Flood Risk Quiz

Flood Risk Mitigation

Flood Risk Mitigation

As a regional entity, the San Antonio River Authority, advocates a regional approach to flood control issues. Flooding knows no boundaries; what occurs upstream in Bexar County impacts communities downstream. The River Authority works with leaders in Bexar, Wilson, Karnes and Goliad counties to address flooding on a regional basis. The River Authority is developing hydrologic and hydraulic models to update flood plain maps throughout the Basin to improve flood warning systems, and to help identify and prioritize the most beneficial capital projects to address flooding issues.

To address flood risk, the River Authority performs flood risk studies by watershed and uses the results of those studies to:

  • Map flood risk and provide flood risk information to property owners and local governments.
  • Plan mitigation action through watershed master planning.


The River Authority also operates and maintains 41 flood retention dams throughout the river basin to reduce risk.

Cooperating Technical Partners (CTP)

The River Authority and the Federal Emergency Management Agency (FEMA) have developed a successful partnership towards the common goal of reducing flood risk. As a Cooperating Technical Partner (CTP), the River Authority works with local communities to implement FEMA programs and to incorporate local knowledge and data into flood hazard mapping and mitigation planning. The San Antonio River Authority has been a CTP with FEMA Region VI since 2003, during the “Map Modernization” program which converted paper Flood Insurance Rate Maps to Digital Flood Insurance Rate Maps. During the “Map Modernization” program the River Authority invested $14 million to comprehensively map over 1,700 stream miles in Bexar County using up-to-date topography, land use, impervious cover and rain fall data to update Bexar County’s decades old flood maps. Currently, the River Authority acts as a Letter of Map Revision (LOMR) Review Partner and manages Risk Mapping Assessment and Planning (Risk MAP) projects for the watersheds in the San Antonio River Basin. In 2018, the River Authority determined it was time to update the floodplain maps to capture new development and updated rainfall data into the flood insurance rate maps.