Climate adaptation

Wellington faces an unusual and severe compound hazard profile: high-probability major earthquake risk intersects with climate change impacts including sea-level rise, increased rainfall intensity, and coastal storm surge. These hazards interact: a major earthquake that subsides coastal land permanently increases sea-level-rise exposure; climate-driven flooding may be followed by earthquake-damaged drainage infrastructure.

Sea-level rise threatens significant areas of low-lying Wellington, including Petone Foreshore, Rongotai, parts of Porirua Harbour, and the Hutt River mouth. These areas include key transport infrastructure, residential neighbourhoods, and industrial land on reclaimed harbour margins.

Wellington faces increasing flood risk in low-lying areas of the Hutt Valley and Porirua catchments from both river flooding and urban flash flooding. Climate change is projected to intensify peak rainfall events and increase river flood frequency. Existing flood protection infrastructure was designed to older rainfall standards.

While Wellington's temperate maritime climate provides some natural cooling, urban heat island effects are measurable in the CBD and intensifying with infill development and reduced urban canopy. Vulnerable populations — elderly, infants, those in poorly insulated housing — face growing heat stress risk.