Before you start planning your project you will want to check if the land may be subject to natural hazards. These include the likes of erosion, inundation, and wildfire.

How do I find out if my land is subject to a natural hazard?

If there are any potential natural hazards on your property this information may be on your

So what is a natural hazard?

Natural hazard under Building Act sections 71 to 73 means any of the following:

  • erosion (including coastal erosion, bank erosion and sheet erosion)
  • falling debris (including soil, rock, snow and ice)
  • subsidence
  • inundation (including flooding, overland flow, storm surge, tidal effects and ponding)
  • slippage.

For a building consent the above hazards have a specific process under the Building Act. Other hazards may be recognised by the Resource Management Act, or exist generally, but these do not have specific Building Act process requirements.


Wildfire risk is a natural hazard that has been identified in the proposed district plan. If you’re in or near a rural area, it’s wise to be fire smart and protect your home and property from the threat of rural fire.

See Fire and Emergency New Zealand’s information protecting your home Wildfire Safer Housing Guide.

Flooding and coastal inundation?

Most of us are aware that in Selwyn most of us live on a big floodplain. This means land and homes in the district tend to be at risk of flooding from rivers, local runoff or coastal inundation.

When a building consent application is submitted for a new building or alteration, our role is to assess the likelihood of flooding of the land not entering buildings under section 72 of the Building Act. We assess this

  • using mapping available to us from Canterbury Maps showing previous flooding along with areas that may be susceptible to inundation, and
  • factoring in all other legislation, including the proposed District Plan which has a consideration for properties identified in a 1:200 year flood event.

You can check Selwyn's flooding and coastal hazard details on Canterbury Maps.

Will a natural hazard affect my ability to get a building consent?

A building consent will still be granted if we decide that your proposed work will not accelerate, worsen or result in a natural hazard on your or other property.

If your property is identified as subject to a natural hazard:

  • You may be asked to provide a Flood Hazard Assessment with your consent application (if flooding is the natural hazard identified).
  • Other hazards may also require specialist reports that identify the extent of the hazards and make recommendations for building consent requirements.
  • You may need to design to protect the building from the effects of the hazard or alternatively in some cases you may have to apply for, and justify, a waiver or modification to the building code in connection to the natural hazard.
  • When applying for building consent where a natural hazard affects the building you’ll need to confirm that you understand the potential effects the identified hazard may have on your insurance and any future sales, and that you are aware that you should seek legal advice.
  • A section 73 notification will be registered on the property title via Land Information New Zealand (LINZ), with a fee payable for notifying this to LINZ.

We’ll let you know if your application is being considered under section 72 when we process your application.

You can still withdraw your building consent application at this stage if you decide to not go ahead with your project. There will still be costs to pay for time already spent processing your application to that point in the process.

What is a section 73 notification and how does it affect my property?

A section 73 on your Record of Title

  • identifies and registers what the natural hazard is on your land,
  • warns future property owners of the natural hazard, and
  • means that if the building is subsequently damaged by a hazard event, the owner and subsequent owners cannot claim against the Council for issuing the building consent.

Therefore a section 73 may affect:

  • the value of the property,
  • your insurance cover for the building, and
  • EQC cover.

We advise you to contact your solicitor, insurance company, and the Earthquake Commission if you are either purchasing a property in these hazard mapped areas and/or you are intending to carry out any new building or alterations/additions in the future.