Floodplain management

There are many low lying areas across the Sunshine Coast Council area and these are associated with the:

• Maroochy River
• Mary River
• Mooloolah River
• Stanley River, as well as
• creek that drain to the Pumicestone Passage.

Floods can occur in low lying areas on a wide range of scales from minor annual events to rare events that can be very severe.

Climate change and sea level rise are expected to increase flood depths in low lying areas and heighten risks in the catchment.

Learning from the past

Extreme flood events have occurred across Queensland in the past. The consequences of these floods having been addressed in the Queensland Floods Commission of Enquiry 2011 (QFCE). There have been many recommendations from the enquiry. This includes best practices also promoted by the organisation Floodplain Management Australia, covering four different kinds of measures:

• land use planning controls i.e. zoning requirements to ensure compatibility between land use and flood risk
• building controls i.e. minimum floor levels and flood proofing
• structural measures i.e. flood mitigation works, and
• flood emergency measures i.e. flood warning, evacuation and recovery plans.

Central to these measures is the need for comprehensive flood studies. These are based on flood modelling using Australian rainfall and runoff data. Such studies by council have resulted in the generation of flood maps and flood hazard mapping.

Council has further considered the recommendations of the Queensland Floods Commission of Inquiry Report 2012 in the Sunshine Coast Planning Scheme 2014 (SCPS 2014). SCPS 2014 sought to ensure that development:

• does not result in the worsening of flood conditions, and
• flood storage and conveyance capacity of low lying areas and waterways is maintained or improved.

This is also reflected in council's Environment and Liveability Strategy 2017. The strategy places importance on the integrity of these areas by stating that:

• low lying areas identified as floodplains are to be protected for their intrinsic:
  • environmental values
  • social values, and
  • economic values.
• development in a flood storage preservation area is to be avoided, unless an overriding need in the public interest is demonstrated with acceptable associated impacts and minimal alteration to the floodplain, and
• development ensures that areas of community isolation are not created.

Flood resilience guidelines

Two guidelines have been developed to assist the community to improve flood resilience:

• existing development
• new development.

The guideline for existing development has been prepared for the benefit of:

• residents
• business owners
• investors
• builders, and
• renovators.

It presents a selection of practical flood resilient building techniques. This guideline also provides advice on what to do during and after a flood event.

It is intended for users who may be:

1. considering the purchase of a potentially flood affected property
2. recovering from a flood event and looking to rebuild and renovate, or
3. looking to better understand their flood risk, so they can make more informed lifestyle and investment decisions.

The guideline for new development has been prepared for those considering new development. Particularly where the development needs to consider SCPS 2014 flood hazard overlay code.

This document uses four development case study sites to demonstrate that the requirements of SCPS 2014:

• are practical for new development, and
• acceptable outcomes are possible.

Height allowance for a dwelling/dual occupancy in low density residential areas affected by flood

The maximum height of a dwelling house/dual occupancy in these areas is measured using a formula. For more detailed information on how to calculate the maximum height allowance, refer to our fact sheet (DOC, 941KB).

More information

Refer to:

• quick guide to living and building low lying areas brochure (PDF, 721KB)
• filling on low lying areas fact sheet (DOCX, 1.4MB), or
• contact council's development services.