriarty, sm4901@nyu.edu, w 212-998-6492, c 617-824-0069

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About the NYU Furman Center
The NYU Furman Center advances research and debate on housing, neighborhoods, and urban policy. Established in 1995, it is a joint center of the New York University School of Law and the Wagner Graduate School of Public Service. More information can be found at furmancenter.org and @FurmanCenterNYU.

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States with the Most Housing Units in the Floodplain*
*Estimates based on floodplain boundaries found in FEMA’s National Hazard Flood Layer, which does not include all areas with flood risk.

State with Largest Number of Occupied Housing Units in the 100-year Floodplain
Florida: 1,893,920
Texas: 611,937
California: 388,325
New York: 269,165
Louisiana: 247,341
Georgia: 231,038
New Jersey: 230,313
North Carolina: 225,079
Massachusetts: 181,393
Pennsylvania: 160,839

State with Largest Number of Occupied Housing Units in the Combined (100- and 500-year) Floodplain
Florida: 2,611,010
California: 1,964,142
Arizona: 1,774,600
Texas: 986,202
New York: 426,338
Louisiana: 337,611
New Jersey: 302,674
Georgia: 298,567
North Carolina: 281,882
Massachusetts: 253,606
               

Housing in the U.S. Floodplains

  • Most housing units in the nation’s floodplains are in single-family homes: 64% of units located in the combined 100- and 500-year floodplains are in single-family homes.
  • Most housing units in the nation’s floodplains are owner-occupied: 62% of units in the combined 100- and 500-year floodplains are owner-occupied.
  • The age of housing units in the floodplain, and thus how likely they are to be compliant with flood-specific construction standards, varies widely: 22% of units in the floodplain were built before 1960, before FEMA created the National Flood Insurance Program in 1968. Units built since YEAR account for the smallest share (19%) of housing in the floodplain.
  • Over 100,000 units of public housing—9% of the entire U.S. public housing stock—are located in the combined 100- and 500-year floodplains: 104,497 units of public housing units are located in the combined floodplains.
  • Over 300,000 units of privately-owned, subsidized rental units are located in the combined 100- and 500-year floodplains: 343,351 units (8%) of privately-owned subsidized rental housing are located in the combined floodplains.