Backflow

During the January 2011 flood, parts of Brisbane may have been affected by water which came up from the river through the drainage networks and into our streets. This is referred to as backflow flooding.

Initial investigations have been completed for the assessment of backflow flooding experienced in the January 2011 flood, and Brisbane City Council will continue to investigate the feasibility of backflow prevention measures.

A backflow device limits water from high tides or river flood events entering stormwater systems and is one of many flood mitigation tools and strategies that Council is considering to help protect Brisbane from the impacts of river flooding.

Investigations into backflow

Council is using past flood information to ensure the city is better prepared in the future. Technical investigations have utilised data gathered from the January 2011 flood to identify potential opportunities for the application of backflow prevention measures.

The first stage of the backflow investigation examined three case study areas; New Farm, Milton and the Central Business District. These case study areas were chosen because they have a diverse mix of land use and had a large number of people affected by flooding in January 2011.

The citywide desktop review identified 39 sites for further investigation. The backflow analysis for these sites began in November 2011 and is due for completion in May 2012. After Council has reviewed the report from the second stage of this investigation, a program of works for other locations across the city is expected to be announced mid 2012.

Backflow prevention devices might not be suitable in all situations which is why additional assessment work needs to be undertaken.

Current situation

The installation of three backflow devices in the Moray Street drainage system in New Farm have been completed and works have commenced to install four backflow devices in the Cribb Street drainage system in Milton. The Cribb Street drainage system service parts of Cribb Street, Crombie Street, Walsh Street, Manning Street, Railway Terrace, Park Road and McDougall Street.

The Lord Mayor recently announced the installation of backflow devices in Alice Street, Charlotte Street and Margaret Street in the Brisbane CBD in the coming months.

Council is currently conducting further technical investigations across 39 sites in Brisbane affected by backflow flooding. This report is due in May 2012. An ongoing program of works for other feasible locations across Brisbane will be announced after this time.

While flooding is a natural part of living in Brisbane, Council is committed to minimising the impacts of flooding on our city. Backflow devices are one of many flood mitigation tools Council is applying to help protect Brisbane.

There will be some impacts during construction including:

• the installation of devices for the Cribb Street drainage system will require a temporary partial closure of the Bicentennial Bikeway. Signs and traffic controllers will be in place to help pedestrians and cyclists through this area
• construction at each location will take approximately four weeks
• timing of construction will be dependent on tides
• night works will be kept to a minimum where possible
• residents in close proximity to the works will be notified in advance of any impacts

Consultant reports

Download the consultant reports:

• MWA Backflow Report Volume 1 - Executive Summary (PDF - 3.1Mb)*
• MWA Backflow Report Volume 1 - Part 2 (PDF - 1Mb)*
• MWA Backflow Report Volume 1 - Part 3 (PDF - 2Mb)*
• MWA Backflow Report Volume 1 - Part 4 (PDF - 1.5Mb)*
• MWA Backflow Report Volume 1 - Part 5 (PDF - 2.8Mb)*
• MWA Backflow Report Volume 1 - Part 6 (PDF - 1.7Mb)*
• MWA Backflow Report Volume 1 - Part 7 (PDF - 4.1Mb)*
• MWA Backflow Report Volume 1 - Part 8 (PDF - 1Mb)*
• MWA Backflow Report Volume 2 - Attachments Part 1 (PDF - 1.4Mb)*
• MWA Backflow Report Volume 2 - Attachments Part 2 (PDF - 1Mb)*
• MWA Backflow Report Volume 2 - Attachments Part 3 (PDF - 5Mb)*
• MWA Backflow Report Volume 2 - Attachments Part 4 (PDF - 580kb)
• MWA Backflow Report Volume 2 - Attachments Part 5 (PDF - 920kb)
  
  

More information

For more information, you can:

• download the November Backflow flooding investigation fact sheet (PDF - 670kb)
• phone the Backflow Project Team during business hours on 1800 884 681
• phone Council on 07 3403 8888
• email the Backflow Project Team
• write to:
  Backflow Project
  City Projects Office
  Brisbane City Council
  GPO Box 1434
  Brisbane Qld 4001