Cyclone, storm surge and riverine flooding building and development standards

This page has information for people living and building in areas of the Northern Territory (NT) that are affected by major natural hazards.

Cyclone areas

Buildings in cyclone-prone areas of the NT built after Cyclone Tracy in 1974 should meet the new building codes and be able to withstand mid-range category 4 cyclones with wind speeds between 225 to 279 kilometres per hour.

No building is completely cyclone-proof and even a building constructed to code could sustain significant damage from wind-borne debris in even a low-category cyclone.

Read more about cyclone emergencies, including how to prepare your home and making evacuation plans. 

You can also get the brochure Is your house prepared for a cyclone?.

Storm surge areas

A storm surge is a rise above the normal high-tide water level caused by strong onshore winds or atmospheric pressure. 

If your building is along the NT coast it may be flooded when tide levels rise in a storm surge caused by a cyclone.

Storm surges can flood low-lying areas several kilometres inland.

Human development alters the shape of the ground and climate conditions change over time. If flooding has not previously occurred in your area it does not mean it will not happen in the future.

Checking storm surge maps

Read more about storm surges, and check a map to see if your property is in storm surge area.

Storm surge maps do not show the height of possible storm surges.

For more information about storm surge heights, phone the Department of Land Resource Management on (08) 8999 4455 or email water.dlrm@nt.gov.au.

Building and developing in a storm surge area

You should avoid building a house or essential community service in primary and secondary storm surge areas.

These areas are appropriate for open space, recreation, and non-essential public facilities. Some industrial and commercial land uses may be allowed in a secondary storm surge area.

A development permit is required if you wish to develop in a primary storm surge area. Any previously approved compliant development or building on the property remains approved.

New developments must also meet all necessary development requirements. They must be designed to ensure personal safety is preserved, buildings are protected, and impacts on neighbouring properties are minimised.

New habitable rooms added to existing houses in storm surge areas must be built 300mm above the identified primary storm surge level. This does not include bathrooms, laundries, toilets and other rooms not frequently occupied.

Read more about developing in a storm surge area in the following parts of the Northern Territory Planning Scheme:

  • part 4, clause 6.14 - about land subject to flooding and storm surge
  • part 5, clause 11.4.1 - about site characteristics in subdivisions of rural or unzoned land for lots of one hectare or greater.

Before applying for a development permit you can make a free appointment with a planner using the Development One Stop Shop.

You must have building approval to develop in a declared building control area. Read about work that requires permits.

Insurance in a storm surge area

Several insurance companies offer storm surge damage cover. 

Check your current policy and note any exclusions.

Riverine flood areas

Riverine flooding occurs in the NT when heavy rainfall causes relatively high water levels in rivers or creeks to break their banks.

Read about flood emergencies. 

Checking floodplain maps

Check if your property is in a flood-prone area. 

Read about floodplains and get maps of areas of possible and probable flooding in the NT.

Building and developing in a flood-prone area

Development is restricted where there is a 1% or greater chance of flooding in a year. 

New developments in a defined flood area must have a development permit and meet all necessary development requirements. They must be designed to ensure personal safety is preserved, buildings are protected and impact on neighbouring properties is minimised.

The floor levels of your habitable rooms must be at least 300mm above the flood level for the site. You should not use fill to achieve required floor levels. 

You should also avoid storing or disposing of environmentally hazardous industrial material in flood-prone areas.

Read more about developing in a defined flood area in the following parts of the Northern Territory Planning Scheme:

  • part 4, clause 6.14 - about land subject to flooding and storm surge
  • part 5, clause 11.4.1 - about site characteristics in subdivisions of rural or unzoned land for lots of one hectare or greater.

Before applying for a development permit you can make a free appointment with a planner using the Development One Stop Shop.

You must have building approval for work in a declared building control area. Read about work that requires permits.

Last updated: 13 November 2017