The 2023 Auckland Anniversary weekend storm: An initial assessment and implications for the infrastructure system

As part of our work to understand resilience in infrastructure, Te Waihanga has undertaken an initial infrastructure assessment of the 2023 Auckland Anniversary weekend storm.

About this work

The purpose of this paper is to provide an initial view on:

  • the severity of the January 2023 Auckland Anniversary weekend storm resulting in
    stormwater flooding in Auckland
  • the impact of the storm on Auckland’s infrastructure
  • the issues or weaknesses this event has raised about stormwater management and our
    infrastructure system.

Please note that this paper:

  • is not intended to provide a full assessment of the impact of the flooding on Auckland, and
    does not comment on the impact on areas outside of Auckland
  • was compiled in the days immediately following the storm, using the limited public
    information available at the time, meaning that we are necessarily relying on secondary
    sources of information
  • was written before Cyclone Gabrielle reached New Zealand and so refers only to the
    Auckland Anniversary weekend storm.

Key points

  • The January 2023 Auckland Anniversary weekend storm was an extreme rainfall
    event by any measure.
  • Auckland’s economic infrastructure appears to have suffered brief and localised
    loss of service in most cases. Serious and prolonged outages were not widespread
    and were largely due to landslides rather than flooding.
  • Responsibilities for stormwater are fragmented and design standards vary.
  • Alignment of stormwater management and land use planning is important, with
    implications for institutional design.
  • Interdependencies between infrastructure networks matter for resilience.
  • There is a more fundamental discussion to be had about infrastructure in the face
    of climate change.


As part of our work to understand the Auckland Anniversary weekend storm Te Waihanga Principal Advisor - Strategy Nik Green recently spoke to Senior Advisor - Delivery Christian Gamst about stormwater and resilience.