Flood information relevant to building works

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.

On 21 September 2023 council designated a flood hazard area for building regulation purposes map through a council resolution. This designation supersedes the designation within the Sunshine Coast planning scheme.

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.

Adopting the flood hazard area for building regulation purposes map through a council resolution, as a separate map outside of the planning scheme, enables the mapping to be updated a new data and information becomes available.

The flood hazard area for building regulation purposes map is to 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 flood hazard area for building regulation purposes map

The best and easiest way to view the flood hazard area for building regulation purposes map is via Development.i site report.

MyMaps - flood mapping

Please refer to the downloadable guide and how-to video to help you navigate the flood maps.

How to view flood hazard area for building regulation purposes map (PDF, 2736KB).

Register of flood hazard areas

In accordance with Section 4 of the Building Regulation 2021, the following is a register of each flood hazard area designated by council.

Date	Reference
21/09/2023	Version 1. Resolution: OM23/99
21/05/2014	Sunshine Coast Planning Scheme 2014. Table 1.6.1 (Building Assessment Provisions) and Schedule 2 Flood hazard overlay maps OVM1G -OVM55G
16/03/2008	Maroochy Plan 2000 Regulatory Map 1.5 Flood Prone and Drainage Constrained Areas Caloundra City Plan 2004 Flood Management Overlay

Flood information search

The purpose of a flood information search is to provide the information required by the Building Regulations 2021 when building works are proposed within the flood hazard area for building regulation purposes. A (self-assessable) flood information search provides the:

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

For simple situations where a property flood information search can be automated, the relevant information for MP 3.5 Construction of Buildings in Flood Hazard Areas is provided on the Development.i site report, tabulated under the flood hazard area for building regulation purposes map.

For more complex situations where the flood search is unable to be automated, a manually created Flood Information Search will be required. This is a paid service and provides a customised flood report for a specific property using best available information, some of which may have been obtained after the last update of public mapping.

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.

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:

a property search application
using MyCouncil online services.

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: [email protected].

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.