Local Government New Zealand National Sea Level Rise Exposure Survey

Project overview

The vulnerability of billions of dollars’ worth of critical local government infrastructure assets to sea level rise has long been shrouded in theory and debate. For the first time, the report “VULNERABLE: The quantum of local government infrastructure exposed to sea level rise” not only laid bare that exposure and its future impacts in real world terms, but also delivered a platform on which to create a more resilient future. While exposure to sea level rise may not result in catastrophic failure or loss, it may mean loss of service and/or effectiveness and this can extend landward of the exposure area. Tonkin + Taylor T+T) assisted LGNZ in the preparation of the report by undertaking council surveys, amassing and extrapolating data and providing technical support.

Services provided

This project involved an assessment of the quantum and value of local government-owned infrastructure exposed to various increments of sea level rise. The project culminated in LGNZ releasing the report “Vulnerable”. The project involved a number of key phases: 

  • Circulation of SLR polygons (from NIWA) and a detailed reporting template to all coastal Councils in New Zealand (62 in total) 
  • Receipt of data for 3 waters, roads, buildings/facilities and greenspace, relating to both quantity and replacement and/or depreciated value
  • Aggregation and summary of the data in various forms and preparation of maps and infographics to summarise findings
  • Assistance provided to LGNZ with reporting

T+T is also assisting LGNZ with preparing a guidance document for the local government sector, which will allow infrastructure and asset owners to examine their assets and plan strategically.


  • This project has significant relevance to all local and central Government entities, as well as private owners of key utilities infrastructure: 
  • It delivers a comprehensive and broad assessment of climate change related sea level rise, involving changing risk profiles 
  • It involves impacts to infrastructure, including transport infrastructure 
  • It is a national level assessment
  • While interdependencies were not explicitly considered, they were discussed in many facets – including where impacted roads may adversely impact access to other infrastructure locations, lifeline utilities or to communities themselves
  • The project involved an assessment of exposure using geospatial tools. This can then be easily developed into a more comprehensive assessment of risk by including consequence/criticality and asset vulnerability.

Key Personnel

Richard Reinen-Hamill

James Hughes

Morgan Lindsay

Rebekah Robertson 

Download Capability PDF