Auckland Council wants to fast-track flood prevention work that would save 51 Māngere homes

Auckland Council wants to fast-track plans that would prevent 51 homes being demolished in Māngere due to flood risk.

The south Auckland suburb was one of the region's worst-hit areas in the 2023 storms. Close to 200 homes flooded near Te Ararata Stream the night of the catastrophic Auckland Anniversary weekend deluge, including many state homes.

Since then, Kāinga Ora has demolished 21 flood-damaged homes in Māngere with another 23 in the suburb earmarked for the bulldozers - half the 89 total state homes to be levelled in Auckland.

Auckland Council said up to 900 privately owned homes would need to be demolished or removed across the region over the next two years.

Residents living near the creek told RNZ they still feared flooding because the water still rose from the stream onto nearby roads during heavy rain.

The council said it wanted its plan to reduce the flood risk for 244 homes in the area progressed under urgency - fast-tracking the consenting process to seven months, instead of it taking a year or more.

Of the 244 homes in Māngere that would be better protected, the council said 51 could be saved from demolition.

Transport and infrastructure committee chair John Watson said that was why councillors had chosen to fast-track the consenting process.

"We are seeing more extreme weather, and many parts of Auckland are becoming increasingly vulnerable to heavy rain. If these works go ahead, we'll see hundreds of homes in Māngere with a reduced flood risk," he said.

"Some of these homes are classed as having an intolerable risk to life and would otherwise have had to be removed, so it's important to do what we can to deliver these projects quickly."

Councillors have requested an Order in Council from central government to fast-track the Māngere projects. That was subject to ministerial and Cabinet approval.

The proposal included increasing Te Ararata Stream's capacity, installing debris catchers, while increasing capacity of the nearby Harania catchment.

It was the first of two flood resilience plans tabled as part of the council's Making Space for Water programme, awaiting sign-off for government co-funding.

The other was a $5m project in Muriwai where 60 properties would benefit from reduced flood risk and four from reduced landslide risk.

It was expected the Māngere project would cost around $53 million.

Manukau ward councillor Lotu Fuli said Māngere was a priority because it was among the areas with the highest flood risk.

"Many areas were impacted and many also need these projects so that the local community can benefit. We look forward to working collaboratively with our community, local board and iwi groups to deliver these projects that will help bolster flood resilience in the wider Māngere area," she said.

"We know that the works in Māngere can be done so it makes sense to start here - but this is only the beginning of a much wider, regional programme."

Auckland mayor Wayne Brown said the Making Space for Water programme had a series of flood resilience works planned.

"Māngere and Muriwai were among the hardest hit during Cyclone Gabrielle and the Anniversary weekend flood, and it's good to see these works are progressing quickly, so that the people living in these areas, like many in Kāinga Ora homes, are not exposed to the same risk in the future."

He said an Order in Council would help to accelerate the project and remove the immediate consenting burden and cost.

"Flood resilience projects in Māngere will protect hundreds of households from future flooding risk and I look forward to working closely with Kāinga Ora in developing new homes in these places in the future."

Auckland Council had submitted its business cases for the Māngere and Muriwai projects to government for approval and co-funding and was awaiting a decision.

The business cases for the projects were not yet publicly available.

Proposed Te Ararata catchment works include;

• Increasing the stream capacity under Walmsley Road bridge
• Improving the maintenance access for the Mahunga Drive culverts
• Installing debris capture devices along Te Ararata stream.

Proposed Harania catchment works include:

• Replacing embankments at Tennessee Avenue and Blake Road with an open stream and pipe bridges to increase water capacity
• Enhancing the newly created stream area with landscaping and planting.

Proposed Muriwai works include:

• Installing a reinforced stop-bank on Domain Crescent
• Upgrading open channel roadside drains and driveway crossings along Motutara Road to increase the stormwater capacity
• Installing sediment and debris traps that reduce the frequency of blockages and make maintenance of the network easier.