The ‘hairpin’ of Pākōwhai: Should a crucial piece of Hawke’s Bay flood infrastructure be changed, or should residents have to leave?

The point at which the Tūtaekurī and Ngāruroro river stopbanks meet in Pākōwhai was designed 60 years ago to prevent catastrophic flooding on Hawke’s Bay’s flood plains. But during Cyclone Gabrielle it turned into a proxy dam that turned the community into a 250-hectare lake. The question now is whether homeowners should have to leave, or if the confluence’s flaws should be fixed. James Pocock reports.

Duncan McPhail points out the “hairpin” that helped drowned his home of 40 years.

He’s walking along the top of the right Tūtaekurī River stopbank at the bottom of the Heretaunga Plains, surveying the now-repaired breach where it joins with the left stopbank of Ngāruroro River.

On February 14, the “hairpin” that was supposed to protect McPhail and Pākōwhai residents overtopped. It was a nightmare scenario, with the water then pooling around it like a dam until homes were submerged.

“This was fit for purpose in the 60s, when they brought the Ngāruroro River across and joined it into the same channel as the Tūtaekurī,” McPhail says.

“It served well for 60 years, but I don’t believe it is fit for purpose now.”

McPhail and his wife were blindsided when they learnt last week that their home on Brookfields Rd fell just inside the provisional Category 3 zone for Pākōwhai.

The area of Pākōwhai immediately beside the hairpin meeting point of the two rivers is now provisionally classified as Category 3. Photo / Supplied

Category 3 is the highest risk category and refers to areas deemed unsafe to live in due to unacceptable flood risks.

Despite what happened in February - his home was under 4.5 metres of water - McPhail feels it’s still reasonable to live near the hairpin.

His reasoning is that this crucial piece of river infrastructure - the meeting point of two major Hawke’s Bay rivers - simply has to be changed in some way anyway, therefore a Category 2 reclassification, with an expectation of work to future proof for flood events, is what he had expected.

McPhail points to the Tūtaekuri River floodplain, where a layer of silt piled up from previous flooding has made it visibly shallower than the side of the stopbank facing Pākōwhai.

His suggestion is for the Hawke’s Bay Regional Council to routinely dig out that layer to increase the channel’s capacity for water in a flood and restore the protection that the stopbank is supposed to provide.

He also suggests central government purchases land on either side of the rivers from the point where they converge to the ocean to the tip of the “hairpin”, so the current stopbanks can be widened out and the capacity of both rivers to flow out into the ocean during floods can be increased.

The lake that built up around homes in Pākōwhai on February 14. Photo / Dee Southall

It’s an idea similar to the “Making Room for Rivers” concept advocated for by Forest and Bird.

Finally, McPhail wants the hairpin to have an exit point - he wants a channel between the two rivers where they meet to be dug out right down to the sea to increase outflow capacity, so the stopbanks are less likely to turn into a dam again.

He said he and other residents were informed by a council spokesperson at a community meeting this week that one of the criteria that determined the category three area was height above sea level - three metres and below in this case.

“It’s not some arbitrary height above sea level that determines Pākōwhai’s flood risk, it is its depth below the stopbanks that surround it,” he said.

Duncan McPhail, resident of the provisional Pākōwhai "red zone", walks on the existing stopbank on the Tūtaekurī River. Photo / Warren Buckland

He said climate change meant it would be likely that there will be more inundation and higher floods in the future and buying out “red-zoned” property would no longer be an affordable option for the Government.

“It is no doubt cheaper to ignore now and put a handful of us in Category 3, households and properties that they will have to remunerate to not live here again, but I say what about the likely higher and longer inundation in the future?

“Would it still be cheaper than going to four metres above sea level, or less with the sea level rising, which would put the entire Pākōwhai straight in line for having to be zoned out of residential existence?

“We need vision, leadership and courage. Not a cheap cop-out short-term answer.”

The McPhail's home was hit by about 4.5 metres of floodwater on February 14. Duncan McPhail says future disasters will be worse if nothing is changed. Photo / Warren Buckland

Until further community engagement is had around provisional zoning, it will remain unclear whether McPhail’s suggestions are viable in the eyes of the council.

A Hawke’s Bay Regional Council spokeswoman said the council was not in a position to discuss specific solutions while land categorisation considerations and the community and individual-affected property meetings have yet to take place later this month.

“We would encourage all affected landowners to attend the first round of community meetings happening later in June to learn about land categorisation and the next steps councils will be taking with property owners in affected communities,” the spokeswoman said.

“At the second round of meetings, council staff will be eager to share what they know and learn from locals what they know about rivers and living near them.”