FLOODING LATEST
* The only way north out of Ashburton is by air - 17 roads shut, four bridges damaged and not passable, mayor says.
* Civil Defence orders residents of the low-lying areas of The Pines Beach, Coopers Creek to evacuate.
* State of emergency declared for entire Canterbury region after heavy rain and flooding
* Christchurch residents warned to conserve water over wastewater concerns.
* The Ashburton river is 1m away from bursting its banks, Acting Minister for Emergency Management Kris Faafoi says.
* Ten state highway closures in place throughout Canterbury.
* MetService extends the heavy rain warnings for the region.

People in parts of Canterbury are being ordered to head to higher ground as weather authorities extend a heavy rain warning for the region.

Just after 9am, the Waimakariri District Council issued an "evacuate now" notice on its social media pages.

"Civil Defence requires all residents of the low-lying areas of The Pines Beach, particularly around Dunns Ave, to evacuate now."

Meanwhile, it could be days before flooding recedes in storm-stricken Ashburton.

Rains have pummelled Canterbury over the past 48 hours, with NIWA reporting the wettest regions saw 400 millimetres.

District Mayor Neil Brown said the worst of it's passed for Ashburton.

But Brown says there's still concern the river could breach the stop bank located at the top of the town.

"The river is still full and there is still pressure on there. We haven't taken off the notice for the residents having their bags packed ready to go at short notice."

The following highways are closed:

• Civil Defence: Risk from Canterbury downpours hasn't passed
• 'Incredibly lucky': Farmers rescue people swept away in car
• Canterbury residents taking in the toll of flood damage

State Highway 1 - Burnham to Dunsandel, Temuka between Arowhenua Road and Huirapa Street and Hinds River Brudge from Delamaine Street and Lynnford Road.

State Highway 73 - Springfield to Castle Hill.

State Highway 75 is now closed from Barrys Bay to Birdlings Flat.

State Highway 77 - Darfield to Mount Hutt, Rakaia Gorge to Methven and Glentunnel to Windwhistle.

State Highway 79 - Fairlie to Rangitata.

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The notice said a flood gate is stuck open and areas of The Pines Beach may be flooded as a result.

Anyone who lives on higher sections of The Pines Beach is allowed to stay. But people are warned that they may become isolated for some time if Beach Rd floods.

"The Civil Defence Centre at Rangiora Baptist Church is open for people who need somewhere to stay," the notice read.

Locals are reminded to keep up-to-date via the various community and council Facebook pages - including the Waimakariri District Council Facebook page and website.

It is not yet known when residents will be allowed to return home.

Defence Force personnel have been helping with evacuations and rescues across the region. Photo / NZDF

Heavy rain warnings extended

The heavy rain warning that started on Friday afternoon and was expected to be lifted at 11am today has now been extended over the region.

In Canterbury between Amberley and Geraldine, the warning is in place until 7pm today, MetService said.

"The main focus of heavy rain will be north of the Rakaia River and about the inland hills and ranges, where 50 to 90mm could accumulate until 7pm this evening.

"Away from the ranges 10mm to 40mm is possible in most places, apart from Banks Peninsula where 40mm to 60mm is likely. While for the area about and south of the Rakaia River and north of Geraldine, 30 to 50mm is possible about the foothills until 3pm this afternoon.

"This rain is in addition to the large amount of which has already accumulated for this event, where rainfall totals have exceeded 400mm in some areas.

"The snow level is expected to be around 1500m today, with heavy snow expected above this level."

A further 60mm to 90mm of rain is forecast on top of what has already fallen in the area.

At the Waimakariri Gorge, a car was spotted down a bank nearby.

A number of fire trucks arrived at the scene and firefighters worked to see confirm whether or not someone was inside the vehicle.

Firefighters at Waimakariri Gorge, where a car was spotted. No one was inside. Photo / Hamish Clark

Police officer Mitchel Alatalo said the vehicle was stolen overnight.

He said they have now checked the vehicle which had nobody inside.

A high ropes expert was deployed about 40m down the bank to assess the car.

Meanwhile, the Mackenzie District Council's warning there could be livestock on the loose as river levels fall.

It says fencing may have been washed away, meaning stock may not be contained and wander onto roads.

The council says farmers will be working to address this.

It's also warning debris and gravel in the rivers could cause further damage to bridges.

The ongoing situation comes as residents in Canterbury wake up to a region-wide state of emergency after the weekend's torrential rain caused rivers to burst their banks and forced mass evacuations.

The weather event has been labelled a one-in-100-year event and resulted in a rare red warning being issued by MetService late last week - only the second time such a warning has been put out by the authority.

Heavy rain flooded the region yesterday, closing roads, sparking dramatic helicopter rescues and sending Civil Defence scrambling to set up emergency welfare shelters.

