The map below shows the currently mapped flood hazard zones in the vicinity of the Alamo Ranch area of far northwest San Antonio. The effective date for these maps is September 2010. There has been significant construction of homes, commercial buildings, and drainage infrastructure since that time.
The definition of the "100-year" flooding event that is the basis for the construction of the 1.0% Annual Chance Flood Hazard Zone is very likely to change based on increased frequency of major rainfall events in recent years. However, no information was found regarding plans for updates to these maps.
These maps and others for any area of interest around San Antonio are available via the interactive map viewer at the address below: