By Julia Gabel
A local state of emergency has been declared in Timaru following ongoing heavy rainfall.
Timaru residents have been issued an evacuation notice after a one-in-20-year flooding event of the Rangitata River has blocked State Highway 1.
The Timaru District Council has asked all residents between McLelland, Orion Rangitata Mouth Roads and Rangitata River to evacuate immediately.
The main highway through the West Coast has also been blocked off meaning all road routes between Christchurch and Dunedin will be closed until at least tomorrow.
Timaru Emergency Operations Centre's Steven Doran said the flood event is causing "quite significant issues".
"There's been significant rainfall in the headwaters of the Rangitata River, that's basically creating a big bulge of water coming down the river. We're expecting that to peak around 7pm tonight," Doran said.
"It's in a rural area so there's not the same sort of risk to property but it has cut off two main arterial routes.
Part of SH1 and the Rangitata Bridge is closed due to the rising river level, as well as the back up Arundel Bridge.
The Rangitata River is currently flowing at around 2265 cumecs and extreme flows, likely 3000 cumecs or more, are anticipated later today.
Doran said the water coming down the headlands of the Rangitata River has peaked at 2700 cubic metres per second.
"There is water coming down the river at a level we wouldn't expect to see for at least 20 years between times," Doran said.
"And the river usually runs at about 300 so it's a big big difference. It's a braided river so it doesn't always flow in the same path as well. So it can change path and a lot of farmland can be in the way as well."
Timaru District Council says there is no way to cross the Rangitata River and no alternate routes.
Campers in the area have been told to evacuate immediately.
People in Rangitata township and hut holders are also being told to be ready to evacuate at short notice.
State Highway 6 on the South Island's West coast is closed from Hokitika down to Makarora, with several slips on the road. A damaged bridge near Te Taho is being assessed.
Meanwhile, Auckland is expected to be hit with heavy rain and possibly severe thunderstorms and hail later today.
Parts of Northland, Great Barrier and Coromandel are also in line for heavy downfalls.
Showers are expected this afternoon, and residents are being warned of the possibility of slips and flash flooding in low-lying areas.
Heavy rain is expected to lash other parts of the country later today as well.
Hokitika and Westland are already feeling the brunt of bad weather.
Haast, Fox Glacier and Franz Joseph have all been cut off after part of a bridge on State Highway 6 near Te Taho collapsed in heavy rain overnight.
Extensive rain and strong winds have been battering the region, and several weather warnings are still in place.
West Coast Civil Defence Emergency Management Group's Simon Bastion says it is going to cause a lot of disruption for locals and motorists.
He says there are no detours available for that highway, so people will have to wait until it is repaired. Power is still out in the Fox Glacier area.
State Highway 6 Haast to Makarora and from Fox Glacier to Haast are also closed.
Power supplies in some areas of Fox Glacier have been disrupted, and Franz and Fox Glacier residents are asked to conserve water on public supply lines.
Meanwhile, Queenstown Lakes District Council staff and contractors are continuing to respond to high lake levels in and around Wānaka and Queenstown in line with the latest modelling and the local situation.
"Ongoing precautionary measures include debris clearance on both lakefronts with some 40 truckloads of driftwood removed from Wānaka alone yesterday," the council said.
Wastewater remains isolated on Ardmore Street and lower Helwick Street in Wānaka. A small additional area of the Wānaka CBD will have its wastewater services turned off from midday today as a precaution to protect the network in case of further lake level rises.
There is some restricted pedestrian access in specific areas close to the Wānaka lakefront.
A 130m-long concrete block wall was completed at Queenstown Bay yesterday afternoon. This is to protect the nearby pump station and Bathhouse Café from wave action.
More sand and a further 1000 sandbags will be delivered to Queenstown today.
The Otago Regional Council (ORC) and QLDC are continuing to monitor lake and river levels, and are prepared to implement local road closures in affected areas if necessary.
QLDC harbour master Marty Black reiterated yesterday's warning about swollen rivers and significant risk due to the possibility of floating debris and submerged structures.
There is a heavy weather forecast for Hokitika. Thunderstorms are also approaching Greymouth, Kumara, Shantytown, Ross, Kokatahi, Kowhitirangi and Lake Kaniere.
Lighting, hail and torrential rain are expected in those areas.
A severe thunderstorm watch remains in force for Nelson, Buller, Westland and the Canterbury high country.
Canterbury is being warned of strong winds that could reach up to 120 kmh, while heavy rain is expected in parts of the area.
Heavy rain is expected in the Taranaki area from this evening, and in the central North Island from tomorrow.
In the capital city, winds could reach severe gales in exposed places.
In the lower south west, heavy rain is also expected in Fiordland and Doubtful Sound.