Christchurch residents criticise council's storm response

Residents in Shirley move their belongings out of their flooded homes in Christchurch, New Zealand. Photo / Martin Hunter

Lianne Dalziel says for some Christchurch residents the once-in-a-century storm could be the last straw.

Hundreds of Cantabrians remain without power this morning as the Christchurch mayor defends the council's response to widespread flooding.

Metre-high floods cut off some homes and forced the evacuation of others in what the council says was a once-in-a-century storm.

Energy provider Orion said that by 10am, around 700 customers were still without power, mostly around Banks Peninsula but also parts of Christchurch and an area around Southbridge.

Flooding, slips and water-logged ground in the hills was preventing access to the network or making repairs difficult, it said.

Image 1 of 8: Flooding at Somes Rd Lyttelton. Photo / Daniel Blake

Christchurch residents have criticised the council over its response to the storm, with some saying the council knew about the flood risks but did not respond adequately with sandbags.

Mayor Lianne Dalziel this morning said the council was caught out by the scale of the event. The initial forecast was for a one-in-five-year-event, but it later grew to a one-in-a-century event.

"Yes we were caught out by the scale of the event," she told Radio New Zealand.

"The forecast overnight didn't match the actual rainfall - we had heavy, heavy rain all night on top of what is a damaged system."

Ms Dalziel said the priority for sandbags was for businesses that had not been hit by floods before.

"We are obviously going to review the sandbagging issue, I've already raised that with the minister of Civil Defence. So obviously it is of major concern, but the scale of that ... I don't know how many sandbags would have been required to prevent the damage that occurred."

Ms Dalziel will meet with engineers this morning and ask them whether there needed to be a reassessment of the flood risk modelling.

"A one-in-100-year event has given us what actually happens, as opposed to what's predicted to happen, so it's far more accurate. We'll be asking questions about what needs to be done - how can we scale up action in this area?"

Ms Dalziel said Canterbury Earthquake Recovery Minister Gerry Brownlee would also attend the meeting.

Weather around the country is expected to improve through today, with wet and windy conditions moving away from New Zealand.

MetService meteorologist John Law said the low pressure system, which caused havoc for Cantabrians, had moved further north through yesterday and overnight, and would eventually clear by today.

All severe weather warnings and watches in place for the bottom of the North Island, Hawkes Bay and Gisborne had been lifted this morning, he said.

"The low pressure that brought the pretty unsettled weather is starting to pull away and beyond that things are looking much quieter through today and into the weekend."

As the pressure system petered out, those further north were some showers for residents further north were likely over today, however fine and settled weather should be in place by tomorrow, Mr Law said.

Quiet weather was also expected in most places around the country for the weekend, he said.

Dalziel toured the areas worst hit by the once-in-a-century storm with Earthquake Recovery Minister Gerry Brownlee yesterday. Both said they had never seen anything like it.

"Everywhere I looked I was going, 'My goodness'," Ms Dalziel said.

She realised it would be the last straw for some residents.

"Those that are in the really badly affected areas that have been affected before ... it's just kind of like the end-of-the-tether stuff."

Matthew Coleman is among those considering quitting Christchurch in the wake of the devastating storm that dumped 160mm of rain on parts of the region in 24 hours. He had to carry his year-old son through waist-high water in rain and howling wind.

"It was a nightmare basically."

Mr Coleman and his family live in Carrick St, Mairehau. He said the road floods nearly every time it rains, but the latest incident had forced him and his wife to starting thinking about moving.

"We're worried about our health and the water quality, because there was sewage coming up and we worry about it every time it rains."

Hundreds of residents are bracing themselves for a major clean-up today after the heavy rains that followed Tuesday's fierce winds finally started to ease late in the afternoon.

Residents from dozens of homes have fled their flood-stricken properties, thousands remain without power and a fuel-storage tank has been damaged by a collapsed cliff face, putting emergency services on alert.

Homeowners reported seeing sewage in the floodwaters around some of the worst-hit areas, Flockton and Mairehau.

The city council said sewage plants at Duvauchelle and Diamond Harbour were affected and warned residents floodwaters were likely to be contaminated.

People were asked to avoid rivers and beaches for at least two days.

Water was being trucked into Little River and the council asked Banks Peninsula residents to conserve water.

Welfare centres had been created but so far only a handful of people had needed them. A council spokeswoman said many people whose homes suffered flood or storm damage would be staying with friends or family.

It was not yet known how many properties suffered from storm damage, she said.

Ms Dalziel said many residents were questioning whether insurance would cover their properties.

"I've called a meeting for [today] where we're going to look at the progress that we've made ... The question I want an answer to is does this event change any assumptions that we've been operating under."

Twenty homes in Lyttelton were evacuated after a slip damaged a fuel-storage tank at the port.

The aviation fuel leaking from the tank was contained by the Fire Service, port authorities and fuel companies and there was no immediate risk to the public, the city council said.

The Fire Service was inundated with calls from residents reporting damage to their homes and flooding.

They received 187 flooding-related callouts between 6am and 4pm, southern fire communications shift manager Brent Dunn said.

"There was very heavy surface flooding - a lot of areas we couldn't even get to, just because it was so deep; the rivers were overflowing."

About 1000 Orion customers remained without power at 8pm, with the majority expected to stay disconnected overnight, the electricity company said.

It had been unable to access the electricity network to restore power and the situation could remain for the next few days.

The majority of customers without power were around Banks Peninsula, with most of the peninsula affected. Some pockets of Christchurch and surrounding areas also experienced outages.

City council workers sand bag shops in Shirley, Christchurch. Photo / Getty Images

Christchurch is experiencing more frequent and severe flooding due to the impact of the earthquakes, University of Canterbury researchers say.

Since the first major quake in September 2010, the liquefaction, subsidence and uplift were posing an enhanced flooding threat to Christchurch, said University of Canterbury geography masters student Su Young Ko.

"One of the primary contributors to increased flooding hazards in Christchurch is the earthquakes, which resulted in subsidence in some areas, narrowing of channels and uplifting of river beds."

A key case study, looking at the effects of the quakes on flooding patterns across the city, is being undertaken by Environment Canterbury, Civil and Natural Resources Engineering and Dr Christopher Gomez from the university's geography department.

Civil and natural resources engineer Dr Sonia Giovinazzi and geography researcher Dr Deirdre Hart have also been investigating the increased flooding hazard attributed to the quakes.