Hundreds of Waimakariri residents were ordered to immediately evacuate their homes last night with stopbanks on two flooded rivers at risk of failing or expected to give way.

Waimakariri District Council ordered residents living near sections of the Eyre and Ashley rivers to leave urgently.

The evacuation order affects 133 properties near the Eyre River and 102 along the Ashley River. Eight households at Kairaki are also being evacuated.

Fire and Emergency personnel were assisting with the emergency evacuations. Affected residents were told stay away from the rivers and surrounding areas until further notice.

And as the Ashburton River rose to dangerous levels, officials warned that up to 4000 people and thousands of homes were at risk if it breached stopbanks.

Sandbagging was underway and the military had been brought in to assist should large scale evacuations be required.

Eight residents were evacuated last night from Geraldine retirement village, and six people tending stock were airlifted to safety yesterday afternoon after being trapped by rising floodwaters at Okuku in North Canterbury.

Ashburton, Selwyn and Timaru all declared states of emergency yesterday before a region-wide state of emergency was declared by Canterbury Civil Defence just before 5pm.

Emergency services had been bracing for the extreme weather, with forecasters predicting "red alert" rain conditions since Friday.

A Fire and Emergency spokesperson said last night their southern communication centre had dealt with around 100 flood-related callouts in the past 12 hours.

"That includes people with water coming into their homes and people needing to be rescued from floodwater, as well as things like power lines brought down by trees."

St John Canterbury district operations manager Curt Ward said staff had established an emergency operations centre in Christchurch and sent additional resources and specialist team members to the area to assist.

Acting Minister for Emergency Management Kris Faafoi addressed media in Ashburton on Sunday afternoon, saying heavy rain was expected to continue overnight and into Monday.

As of Sunday afternoon, the Ashburton River remained a major concern, and Faafoi said the next 24 hours would be critical.

The state of emergency for the Ashburton District has been declared for seven days.

Mayor Neil Brown said "half of Ashburton" would need to be evacuated if the river's stopbanks broke.

But there was "still quite a bit of capacity" in the river.

"We need it to stop raining to let those rivers drop," Brown said.

He said if residents were feeling unsafe they should call 111 or leave if it was safe to do so. But they should stay home if possible and "be cautious when out and about".

Police warned rubberneckers venturing out yesterday to see the flooding to stay home for their own safety and that of emergency workers.

The Ministry of Education said by 7pm last night, 52 of the region's 292 schools, and 24 early learning centres, had confirmed they would close today. Others would decide this morning.

NZTA was monitoring roads and bridges, and a number of state highways in the South Island had been affected by floodwaters.

A state of emergency had been also been declared in Timaru at 11.42am, said Mayor Nigel Bowen.

"We want to give police the powers to force evacuation because we have some people not wanting to move on from specific areas.

"If you're being asked to move, please do so. This particular one was close to a stopbank and ... we just need people to be really sensible in their decision making today."

Two Civil Defence welfare centres have been set up in Geraldine at St Andrew's Hall and the Geraldine High School library.

A local Civil Defence emergency was also declared by Selwyn District Council at 2pm.

"With a declaration in place we will be better placed to manage road closures which are expected across the district throughout today, especially if the state highway network is affected," Selwyn Civil Defence controller Douglas Marshall said.

"We really do urge people to stay off the roads. Travel is likely to be disrupted for some time, and we do not want to see travellers becoming trapped."

Early on Sunday afternoon around 70 residents of Selwyn Huts were asked to "evacuate now" as the rising Selwyn River was expected to cut off access to the settlement.

Meanwhile, Selwyn District Council advised residents of Sheffield, Waddington and Springfield to self-evacuate if they had concerns, as surface flooding affected significant areas of the township.

A notice given to residents said the road would be closed after the evacuation order, and manned until it was safe for residents to return.

Evacuating residents were asked to secure their homes, turn off power, water and gas, and take enough medicines and personal items for two to three nights.

Resident Robby Hyde, who lives in the Upper Huts, said the river was expected to rise up the huts yesterday afternoon.

Of the 70 permanent residents he suspected some would choose to stay behind in spite of the evacuation notice.

"I think a lot of people will go, and a lot will stay, because it's their home," he said.

MetService warned last night that more heavy rain was due to fall on the region till 11am on Monday. Flooding was expected to get worse and more rivers were likely to burst their banks.

It also warned of king tides and large waves, as well as severe gales that were forecast to batter the area.

Canterbury Civil Defence Emergency Management group controller Neville Reilly said officials were "just holding our breath overnight".

"Everything is holding reasonably well but we just can't afford to take chances. There's a lot of contingency planning going on so that if something untoward should happen we are in a position to get people out and give them somewhere to go."