Timeline of a flood in Wairoa: Hawke’s Bay Regional Council defends decisions around river mouth opening

* Clarification: An earlier sentence in this article that sought to summarise Cr Ormsby’s Nine to Noon interview has been updated. Ormsby was not concluding that the river mouth opening could have been undertaken earlier. HBRC is reviewing the timeline of events.

Wairoa’s mayor says Hawke’s Bay Regional Council (HBRC) could have moved earlier to clear the Wairoa River mouth before a storm hit, flooding much of the lower part of town.

But HBRC staff say the opening simply would not have stayed in place if it was done earlier.

Thousands were left powerless, and hundreds were evacuated from homes on Wednesday as swells, tides and rivers rose in unison in Hawke’s Bay.

As of Wednesday night, more than 400 properties in the Wairoa District had been affected by flooding, including more than 100 “significantly impacted” homes.

The flooding to the southern parts of Wairoa town was unlike anything Kopu Rd resident of 30 years Paul Toothill had seen before.

HBRC put contractors on standby last Friday for the Wairoa River bar, a raised area of sediment that builds up in the mouth of the Wairoa River, but they did not begin work until Tuesday.

Wairoa mayor Craig Little believes work to clear the bar should have started earlier and said community members warned the HBRC days earlier.

Wairoa Mayor Craig Little says his council intends to find out what happened with the Wairoa River bar shortly before and during floods this week. Photo / Paul Taylor

The Hawke’s Bay Regional Council response

Chris Dolley, HBRC group manager of asset management, said Wairoa contracting team Pryde Contracting was on standby on Friday, June 21.

“At the time, the forecast rain didn’t justify starting the work as there would likely be insufficient flow in the river to keep a new opening in place,” Dolley said.

Council chairperson Hinewai Ormsby told RNZ’s Nine to Noon on Thursday decisions about opening the Wairoa bar were made on the best information available at the time.

She said there was agreement that if the mouth had been opened sooner “we wouldn’t have seen the devastation that we have in Wairoa”.

Hamish Pryde, of Pryde Contracting, has worked on the bar for decades.

He told RNZ there may have been a risk assessment failure, and the decision to start work came too late.

MetService issued orange rain warnings for northern parts of Hawke’s Bay around Wairoa about 10am Monday.

With the revised forecast, Dolley said the HBRC identified Wednesday as the best opportunity to successfully open the river mouth.

“Pryde mobilised equipment to the site on Monday afternoon and began work on Tuesday.”

Little sent a text to Ormsby and CEO Nic Peet on Monday at 4.13pm.

It said: “Hey I’m getting calls from concerned residents re the state of the Wairoa River bar and the imminent weather event. Could you please give me some clarification around the status and whether the community should have concerns[?]. Kind Regards Craig”.

Pryde Contracting discovered on Tuesday morning they had lost two diggers and a bulldozer parked overnight, after they tried to open the Wairoa River bar.

HBRC said at 8.45am on Wednesday, the river mouth opening was suspended after a safety assessment.

“The machinery is flooded, and so is the access track between where the machinery is located and the bar.”

Ormsby said the process to open the bar was complex.

“You need to open one and shut the other because there are two pathways to the river. We have had contractors who have had to stop being inundated and unsafe.”

Wairoa Mayor Craig Little says they are in crisis. Photo / Paul Taylor

‘We have flooded where we have never flooded before.’

When asked what he thought of the HBRC stance that it wasn’t the right time to open the bar earlier, Little said: “The community is saying different”.

The council would find out what had happened with the bar, he said.

“We have flooded where we have never flooded before.”

Little was critical of HBRC’s claim that contractors were on standby.

“I am not a bar expert, but I don’t think they were on standby. To me, that means having equipment on-site, but they didn’t.”

Dolley said every bar opening was different and took a different amount of time.

“Opening the river mouth is a significant job as it involves removing large volumes of soft gravel, and working with the conditions at the time.”

The Wairoa River bar caused significant issues during Cyclone Gabrielle.

Wairoa’s Flood Protection Stakeholder Group chair Lawrence Yule said in April there was a need to capture local knowledge around the bar and preserve that for future generations, to support robust processes.

A report released in April about last year’s flooding said there would be “improvements” to the bar and it would be “proactively managed” with local input and short-term decision-making ability.

James Pocock joined Hawke’s Bay Today in 2021 and writes breaking news and features, with a focus on the environment, local government and post-cyclone issues in the region. He has a keen interest in finding the bigger picture in research and making it more accessible to audiences. He lives in Napier. james.pocock@nzme.co.nz

Gary Hamilton-Irvine is a Hawke’s Bay-based reporter who covers a range of news topics including business, councils, breaking news and cyclone recovery. He formerly worked at News Corp Australia.