HOW TO STOP BUILDING IN NATURAL HAZARD AREAS

S. Wharton FEngNZ BE(Env) (Whangarei District Council)

ABSTRACT

How could buildings be allowed in dangerous flood areas or on unstable cliffs? Why are new developments still being built in natural hazard areas and what can be done about it?

It has taken multiple severe hazard events in 2023 which sadly caused loss of life and property, with serious financial consequences, for these questions to gain traction with media and politicians.

All the necessary tools to stop development in natural hazard areas already exist within the regulatory regime of the Local Government Act 2002, Resource Management Act 1991 (RMA), Building Act 2004, and NZS3604 NZ Building Code. With RMA Reform and Three Waters Reform legislation being repealed, engineers need to find better ways to work within the current legislation and to communicate natural hazard risks.

There are many multi-faceted reasons why consents are still being granted within natural hazard areas across the country, including:

• The suite of legislation is complex and interdependent
• Many elements need to be in place and understood across various professions for the system to work effectively
• There is no standard nation-wide approach to defining natural hazards, resulting in each Council defining hazards differently (eg using 1%AEP or 2%AEP flood events)
• Political will is often low when it comes to flagging properties as potentially subject to a natural hazard due to backlash from ratepayers
• Environment Court judges, RMA planners, and building consent managers often ignore or override the engineer’s advice to ‘avoid’ the hazard, believing instead that it should be possible to ‘mitigate’ in any circumstance
• Poorly defined roles and differing approaches create an uncomfortable conflict zone within the RMA and Building Act regulatory regimes
• Human nature drives many aspects of the process down a dangerous route. Comments such as ‘I’ve lived here 30 years and I’ve never seen a flood that high.’ indicate an unwillingness to believe the expert’s predictive flood models, catchment planning work, and geotechnical reports done to identify hazards.

Due to the integral connection between surface water and land stability, the onus is on the stormwater and geotechnical professionals collectively to improve the approach to natural hazard identification and communication. A cohesive multi-disciplinary approach is required to improve the assessments made for District Plans, resource consents, and building consents. Without change, the total liability for New Zealand will only increase.

Attitudes towards natural hazards have changed significantly during 2023. The public better understand that it is simply not safe for people to live in certain areas. The insurance industry is also driving change by shifting risk. A window of opportunity exists where there is willingness to change the system to avoid a repeat of the tragic events in Auckland and Hawke’s Bay.

Councils have a duty of care in assessing natural hazards and consents which creates long term liability. The potential quantum of liability from granting consents in high risk natural hazard areas needs to be better understood.

This paper provides a roadmap for stopping development in high risk natural hazard areas that can be implemented right now.