This layer displays the FEMA National Risk Index score, rating and national and state percentiles for each county and Census tract. These are measures of risks U.S. communities are exposed to for 18 natural hazards. Data was obtained from the FEMA National Risk Index (the March, 2023 version).
The Flood Hazard Zones are extracted from the National Flood Hazard Layer, which is a database that contains FEMA’s flood hazard map data. The database contains flood hazard information and supporting data used to develop the information. The primary flood hazard classification is indicated in the Flood Hazard Zones layer.
Flood zones are geographic areas that FEMA has defined according to varying levels of flood risk and type of flooding. For complete information about different flood zone designations, please visit the Definitions of FEMA Flood Zones web page.
Flood Hazard Zone Descriptions:
Floodway: The stream channel and that portion of the adjacent floodplain which must remain open to permit passage of the base flood.
1% Annual Chance Flood Zone: The 100-year or base floodplain.
0.2% Annual Chance Flood Zone: Area of moderate flood hazard, usually the area between the limits of the 100-year and 500-year floodplains, but also shallow flooding areas (< 1 foot) or flood zones for small drainage areas (< 1 square mile).
Area with Reduced Risk Due to Levee: Areas protected by levees from the 100-year flood.
1% Annual Chance Future Considerations: The 100-year floodplain based on anticipated future land-use conditions.
Area of Undetermined Hazard: Area of undetermined but possible flood hazard, typically occurring in counties with partial flood studies.
This information was acquired by state-level release May, 2024
This layer displays the FEMA National Risk Index score, rating and national and state percentiles for each county and Census tract. These are measures of risks U.S. communities are exposed to for 18 natural hazards. Data was obtained from the FEMA National Risk Index (the Nov. 2021 version).
This layer displays the total number of disaster declarations for 2012. Disaster events include severe weather events (likw tornadoes, hurricanes, and floods) as well as emergencies of man-made origin (like terrorist attacks or toxic spills). For more layers from this series, browse the Map Room data and navigate to Environment>Emergency Management.
Layer displays data from the FEMA National Shelter System database. The FEMA NSS database is synchronized every morning with the American Red Cross shelter database. Data about shelters in Illinois are unavailable.
This layer displays the total number of federal disaster and emergency declarations for flood events by county for through June, 2018. For this analysis, flood events include the following designated events: Mud/Landslide; Dam/Levee Break; and Flood.
For more layers from this series, browse the Map Room data and navigate to Environment>Emergency Management.
This layer displays the total number of federal disaster and emergency declarations by county for the year 2017. Disaster events include severe weather events (like tornadoes, hurricanes, and floods) as well as emergencies of man-made origin (like terrorist attacks or toxic spills). For more layers from this series, browse the Map Room data and navigate to Environment>Emergency Management.
The Flood Hazard Zones are extracted from the National Flood Hazard Layer, which is a database that contains FEMA’s flood hazard map data.
The Flood Hazard Zones are extracted from the National Flood Hazard Layer, which is a database that contains FEMA’s flood hazard map data. The database contains flood hazard information and supporting data used to develop the information. The primary flood hazard classification is indicated in the Flood Hazard Zones layer.
Flood zones are geographic areas that FEMA has defined according to varying levels of flood risk and type of flooding. For complete information about different flood zone designations, please visit the Definitions of FEMA Flood Zones web page.
Flood Hazard Zone Descriptions:
Floodway: The stream channel and that portion of the adjacent floodplain which must remain open to permit passage of the base flood.
1% Annual Chance Flood Zone: The 100-year or base floodplain.
0.2% Annual Chance Flood Zone: Area of moderate flood hazard, usually the area between the limits of the 100-year and 500-year floodplains, but also shallow flooding areas (< 1 foot) or flood zones for small drainage areas (< 1 square mile).
Area with Reduced Risk Due to Levee: Areas protected by levees from the 100-year flood.
1% Annual Chance Future Considerations: The 100-year floodplain based on anticipated future land-use conditions.
Area of Undetermined Hazard: Area of undetermined but possible flood hazard, typically occurring in counties with partial flood studies.
This information was acquired by state-level release February, 2020. Data release dates by state range from December 07, 2016 (Vermont) to February 12, 2020 (Utah).
The National Risk Index (NRI) is a dataset and an application that help identify communities most at-risk for natural hazards. The NRI leverages available source data for 18 natural hazards, social vulnerability, and community resilience to develop a baseline relative risk measurement for each United Statescounty and Census tract. The NRI is intended to help users better understand the natural hazard risk of their communities or assigned areas.