25 May 2023

'Hard lessons we need to learn' - Stormwater conference faces harsh climate reality

8:32 pm on 25 May 2023
Flooding on Porana Road, Wairau Valley on 9 May, 2023.

Flooding on Porana Road, Wairau Valley on 9 May, 2023. Photo: RNZ / Luka Forman

A dour mood hung above this year's Stormwater New Zealand Conference, as attendees reflected on months of flooding and severe weather.

"I need to apologise in advance for any recent trauma that this presentation might trigger," Auckland Council's Nick Brown said before playing a montage of the flood's most destructive moments.

The Regional Planning Manager reflected on gaps in communication that had some unwitting Aucklanders swimming through contaminated water.

"This young person here," he pointed out in one image, was "soaking wet not from the rainfall but because she and her mates decided swimming in raw sewage would be delightful".

Throughout the seven-day downpour, many Aucklanders did not understand the risks, he said.

"People didn't know, for example, that the Wairau pump station was broken and that the raw sewage of 70,000 people was discharging into the area."

Hawke's Bay Regional Council's Asset Management Group Manager, Chris Dolley, was similarly reflective in his speech.

"There's some hard lessons we need to learn.

"Often when our technical specialists are providing advice... that advice isn't always followed. In fact, some of our statutory mechanisms allow it to be readily challenged.

"That's something I think we need to work through."

Other speakers were more concerned by the future.

Cars drive through surface flooding in central Auckland as rain pelts the region on 9 May 2023.

Cars drive through surface flooding in central Auckland as rain pelts the region. Photo: RNZ / Isra'a Emhail

"In the near future we are going to have very extreme events happening," NIWA Principal Scientist Graeme Smart said.

"More frequent rain means more intense rain. In periods where we get more two-year floods, we get more 50-year floods."

Higher global temperatures meant small but steady increases in ocean evaporation.

"What goes up must come down."

Smart noted dozens of severe weather events around the world in just the past month: "3rd of May in Italy, nearly 200 millimetres in 24 hours. 7th of May in Pakistan, flooding and landslides, 13th of May, tornado in Texas, 14th of May, Cyclone Mocha hit Bangladesh and Myanmar..."

He also listed other weather events in the UK, Rwanda, Uganda, Democratic Republic of Congo, Sierra Leone, Somalia and Ethiopia.

Philip Barber and Sarah Johnson say they won't be returning to live in the Esk Valley.

Philip Barber and Sarah Johnson had to shelter on the roof with their two children aged three and five on the night of the flood. Photo: RNZ / Robin Martin

The rules had changed, Smart said. The old metrics for what constituted a "once in a century" weather event were severely outdated.

"Because flood sizes have increased, what was a hundred-year event has become a 60-year event.

"We've got inadequate infrastructure and instrumentation. Most of our urban drainage and flood protection schemes are under-designed."

Auckland's Anniversary Weekend floods, Cyclone Gabrielle, and a host of other storms had created an immediate demand for defensive measures and flood insurance.

Climate change researcher Belinda Storey warned against jumping on short-term solutions.

"Insurance transfers risk, defences and remediations suppress risk.

"You'll hear people say that they reduce risk, but they don't. The only way to permanently reduce risk is to get out of harm's way."

So long as houses remained in flood-prone areas, they would keep flooding.

"If you are building a house today, if it gets damaged and you rebuild it, you're very likely to have to rebuild it [again] fairly soon.

"I hope we don't end up in a situation in New Zealand where we are rebuilding houses 30 or 40 times in the next 50 years. I hope that we learn."

Storm Environmental's Peter Christensen also worried quick fixes would be chosen over long-term solutions.

"It's tempting to allow corners to be cut, to follow the path of least resistance.

"After all: It won't flood there for a hundred years, right? But we need to stop allowing that short-term thinking to influence decisions around communities that will be located in the area for decades if not centuries."

Convincing financiers to invest in large-scale infrastructure projects meant getting them to care about complex graphs and hypothetical numbers.

"Communication is the key," Smart said.

"What we have to remember is that almost everyone here has a high level of technical education. We understand probabilities and uncertainties. A huge proportion of our population works much more with emotion.

"We have to communicate at an emotional level, as well as at a scientific level."

Flooding on Candia Road in Swanson, Waitakere City on 9 May 2023.

Flooding has affected many houses this year. Photo: RNZ / Amy Williams

Call for aid for accommodation costs

One group is calling for the government to pay accommodation costs for people displaced from flood-damaged homes as their insurance payments run dry and they remain in limbo.

The advocacy group West Auckland Is Flooding (WAIF) wants a fund people can apply for to cover the cost of their temporary accommodation as they wait for authorities to decide about managed retreat.

WAIF spokesperson Morgan Allen told Checkpoint it was time for the government to step in.

"The future is pretty grim at the moment unless there's some real decisive action quite quickly from the government and I guess in partnership with the council."

Allen said people had a very limited amount of funds coming from their insurer for accommodations and the long time since the flooding and cyclone was making it difficult.

"Normally if somebody's house burned down or there was some event, you know, a tornado hit your house, you wouldn't wait four months before you would start rebuilding.

"You would look to settle your claim quickly as possible, take your money from your insurer and get on with it."

Temporary accommodation costs vary and many arrangements were made in haste after flooding, "so there's some situations where people would have to stretch themselves further than they would want to".

"Some families have had to split into different parts, we've got kids not living in the same homes as their parents, people may be overstaying their welcome in some situations."

The reason that people have not been able to carry on is because there has been a lack of clarity from government on whether some homes will even be rebuilt, Allen said.

People cannot survive for months in some instances paying both mortgages and accommodation costs and possibly having to default on mortgages or going bankrupt, he said.

Allen said the group has had some dialogue with the government, but would like to see stronger action.

"This is why we are putting the call out … this is a real looming social disaster we are seeing coming."

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