San Antonio River Authority logo

Digital Flood Insurance Rate Map


SARA Floodplain Viewer

Click image to access SARA Floodplain Viewer.

The SARA Floodplain Viewer engages users in an interactive map, displaying the Federal Emergency Management Agency’s (FEMA) National Flood Hazard Layer (NFHL) data. Together with its many Bexar Regional Watershed Management (BRWM) partners, the San Antonio River Authority collected the data used in the digital maps, providing basic information about the floodplains in Bexar, Wilson, Karnes and Goliad counties. To download FEMA Flood Data Sets, please visit https://msc.fema.gov/portal/advanceSearch


What is the “base flood?”

The base flood, or 100-year flood, is the flooding event that statistically has a 1-percent chance of occurring in any given year. Thus, the base flood can also be called the “1-percent annual chance flood.”

The SARA Floodplain Viewer outlines the 1-percent annual chance flood boundaries—indicating that those areas will be inundated by the flood event having a 1-percent chance of being equaled or exceeded in any given year.  The SARA Floodplain Viewer also shows moderate flood hazard areas, which are represented between the limits of the base flood (1 percent annual chance) and the 0.2 percent annual chance (or 500-year) flood.

By no coincidence, the Special Flood Hazard Area (SFHA)—as defined by FEMA—is the land area covered by the floodwaters of the base flood—that is the 1-percent annual chance flooding event.  This is important because the National Flood Insurance Program’s (NFIP) floodplain management regulations are enforceable in the SFHA, including the mandatory purchase of flood insurance.

FEMA encourages everyone to get flood insurance, even if you don’t live in a high-risk flood zone. While governments are doing all they can to alleviate the impact of floods, everyone should play a role in protecting themselves.

To learn more about flood insurance, click here to visit the FEMA National Flood Insurance Program site.

Map Modernization and Digital Flood Insurance Rate Maps

The SARA Floodplain Viewer, also known as a Digital Flood Insurance Rate Map (DFIRM), stemmed from FEMA’s Map Modernization Program, a multiyear Presidential initiative funded by Congress from 2003 to 2008. Map Modernization improved and updated the nation’s flood maps, providing 92 percent of the nation’s population with digitized maps.

In 2004, the SARA, and its BRWM partners undertook a comprehensive effort to update Bexar County’s floodplain maps as part of FEMA’s Map Modernization Program. In addition to converting the maps to a digital format, the BRWM updated flood studies and re-mapped many areas of the floodplain that were originally mapped in the 1970s.

FEMA approved the new Digital Flood Insurance Rate Maps (DFIRMs) for Bexar County in March 2010, and for Wilson, Karnes, and Goliad Counties in October 2010. Therefore, floodplain maps for your area might have changed based on more up-to-date flood studies.


410 starcrest flood pic

Frequently Asked Questions

Doesn't my homeowners insurance policy cover flooding?
If my home is flooded, won't federal disaster assistance pay for my damages?
Am I eligible for flood insurance?
I live in a low-risk flood zone. Do I really need flood insurance?
Why does my mortgage lender require me to buy flood insurance?
What if I want to purchase more insurance than the NFIP offers?
How do I find out what flood zone my home is in?
Here are links to web sites for some agencies and organizations related to Bexar Regional Watershed Management (BRWM):