Flood studies and open data

Flood studies provide Brisbane City Council with technical data for managing all sources of flood risk from river, creek, storm tide and overland flow.

Council is committed to ensuring we have the latest flood modelling data to help manage flood risk in Brisbane.

Following the January 2011 floods, and in response to the Queensland Floods Commission of Inquiry and Council's January  2011 Flood Action Plan , Council is committed to undertake and maintain up-to-date flood studies for Brisbane catchments including working with the Queensland Government on Brisbane River flood studies. 

A flood study is a technical investigation of flood behaviour for a particular catchment, river or creek. The aims of a flood study are to define existing flood behaviour, including: 

• depths
• extents
• velocities.

Flood studies help inform practices such as building, land use planning, community awareness and disaster management, with the aim of minimising risk and protecting people, property and infrastructure. 

A flood study typically involves estimating catchment hydrology and hydraulics, commonly using computer-based flood modelling. This estimation utilises many types of digital information including ground level survey, bridge/culvert data, land use data, historic flood records, historic rainfall records and statistical analysis.  

Flood modelling is used to estimate: 

• the inundation extents of the areas that may be flooded
• the peak depths of flood waters
• the hazard related to the depth of water or how quickly the water flows (velocity).

Flood modelling is an important process to understand the full flood risk for an area, rather than relying only on historical events (which may not be applicable in current day). 

A flood study will usually produce several maps for each flood scenario and may show:

• flood extent (how far the water spreads)
• an indication of flood depth (how deep the water is across the flooded area)
• an indication of flood velocity (how fast and in which direction the water is travelling) 
• flood hazard (low, medium, high and extreme areas of hazard based on factors including velocity of the water and whether this poses a threat).

The flood extent, depth, velocity and hazard maps provide a good visual basis for understanding the potential flooding that may affect your property. These outputs form the underlying information presented in the Flood Awareness Map and FloodWise Property Reports. 

These studies are progressively being implemented into Council's FloodWise Property Reports, the Flood Overlay map in  Brisbane City Plan 2014  and the Flood Awareness Map. 

Hard copies of the flood studies are available for viewing in the  Brisbane Square Library . They can also be downloaded from the  Brisbane open data website.  

Flood studies are undertaken using the best available data and technology. Council conducts flood studies according to Queensland Government and Australian guidelines and policy, including: 

•  Australian Rainfall & Runoff Guidelines 
•  Queensland Urban Drainage Manual 
•  Queensland Government State Planning Policy 
•  Australian Disaster Resilience Handbooks 
•  Queensland Reconstruction Authority Guidelines. 

Following the completion of Council flood studies or acceptance of third-party studies (i.e. Queensland Government), updates to Council's flood information products are scheduled to be completed annually prior to the summer storm season.  

Flood Information Online may be updated out of schedule, if required, to reflect significant changes to source data.  

Council will  post updates online  advising when changes have been implemented. In cases of significant updates, Council may write to individual property owners. 

Through the  Brisbane Open Data  website, Council has released more than 1000 datasets that are re-usable, accessible and shareable. These datasets are available in a variety of formats and cover a wide range of topics including public transport, planning, environment, infrastructure and spatial data. A dedicated spatial data website allows for easy navigation and access to Council’s spatial data sets such as stormwater infrastructure and Brisbane City Plan 2014 data.

To find out more information about flooding and how to prepare visit  flooding in Brisbane .