Lower North Island and Marlborough, 2004
Between 14 and 17 February 2004, intense rain (up to 300 millimetres in two days) fell on land already saturated after previous severe weather. Worst affected were rivers in the South Taranaki, Manawatū–Whanganui, Wellington and Marlborough areas. The Manawatū River peaked at its second-highest level on record. Many rivers breached their banks, spilling silt-laden flood water through towns and across farmland. A number of rural communities had to be evacuated, and at the height of the emergency about 2,300 people had to leave their homes and farms.
About half the roads in the Manawatū–Whanganui region were closed and more than 20 bridges were damaged. The civil defence operation was the largest in 20 years, with air force helicopters rescuing stranded people and dropping supplies to communities cut off by flood waters.
In Marlborough, in the upper South Island, the Waitohi River flooded parts of Picton, and 500 people were evacuated for fear an overflowing water supply dam might collapse.
The February floods cost over $112 million in insurance payouts, and the government granted $135 million in aid to farmers. Around 2,600 farmers were affected by the flooding, with some having to abandon farming their properties. The total economic impact was estimated to be about $400 million.
Eastern Bay of Plenty, 2004
In July 2004, the eastern Bay of Plenty was extensively flooded when a frontal system stalled over the area, causing prolonged and intense rain. The Whakatāne River spilled into Whakatāne’s central business district and the Awatapu area. Water had to be released into the Rangitāiki River from the Matahina Dam to prevent the dam from bursting. The Rangitāiki overflowed above Edgecumbe, creating a 100-metre-wide breach in its stopbanks. Flood waters entered Te Teko and Edgecumbe, and swamped some 17,000 hectares of farmland.
At the height of the floods, about 3,200 people had to leave their homes, many sheltering in evacuation centres and on local marae. A swarm of shallow earthquakes north-east of Rotorua added to the misery, triggering many landslides on saturated hillsides. In all, more than 450 farms were affected by the floods, with over 200 homes made uninhabitable.
Cyclone Debbie and Cyclone Cook, 2017
In April 2017, within a week of each other, remnants of two tropical cyclones, Debbie and Cook, passed over New Zealand. Cyclone Debbie dumped up to three times the normal April rainfall in three days on some areas. The Rangitāiki River rose due to the heavy rain, and on 6 April a section of river stopbank at Edgecumbe gave way. A torrent of water abruptly flooded into the town and inhabitants had just a few minutes to flee their homes. Many were marooned and had to be rescued by boats, tractors and trailers. In all about 2,000 people were evacuated from the town. In the South Island, Kaikōura was cut off as State Highway 1 south of the town was blocked by mudslides washed down from loose landslide debris from the November 2016 Kaikōura earthquake.
Rain from Cyclone Cook remnants caused flooding, slips and power outages along the North Island east coast. Hard hit areas included the Thames-Coromandel District, Matamata, Tauranga, Whakatane, and parts of Hawke’s Bay.