Floodplain Management

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.

Our office maintains floodplain maps and hydrologic and hydraulic models, administers floodplain regulations, provides information to help protect property impacted by floodplains and reviews applications to build or remodel in the floodplain.

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.

Floodplain Studies

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 re-studying 5 major watersheds, including:

These studies may reveal changes in the floodplains. FEMA has a formal process, including public hearings, for adopting any changes.

The City uses FEMA grants and drainage fees for the studies. They are done to identify and prioritize flood-related projects and provide better information to the public about flood risks.

In-Depth FEMA Documents Available for Download