Tools and Technologies

Digital Flood Insurance Rate Maps/Map Modernization

The Bexar County Digital Flood Insurance Rate Map (DFIRM) study, part of the national Federal Emergency Management Agency (FEMA) Map Modernization Program, is the most complete update to Bexar County’s flood risk maps since their creation in the late 1970s.

The DFIRM process used modern technology and up-to-date topography, land use, impervious cover and rain fall data to map flood risk. This $14 million project, started in 2004, mapped over 1,700 stream miles in Bexar County.

The San Antonio River Authority (SARA) managed the project; FEMA, Bexar County, the City of San Antonio, the City of Alamo Heights, the City of Windcrest and the City of Live Oak are funding partners in the project.

FEMA approved the maps on March 29, 2010, which marked beginning of a six-month local adoption period. The maps must be approved by all local governments within this six-month adoption period to ensure that the county and all cities remain in the National Flood Insurance Program (NFIP).

The new DFIRMs will be effective September 29, 2010. They can be seen here.

This map shows the streams and rivers that will be modeled and re-mapped in Bexar County. The effort includes more than 1,100 stream miles.

Click on the image above to view a larger version.