Waiho Bridge destroyed as extremely heavy rain hits New Zealand’s South Island

Heavy rain over the past 2 days caused near-record river levels across the West Coast of New Zealand's South Island. In less than 48 hours, parts of the region recorded 548 mm (21.6 inches) of rain, nearly 10% of its yearly average. More than 300 mm (11.8 inches) of rain fell in just 24 hours. Up to 800 mm (31.5 inches) are expected in the West Coast ranges before the event is over.

The Waiho Bridge was destroyed by the rising and rough floodwaters of the Waiho River near Franz Josef on March 26, forcing authorities to declare a State of Emergency for the Westland District.

According to the New Zealand Transport Agency (NZTA), hours of torrential flood waters carrying large amounts of rock and material downstream battered the bridge's support piers until it collapsed.

One of the residents said he warned authorities about three days ago that the northern end of the bridge's abutment was missing rocks and needed strengthening.  

The Haast River neared a high-level mark but leveled off at 7.6 m (24.9 feet), NZ Herald reports. However, the Hokitika River continues to rise, sitting at 5 m (16.4 feet) currently.

Westland Mayor Bruce Smith told Newstalk ZB heavy rain was at the base of their problems but people remain the focus of the council and Civil Defence.

"This is a 100-year event, there is a huge amount of rain… I haven't seen all of the rivers impacted in Westland at exactly the same time," he said.

The NZ Transport Agency reports State Highway 6 has been closed in numerous locations between Makarora near Wanaka and Hokitika on the West Coast.

Civil Defence West Coast said there has been minor breaches from the Haast River into some properties, and accordingly, a Welfare Centre has been opened in the Haast Hall. Displaced persons are advised to go to the Welfare Centre in the Haast Hall for assistance.

There is localized flooding at Palmers Creek, south side of the Arahura River, and the Blue Spur Road is currently impassable in places.

SH6 is closed from Hokitika to Makarora with a slip at Douglas Falls in the Haast Pass, yet to be assessed.

SH73 – the road is now closed at Candy’s Creek at Arthurs Pass.

The carpark at the Hokitika Gorge has been temporarily closed.

Ritchies Bus Services have suspended all bus services tomorrow (Wednesday) for the whole of the West Coast.

Police are advising members of the public to avoid traveling due to the weather throughout the night.

Unfortunately, we've had to close part of Glenorchy-Paradise Road at Diamond Lake (pictured). Wanaka-Mt Aspiring Road and Kinloch Road remain closed.  credit goes to our Downer road crews. pic.twitter.com/JKDwoffxpe

— QLDC (@QueenstownLakes) March 26, 2019

A strong and moist northwest flow covers the South Island ahead of an active front over the south of the South Island, NZ Met Service warns. This front moves north over the South Island overnight Tuesday and Wednesday morning, then weakens over the North Island from Wednesday afternoon.

The front has already delivered a significant amount of heavy rain to southern Westland, Fiordland, and the headwaters of the south Canterbury and Otago Lakes and Rivers.

Heavy Rain Warnings are still in force Westland, Buller, the Canterbury headwaters. In addition, Strong Wind Warnings are in force for Canterbury High Country, Wellington and Wairarapa from Featherston southwards.

People are advised to keep up to date with forecasts in case additional areas are added to the Warning.

Featured image credit: Jacob Schonberger