Flood information relevant to building works
  • Last updated:
  • 15 Sep 2021

All construction and building work needs to consider the flood hazard area where works will take place. There are special regulations that apply to flood hazard areas. In accordance with the Building Act 1975 and the Building Regulations 2021 Act, council is required to declare a flood hazard area for building regulation purposes. 

Currently, the Planning Scheme Flood Hazard Overlay map is used for this purpose. However, council is proposing to introduce a dedicated Flood Hazard Area for Building Regulation Purposes map.

Flood Hazard Area for Building Regulation Purposes Map

Council is proposing a new Flood Hazard Area for Building Regulation Purposes Map.

Section 8 of the Building Regulation 2021 allows a local government to designate part of its region as a flood hazard area in the following ways:

  • in a planning scheme
  • by a temporary local planning instrument
  • as a resolution.

Designating a Flood Hazard Area for Building Regulation Purposes Map aims to provide the most up to date flood information to help industry professionals delivering and planning development or building works. It helps us to understand how flooding and overland flow may challenge development or building works and design solutions to avoid or work around these challenges.

It also ensures that building certifiers could continue to easily:

  • identify properties that are not mapped as flood affected but are adjacent to flooding so this can be considered when setting floor levels
  • consider flooding associated with drainage
  • understand the location of overland flow paths.

Currently, the designation occurs within the Sunshine Coast Planning Scheme Flood hazard overlay map.

It is proposed to designate the new Flood Hazard Area for Building Regulation Purposes Map through a council resolution.

If endorsed, this would be the first time the building regulation layer has its own map.

This would allow for the mapping to be updated as new data and information becomes available.

The Flood Hazard Area for Building Regulation Purposes Map would be used by industry professionals for building regulation purposes, specifically those who are required to comply with MP3.5 Construction of Buildings in Flood Hazard Areas.

The Flood Hazard Area for Building Regulation Purposes Map is based on the Defined Flood Event, but also includes additional buffer flood hazard areas, that appear within the online mapping at a suburb and property scale. These additional buffer areas incorporate freeboard allowance, overland flow paths and street drainage.

For building regulation purposes, it is important that building certifiers are aware of these elements to avoid any issues relating to overland flow or drainage and ensure that building floor levels include appropriate freeboard allowances.

The Flood Hazard Area for Building Regulation Purposes Map is intended to trigger the request for a Flood Information Search from council, to obtain the flood level, floor level and velocity information relevant to the property.

Understanding and acting on this information helps us all build strong and resilient communities.

How to view the proposed Flood Hazard Area for Building Regulation Purposes Map

The best and easiest way to view the proposed Flood Hazard Area for Building Regulation Purposes Map is via MyMaps.

Once endorsed the new Flood Hazard Area for Building Regulation Purposes Map would also be included in a Development.i property site report instead of the current Flood Extent Map.

Flood Information Search

The Flood Information Search is a paid service that produces a customised flood report for a specific property. It is used to inform the minimum floor level required for building works.

The report is created manually by council staff using best available information, some of which may have been obtained after the last update of public mapping.

Currently, if you are undertaking building works within the Flood Hazard Overlay Map of the Sunshine Coast Planning Scheme, you will need to get a Flood Information Search.
However, if the proposed Flood Hazard Area for Building Regulation Purposes Map is endorsed, this will change. You would then need to get a Flood Information Search if the works were within the Flood Hazard Area for Building Regulation Purposes Map, as it will supersede the Flood Hazard Overlay in the Sunshine Coast Planning Scheme, specifically in relation to Building Regulation purposes.

If the works are accepted development associated with building a new dwelling on the property, then the search will normally be requested by your building certifier. The relevant flood information search option in this situation is the Flood info search – self assess dwelling.

In this situation a flood information search is required because the Building Regulations 2021 require the works are constructed at the regulated floor level elevation and to withstand the forces associated with flooding. The information specified by the Building Regulations 2021 provided on this type of flood information search includes the:

  • defined flood level
  • maximum flow velocity
  • inactive flow or backwater area
  • freeboard
  • finished floor level.

If the works are associated with a development application that is assessable by council, then the relevant flood information search option is Flood info search – all other.

This search is only required if you are advised by the council officer who is the assessment manager for your development application. This search will not include the finished floor level as another planning control may be relevant to the specification of the minimum floor level.

Drainage Deficient Areas

On some properties there are historic drainage problems where the lot may require works to improve the drainage. These lots are referred to as Drainage Deficient and are identified as part of undertaking one of the flood information searches discussed above. If a lot is a declared drainage deficient lot, then additional filling is needed to ensure the lot will drain effectively. This has to occur before constructing a dwelling on that lot. Council will contact you to advise that a Drainage deficient area survey flood information search will also be needed.

The Drainage deficient area survey flood information search provides the survey details of the earthworks required to address the drainage deficiency. This search takes up to 20 working days.

Requesting a Flood Information Search

There are two ways of requesting the above flood information search products from council. These are:

Fees apply for these searches.

Cancellations and refunds

You must submit a request for cancellations (and refund) before the search request is processed.

As the application process is automated, if you would like a refund, it is best to contact the Flooding and Stormwater Management Team directly by email: floodmapping@sunshinecoast.qld.gov.au.

Newsflash subscription

The Flood Information Searches team provides updates about changes to the service. The newsflash service has been designed for Building Certifiers. If you would like to keep up to date with what's new with flood searches, subscribe to receive electronic updates.

Contacts

For more information, or to find out more email us at floodmapping@sunshinecoast.qld.gov.au.