Greater Geelong Flood Extent Maps for Urban Planning

Flood extent polygons show areas designated as liable to flooding under Regulation 802 of the Building Regulations 2006. Data includes both high-quality floodmapping from detailed studies and lower-quality estimates from geological maps. The City of Greater Geelong created and maintains this dataset, last updated in April 2026.

Use Cases

• Identify properties within the 1% Annual Exceedance Probability flood polygon for regulatory compliance checks.
• Compare high-quality floodmapping features from the Barwon River study with estimated extents from Hovells Creek for accuracy assessment.
• Overlay flood extent polygons with land parcel data to calculate area and asset exposure for risk modeling.
• Use the geospatial polygons in a WMS service for interactive flood risk visualization in planning applications.

Strengths

• Data is explicitly linked to a specific legal regulation (Building Regulations 2006, Regulation 802).
• Provides multiple access formats including GEOJSON, SHP, and WMS for different technical workflows.
• Published under a permissive CC-BY-4.0 license for reuse and modification.

Limitations

• Data quality is explicitly noted as variable, ranging from high-quality flood studies to subjective estimates.
• No warranty is expressed or implied by the data provider, indicating potential positional or attribute errors.
• Specific row counts, file sizes, and temporal coverage of the source events are not provided.

Provenance

Source

City of Greater Geelong.

Collection Method

Combination of detailed flood studies (e.g., Barwon River) and subjective estimation from geological maps (e.g., Hovells Creek).

Time Range

Covers the largest recorded historical flood event and a design flood event (1% AEP). Specific years null.

Freshness

Last updated in April 2026, indicating active maintenance.

Geography

City of Greater Geelong, Victoria, Australia.