Dataset: Queensland Floodplain Assessment Overlay - Queensland Reconstruction Authority (QRA)



This data and its metadata statement were supplied to the Bioregional Assessment Programme by a third party and are presented here as originally supplied.

The Queensland Floodplain Assessment Overlay (QFAO) represents a floodplain area within drainage sub-basins in Queensland. It has been developed for use by local governments as a potential flood hazard area. It represents an estimate of areas potentially at threat of inundation by flooding. The data has been developed through a process of drainage sub-basin analysis utilising data sources including 10 metre contours, historical flood records, vegetation and soils mapping and satellite imagery. This data represents an initial assessment and will be subject to refinement by respective Local Government Authorities.

Dataset History

Lineage statement:

The Queensland Floodplain Assessment Overlay has been captured by analysis and visual interpretation of a combination of datasets (listed below in Sources).

Process step:

  1. Identify and overview sub-basin with satellite imagery backdrop.2. Overlay ordered drainage and floodplain data.3. Analyse drainage lines within the basin to determine the drainage lines that are relevant. At a minimum drainage lines with order 1 and 2 are excluded unless known events have occurred.4. Having determined the approximate extent in terms of drainage line hierarchy, overlay the 10m contours, gauging stations and flood lines of actual events from 2011.5. Determine the approximate flood elevation at locations within the drainage basin using gauging station data and actual events, together with visual interpretation of the imagery and other layers.6. Delineate the extent of the floodplain by visually interpolating between known locations using the satellite imagery and contours as the guide.Flood extent line revised over the town of Mareeba in the Barron River Basin sub area on 17-10-2013.


  1. 10m contours derived from 1 second SRTM (Shuttle Radar Topography), photogrammetry and LiDAR. In general, coverage of SRTM derived contours is west of the Great Dividing Range, Photogrammetrically derived contours coverage is over the Great Dividing Range and Cape York, LiDAR Contour coverage is the coastal fringe extending south of Cairns to the NSW border;2. Floodplain boundaries - derived by combination of Pre-clear Vegetation Mapping of Landzone 3 (Alluvium), Landzone 1 (Estuarine) and SALI Soil Flooding Limitation Mapping;3. Ordered Drainage (drainage lines);4. January 2011 Flood gauge readings and delineation of flooding events from aerial photography;5. 2009 SPOT satellite imagery;6. 2009 LandSAT satellite imagery.

Dataset Citation

Queensland Department of Natural Resources and Mines (2013) Queensland Floodplain Assessment Overlay - Queensland Reconstruction Authority (QRA). Bioregional Assessment Source Dataset. Viewed 06 May 2016,

General Information