Greater Austin Floodplain Risk Zones and Hazard Data

Greater Austin flood risk data from the Digital Flood Insurance Rate Map (DFIRM) Database. It classifies areas by 1-percent, 0.2-percent, and 4-percent annual chance flood events, derived from Federal Emergency Management Agency studies and maps. The data is georeferenced using UTM projection for mapping at a 1:12,000 scale.

Use Cases

• Analyze spatial distribution of the 1-percent-annual-chance flood event zones for property risk assessment.
• Model flood hazard using the 0.2-percent-annual-chance flood event classification for extreme scenario planning.
• Compare areas of minimal flood risk against higher-risk zones for urban development planning.
• Integrate georeferenced UTM projection data with other GIS layers for comprehensive floodplain management.

Strengths

• Data is derived from authoritative Federal Emergency Management Agency (FEMA) Flood Insurance Studies and maps.
• Horizontal control specifications support mapping at a detailed scale of 1:12,000.
• Provides multiple flood risk classifications including 1-percent, 0.2-percent, and 4-percent annual chance events.

Limitations

• Specific data volume, row count, and column schema are unknown, limiting pre-analysis assessment.
• Relies on the accuracy of underlying FEMA studies, which may not reflect recent local changes in topography or drainage.

Provenance

Source

Federal Emergency Management Agency (FEMA) via the City of Austin.

Collection Method

Derived from Flood Insurance Studies (FISs), previously published Flood Insurance Rate Maps (FIRMs), and new mapping data.

Time Range

null

Freshness

Last updated March 2026.

Geography

Greater Austin area.