A small, flood-prone Northland community has withstood a 10-year rainfall event, thanks to new flood protection works led by Northland Regional Council.
Around 300ml of rain fell on the Far North’s Matangirau catchment during Ex-Tropical Cyclone Tam, the most rain recorded in the area in a decade and almost twice the rainfall recorded across Northland.
Flood protection measures were installed last year at Matangirau as part of the $5.735 million Flood-Resilient Māori Communities and Marae project.
The project (funded by the Local Government Flood Resilience Co-Investment Fund and NRC) aims to reduce flood risks for six flood-affected Māori communities (Kawakawa, Otiria-Moerewa, Kaeo, Matangirau, Whirinaki and Punuruku) and 35 marae across Te Tai Tokerau.
Local Robert Rush said prior to the flood works, his whare was always the first to flood when there was heavy rainfall.
Their local marae would also always go under water.
Yet after the flood mitigation works undertaken by NRC, Rush said, the results had been fantastic.
“It’s been a work in progress, especially showing our whānau that the council were only there to help and not to steal our land,” Rush said.
“We’ve had stop banks and river works done around our homestead and it hasn’t flooded since.
“We also had some work done just a couple of weeks before ex-Cyclone Tam, which was perfect timing because we didn’t flood during that time either, nor did my grandfather’s house which is near the new marae.”
NRC Te Ruarangi (Māori and council working party) Whangaroa hapū representative and Matangirau haukainga Nyze Manuel agreed the benefits of the flood works were obvious.
She said the mahi of Te Ruarangi had also played a critical role in the activation and front line of Māori communities during these times.
“Well we’re not under water, so that’s awesome!” Manuel said.
“Through our Te Ruarangi network we were able to get out communications to people about the weather in a fast and efficient way.
“And as more flood works are done by NRC, we’ll see less flood water in these vulnerable areas.”
Matangirau’s flood mitigation is based on an engineering method called ‘floodway benching’ designed to reduce flood risk for homes and the marae upstream of the Wainui Road Bridge.
A 1960s rebuild of the bridge (which raised the bridge and approaches by about two metres above the existing flood plain) unintentionally worsened flooding by creating a ‘detention dam’ effect during heavy rainfall, capturing and holding excess water during heavy rainfall events.
As a child, Rush said he didn’t recall any flooding until the local road and bridge works were completed.
“We’ve had a whole lot of issues and have moaned about that for years, that’s why we built our whare where it is now because it never used to flood there,” he said.
“That’s why it was essential to get the flood works done as we’ve been flooded 3-4 times now and are no longer able to insure our house.”
The new benching works aim to reverse this damage by giving floodwaters more space to spread out, allowing more water to flow under the bridge.
This proven approach, used successfully in Awanui, maintains the river channel while adding a higher, wider ‘bench’ for safer floodwater flow.
Northland Regional Council Rivers Manager Joe Camuso said the recent weather event had proven the value of investing early in communities like Matangirau.
While it wasn’t a ‘miracle’ cure for flooding, Camuso said it had made a significant improvement on the impact of heavy rainfall to the area.
“What we’re seeing now is the flow regime is much more efficient, so we’re seeing more water flowing under the bridge, which means less flooding during large rainfall events,” Camuso said.
“While this is great, it is only built to withstand up to a 50-year flood event, of which there is only a two per cent likelihood each year.”
Flooding remains one of Northland’s most damaging and frequent natural hazards, impacting social, economic, and cultural wellbeing.
For Māori communities, the risk is particularly acute, with marae often located in low-lying, flood-prone areas.
During past storm events like Cyclone Gabrielle, widespread damage was seen across Māori communities, particularly to papakāinga (communal housing) and low-income areas.
Ensuring marae were more resilient, Camuso said, would mean more communities would be better off moving forward.
“In a flood event, marae become like a defacto civil defence hub, which often need to house and protect local whānau impacted by floodwaters,” he said.
“In the past week we’ve received so many emails from marae we’ve worked with, thanking us and telling us of the benefit they’re already seeing from the flood protection works.
“I’d like to thank the local whānau and hapū who have worked with us to ensure these flood works are a success.”
Rush said he too was grateful for the support from NRC to help flood-proof their whenua.
“Joe and his team have been a big part of this from early on and have been awesome over the years, which has really benefitted our whānau in the area.”
The flood resilience initiative not only focuses on physical protection like benching and stop banks but includes emergency planning, community-led adaptation, and exploring options for relocating the most vulnerable marae.
Site works across the region began in December 2023, with practical completion expected by mid 2025.
A video taken outside the Rush whānau homestead during the peak of the rainfall during ex-Cyclone Tam