Historic rainfall hits New Zealand, causing severe flooding

Hundreds of residents in north Canterbury in New Zealand have been evacuated amid severe flooding fuelled by a one-in-100-year heavy rain over the weekend. According to NIWA, the rainfall was 200 to 400 percent of normal for the month of May, causing rivers to rise and flood. A state of emergency has been declared on Sunday, May 30, 2021, as flooding threatened thousands of homes.

The New Zealand MetService has issued a rare Red Warning for Heavy Rain for the Canterbury region prior to the deluge. 

"This is only the second red warning issued by MetService [for the Canterbury region] and this will be a significant weather event," the service said in a statement.

Heavy rains began soaking the region on Saturday, May 29, causing rivers to rapidly rise, damaging roads and bridges, and flooding many properties.

About 300 people have been forced to evacuate in Waimakariri and Timaru, while thousands of others in Ashburton were advised to prepare in case they need to flee.

Taking flight adds a whole new perspective on Canterbury’s floods @1NewsNZ pic.twitter.com/R74cvRNowx

— Ryan Boswell (@boswellryan) May 31, 2021

New Zealand declared a state of emergency in the province of Canterbury on Sunday as heavy rain flooded the region and put the homes of thousands at risk. A man was even airlifted out of dangerous floodwaters by a helicopter. pic.twitter.com/zjHtZxuuWB

— CBS News (@CBSNews) May 31, 2021

48-hour Canterbury rain figures 

The wettest locations are approaching 400 mm!

Akaroa on Banks Peninsula had more rain in the last 2 days than it had the entire year to 28 May pic.twitter.com/9MwcyK11rB

— NIWA Weather (@NiwaWeather) May 30, 2021

2 to 3 months worth of rain in 2 to 3 days

Here's a look at how Canterbury rainfall compares to the May monthly normal — 200 to 400% of normal!

Lismore, near Ashburton, received 238 mm in the last 2.2 days, the same amount it had received in the previous 187 days. pic.twitter.com/4aKhqoTDvv

— NIWA Weather (@NiwaWeather) May 31, 2021

Timaru District Council Civil Defence issued an emergency alert to people living in the Coopers Creek catchment, urging residents to evacuate. In the low-lying areas of Pines Beach, authorities also told residents to evacuate as a stuck floodgate raised the risk of further inundations.

According to NIWA, many districts in the region faced two to three months' worth of rain in just two to three days. Meanwhile, Lismore saw 238 mm (9.4 inches) in the past two days, which was the same amount it had received in the last 187 days.

Akaroa registered 188 mm (7 inches) in the previous two days, which was more than the total rainfall for the entire year so far.

The New Zealand Herald called the event a one-in-100-year deluge. Authorities have declared a state of emergency and around 75 schools have been closed on Monday.

The Ashburton River rising from 8 cumecs to near 1400 cumecs in just over 24 hours ! pic.twitter.com/k5CVualbJP

— Dean Robertson (@Deanoss) May 30, 2021

#UPDATE Only way out of Ashburton is by air as flooding ravages regionhttps://t.co/2w1Y4eQCQs pic.twitter.com/eHrcVAI9uF

— Newstalk ZB (@NewstalkZB) May 31, 2021

Ashburton river north branch at 1pm Monday #usuallydry #ashburton pic.twitter.com/Jr3uRdYKVO

— Dean Robertson (@Deanoss) May 31, 2021

Ashburton Mayor Neil Brown said some locals had already evacuated overnight as rivers continued to rise. Half of the town, which has a population of about 35 000, could be forced to evacuate if the river's banks break, he added.

Rex Bennett, an Ashburton resident for 40 years, said he had never witnessed rain like this before. "This would be the most rain I've ever seen here."

"When we knew there was going to be heavy rain we didn't expect in the first 12 hours to get what we got, because we thought it would be daylight," said farmer Bryan Beeston, whose farm was among the worst-hit areas.

"It's just been chaos. There's nothing we can do until, like now – it's stopped raining, thank God it's stopped raining. So now we just have to let the weather run its course and that could be the next 12 hours or 24 hours"

 Pictures from RNZ reporters on the field:
1 – Either side of Ashburton River (where the footbridge is now closed)
2 – Methven highway from Ashburton to Mt Somers
3 – Selwyn River
4 – Army trucks ready to evacuate Ashburton residents if needed pic.twitter.com/h4TaMHAxHq

— RNZ (@radionz) May 30, 2021

At 10am today the Ashburton River was at 1252 cubic metres dropping from its peak level yesterday of 1448 cubic metres – before the rain started it was under 6 cubic metres.

Photos by RNZ's Nathan McKinnon.

Live updates here: https://t.co/LMUOzYYZgZ pic.twitter.com/fB5oCJYMTS

— RNZ (@radionz) May 31, 2021

ASHBURTON FLOODS: the Methven highway from Ashburton to Mt Somer for @rnz_news @radionz pic.twitter.com/O0Q0puQRpZ

— Ella Stewart (@ellapetastewart) May 30, 2021

As of Monday, May 31, the Red Warning has been lifted but an Orange Rain Warning remains in place for the far north of Canterbury and southern Marlborough.

According to severe weather forecaster, William Nepe, the rain no longer met the criteria for a red warning as it was no longer widespread, but rivers in the region will remain swollen for some time and floodwaters will take time to subside.

Featured image credit: NZ Herald/YouTube