Natural hazard means any atmospheric or earth or water related occurrence where the action of the hazard adversely affects or may adversely affect human life, property, or other aspects of the environment. Natural hazards include:
- Volcanic and geothermal activity e.g. geysers.
- Earthquakes and active fault lines.
- Tsunami (tidal wave).
- Seiche wave: a standing wave that oscillates in a lake as a result of seismic or atmospheric disturbances creating huge fluctuations of water levels in just moments.
- Land instability:
- Soil liquefaction
- Soil erosion which can result in landslip and rock fall (includes coastal erosion, bank erosion, and sheet erosion).
- Slope instability and subsidence (e.g. Sinkholes/tomos).
- Falling debris: including soil, rock, snow (avalanche), and ice.
- Inundation: includes flooding, overland flow, storm surge, tidal effects, and ponding).
- Alluvion: The increase of land resulting from the action of water such as sea tides/currents, or river flow.
- Avulsion: A sudden cutting off of land by flood, currents, or change in the course of a river or stream; especially if it separates land from one person’s property and joins it to another’s.
- High Wind Zones
Refusing to grant a building consent
A building consent authority must refuse to grant a building consent for construction of a building, or major alterations to a building, if—
- the land on which the building work is to be carried out is subject or is likely to be subject to 1 or more natural hazards; or
- the building work is likely to accelerate, worsen, or result in a natural hazard on that land or any other property.
But this does not apply if the building consent authority is satisfied that adequate provision has been or will be made to—
- protect the land, building work, or other property from the natural hazard or hazards; or
- restore any damage to that land or other property as a result of the building work.
The building consent authority must assess the risk, and if after assessing the risk, it is satisfied that actions can be taken to remove or mitigate the risk, a building consent can then be granted. If the Council does decide to grant a waiver or modification that will allow a building consent to be granted, it must notify the Register General of Land of the building consent granted.
A risk is determined by assessing the likelihood and consequences of a natural hazard event occurring. Council manages the risk through placing conditions on the issued Resource Consent. The property owner MUST comply with these conditions.
Relevant legislation and additional information
Building Consent Authorities have to register notices when development is proposed on land that is subject to natural hazards; the risk must be managed or mitigated to tolerable levels. Where the risk is high but cannot be managed or mitigated council will not allow building. The risk is determined by a combination of likelihood and consequences. Council manages the risk through the application of conditions on the issued resource consent. These conditions must be met by the property owner.
Refer to the following appropriate legislation:
- Resource Management Act 1991 (RMA)
- S31(1)(b)(i) Functions of Territorial Authorities (i.e. city and district councils)
- Building Act 2004
- Local Government Act 2002
- District Plan
- Civil Defence and Emergency Management Act 2002 s3 Purpose
- Managing Natural Hazard Risk in New Zealand (LGNZ)
With natural hazards Councils are required to:
- Recognise any potential risks, and whether this can be minimized to an acceptable level.
- Take into account any potential risks when making any planning decisions.
- Prevent any new development and activities in high-risk areas especially where the effects cannot be avoided or mitigated.
- Manage community awareness about the planning development of land and natural hazards.