About 10% of land in Austin is in the floodplain, subject to the dangers of flash flooding. The Floodplain Office administers local and federal development rules, meant to limit damage and protect lives, and maintains floodplain maps and models.
Austin’s floodplains are the areas likely to flood when our creeks rise and flow over their banks. Every creek and lake has a floodplain, regardless of whether it is mapped or not.
The work we do ensures that Austin is compliant with FEMA rules, protects lives and properties, and allows Austin residents access to more affordable, federally-backed flood insurance.
Floodplains change over time due to development, capital improvement projects and other factors. We periodically restudy watersheds to keep pace with such changes. We are currently studying the Onion and Upper Brushy watersheds.