Plan Change 120 and the natural hazard rules

Proposed Plan Change 120 (PC120) to the Auckland Unitary Plan introduced stronger rules for development in areas affected by natural hazards. The natural hazard rules have applied since 3 November 2025, while the rest of the plan change is still going through the submission and decision process.

Background

Auckland Council notified PC120, Housing Intensification and Resilience, on 3 November 2025, with submissions open until 19 December 2025. The plan change deals with housing intensification and with resilience to natural hazards. The council describes the resilience provisions as introducing "stronger rules to make homes and buildings more resilient to the risks of floods and other natural hazards", and as reducing or stopping new development in areas at high risk from flooding, landslides, coastal erosion and coastal inundation.

Rules already in effect

Most proposed plan changes have no effect until decisions are made. PC120 is different. The natural hazard rules, and the rezoning made for natural hazard reasons, have had immediate legal effect since 3 November 2025. They apply to new subdivision, use and development, regardless of whether the zone provides for single houses, terraced housing or apartments.

Applications lodged before 3 November 2025 keep the activity status that applied when they were lodged, but the council assesses them against both the operative Auckland Unitary Plan and the relevant provisions of PC120.

Hazards covered

• Flooding, including flood plains, flood prone areas and overland flow paths.
• Landslides.
• Coastal erosion.
• Coastal inundation.

Effect on development

In the areas of highest risk, development is a non-complying activity. The council has explained that this status gives it "the strongest ability to determine whether development can go ahead". New dwellings in flood plains where the risk is significant are one example. The rules also protect flood plains and overland flow paths from being built over, and some of the most affected areas have been rezoned to the Single House zone.

Landslide susceptibility

The council now uses its landslide susceptibility maps to assess risk when considering resource consent applications in areas that may be prone to landslides. The maps identify areas that may be more prone to landslides. They do not predict landslides, and because detailed site specific information is not available across the region, they cannot reflect every condition on a particular site.

Information needed for an application

A resource consent application for a site subject to natural hazards must include a site specific hazard risk assessment, including any measures proposed to reduce the risk. Depending on the site, this usually involves a geotechnical engineer, a flood or stormwater engineer, or both. The assessment needs to be commissioned early, because its findings can affect the layout and design of the proposal.

Checking whether a property is affected

Flood and coastal hazard information is available in Auckland Council GeoMaps, and the council has published a PC120 map viewer. The maps are a starting point only. Whether the rules apply, and how they apply, depends on the site and the proposal, and should be confirmed before a property is purchased or a design is finalised.

Changes still to come

In February 2026 the Government announced changes to the requirements that apply to PC120, and in July 2026 the council proposed amendments to the plan change. These include stronger natural hazard rules, with additional downzoning in the most vulnerable areas based on updated flood modelling and rainfall data. The council has said it expects to make final decisions on PC120 in mid-2027. Until then, the notified natural hazard rules continue to apply alongside the operative Auckland Unitary Plan.

How RPI can help

RPI can check whether the PC120 natural hazard rules apply to a site before purchase or design, identify the assessments needed, coordinate the engineers, and prepare the resource consent application and the assessment against the PC120 provisions.

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