3 Aug 2017

Year of the flood?

11:21 am on 3 August 2017

Further extreme rainfall is possible this month and most regions will get a "relatively wet" August, according to forecasters.

MetService's outlook for this month shows little reprieve from a year of of torrential rain and flooding.

Record-breaking wet weather last month forced states of emergency to be declared in Otago, Timaru and Christchurch, flooded houses and farmland, and cut power and caused slips in the North Island.

That had followed bitterly cold weather which brought snow to low levels across the South Island, and heavy snow to the lower and central North Island.

After an "extremely volatile" month, August was also likely to be unsettled, according to MetService.

"We expect a relatively wet August for most regions of the country, with further extreme rainfalls possible," said forecaster Georgina Griffiths.

The exceptions were the eastern regions of both islands, and for Southland, where closer to normal monthly rainfall totals are predicted.

"Low pressures, and prevailing northwesterly winds, are likely to be the name of the game during August," said Griffiths.

The first half of the year was one of extreme floods in Bay of Plenty and Auckland.

Heavy rain across the upper North Island in March flooded homes and businesses and caused power cuts.

Flooding at the Kauaeranga River mouth in Thames on 8 March 2017.

Flooding at the Kauaeranga River mouth in Thames in March. Photo: Waikato Rescue Helicopter

Some areas received more rain in two days than normally fell in the entire month.

In eastern Coromandel, Whangamata had 259.8 mm of rainfall in less than 36 hours - more than 150 percent of the normal rainfall for March - while Waihi Beach recorded more than 220mm in 24 hours. That happened about once in 60 years.

Flash flooding ripped through Auckland days later, inundating more than 320 homes throughout the city trapping people in floodwaters on Great North Road in New Lynn.

Worse was to come in Bay of Plenty the following month when the Rangitaiki River burst its banks and a "wall of water" surged through town of Edgecumbe, forcing the evacuation of almost the entire town of 1600 residents.

Tropical storm Cyclone Cook followed, hitting the Bay of Plenty, Gisborne and Hawke's Bay leaving fallen trees and power lines, slips, and road closures in its wake.

Despite the rainy month, slightly warmer temperatures are tipped for most regions, with average to above-average temperatures.

The notable exception is for inland Southland and Otago, where MetService forecast closer to average August temperatures.

Get the RNZ app

for ad-free news and current affairs