Auckland floods: Council had to abort flood plain improvements 10 years ago

Monday, 6 September 2021

A number of properties in Auckland's Kumeū are under water after a storm. This video has no sound.

Flood-calming developments were canned in Kumeū 10 years ago because landowners wouldn’t allow access to their properties, Auckland Council says.

It comes after the northwest Auckland township was hit by a major storm on August 31, flooding homes and businesses.

More than 150 millimeters of water covered the district, and the nearby Upper Huia Dam went from 45 percent capacity to overflowing in the span of only four hours.

A man paddles down flooded Shamrock Drive during the Kumeū floods on August 31.

Auckland Council said the previous Rodney District Council had started a flood mitigation project that involved digging out flood plains beside Kumeū River, so flood water could flow through a deeper cross-section.

* Auckland rural tank users already running dry after winter

* Sky harvest – turning the tide on rainwater tanks

Flood waters cover a fleet of utes in Kumeū.

There were three stages to the project. The first was carried out by Rodney District Council, on reserve land that council owned. That land was then sold back to the public.

Auckland Council says the flood damage was too great for any flood-mitigation to prevent.

The second stage was carried out by a land developer as a condition of resource consent.

However, the council said, the third stage that would have seen mitigation take place between the residential development and Oraha Rd could not be completed.

“Key landowners did not consent to an easement across their land to enable the works to be undertaken,” head of Healthy Waters strategy Andrew Chin said.

Craig Walker, who runs a building removals company, has been assisting with the flood recovery.

Walker, who has lived in Kumeū for decades, said he was disappointed the flood-calming measures were not completed.

“There's been work done in part, but not as a whole. The authorities seem to have half-iced the cake, not the whole cake,” he said.

Healthy Waters maintains catch-pits (commonly referred to as mud tanks) as part of the stormwater network.

There are tens of thousands across the region, often cleaned on a rolling one- to two-year cycle.

“The catchpits within public roads in the Kumeū area were last cleared in mid-February 2021,” said Chin.

“With the severity of this storm and the sheer amount of water, no additional amount of clearing would have helped.

“The piped stormwater system is not designed to cope with the type of extreme weather we experienced [on August 31], and we will always experience overflows in an extreme weather situation.”