Wellington Declares State of Emergency as Record Flooding Sweeps Through the Capital

Wellington has been placed under a state of emergency after record-breaking rainfall unleashed catastrophic flooding, landslips and displacement across suburbs from Mount Cook to Owhiro Bay, with red weather warnings remaining in force through Tuesday night.

The Wellington Civil Defence Emergency Management group declared the emergency at 5.25pm on Monday, following an extraordinary overnight deluge that saw more than 70 millimetres of rain fall in a single hour across parts of southern Wellington — more than half the rainfall the city’s Botanical Gardens typically receives across the entire month of April. Over a 48-hour window, precipitation totals nearly tripled monthly averages, with many long-term Wellingtonians describing it as the worst flooding they had witnessed since the devastating 1976 storm.

WCEM controller Carrie McKenzie said residents should not wait for official instructions before acting. “The priority is life safety. We are asking people to take this seriously,” she said. MetService reinforced the severity of the situation, warning of a “threat to life from dangerous river conditions, significant flooding and slips.”

Wellington fire crews had already responded to nearly 200 weather-related callouts between 2am and 4.30pm on Monday alone. Fire and Emergency New Zealand deployed specialist rescue teams to the region, stationing up to 20 personnel with enhanced water rescue capabilities across the Hutt Valley and Wairarapa as rivers continued to rise through the day and into the evening.

The damage across suburbs was extensive and in some cases extraordinary. In Vogeltown, a house on Liardet Street partially collapsed after a hillside slip undercut its foundations, leaving the structure dangling at the edge of an unstable slope. In Mount Cook, dozens of cars were left floating in floodwaters as streets became rivers. At Owhiro Bay, at least one vehicle was swept roughly 150 metres along Happy Valley Road and into the tide. Landslips tore through sections of Balfour Street in Mornington, while Island Bay, Berhampore, Newtown, Brooklyn and the Basin Reserve area all recorded significant surface flooding and road closures.

A search and rescue operation was also under way in Karori, where a man was reported missing from his flood-affected home, adding to the gravity of an already serious situation.

State highways across the region were closed or disrupted, and Metlink suspended services on multiple routes as conditions deteriorated. Emergency hubs were established in Lower Hutt to provide shelter and support for residents displaced from their homes, including elderly and disabled people who required assistance evacuating.

Red heavy rain warnings remained active as of Tuesday morning, with the Wellington region excluding Porirua facing ongoing risk until 9pm Tuesday and the Wairarapa under warning until midnight. MetService was forecasting up to a further 150 millimetres of rainfall over the 24 to 36 hours from Monday afternoon, meaning the worst may not be over for many communities still dealing with the aftermath of the initial event.

Scientists and meteorologists have sought to explain why this particular storm caused such widespread destruction despite advance warning of severe weather risk. The system developed as a large, slow-moving low-pressure system originating in the Southern Ocean, drawing cold air northward over an unusually warm Tasman Sea. That combination generated widespread convection and localised thunderstorm clusters capable of dumping enormous quantities of rain onto small areas in very short timeframes. Wellington’s vulnerability was compounded by pre-saturated ground from Cyclone Vaianu, which passed through the region only a week prior, leaving soils with little capacity to absorb further rainfall.

Professor James Renwick, a climate scientist at Victoria University of Wellington, noted that the storm’s “clusters of thunderstorms producing heavy, localised downpours” made precise prediction of the worst-affected areas extremely difficult, even with reliable advance warning that a dangerous event was coming. The fine-scale atmospheric dynamics driving such rainfall operate at the scale of kilometres or less, well below what conventional forecasting models can capture in detail.

The Wellington event is one of a series of weather emergencies to strike the North Island within days. States of local emergency were also declared in the Whanganui District and the Ohura ward of the Manawatu-Whanganui region on Sunday, following overnight flooding, landslips and state highway closures in that area.

Researchers have long warned that events of this kind are likely to become more frequent and more intense as the climate warms. Warmer oceans and a warmer atmosphere hold more moisture, fuelling heavier rainfall when storm systems develop. Modelling projects that one-to-three-day rainfall intensity in New Zealand could increase by between 10 and 20 percent by mid-century under mid-range emissions scenarios, meaning the scale of disruption Wellington experienced this week may come to represent a new normal rather than an exceptional event.

For now, residents across Wellington and the Wairarapa were urged to stay home if possible, avoid all floodwaters, and monitor MetService and RNZ for updates. Civil Defence advised that residents in low-lying and flood-prone areas should evacuate without waiting for a formal instruction to do so.

RNZ’s coverage of the state of emergency declaration and analysis of what made the storm so intense provide further background on the event and its causes.

If you are in Wellington or the Wairarapa and have been affected by the flooding, share your experience in the comments below.