We're doubling down on flood recovery efforts around western dams

14/05/2024
We are more than doubling the number of crews working on flood and cyclone recovery works around the Waitākere dams to deliver crucial repairs before winter sets in.

Last year’s Auckland Anniversary Floods and Cyclone Gabrielle events caused extensive damage with landslips taking out watermains, wastewater pipes and causing issues in our dam catchments.

Asset upgrades and renewals manager Suzanne Lucas says they’ve increased the number of crews working in the western dam catchments from two to five to deliver critical repair projects before winter sets in.

The crews cleared up a landslide on a crucial water main in late April
Photo: The crews cleared up a landslide on a crucial water main in late April

“Our crews and contractors have achieved a lot since the beginning of the summer, clearing up about 21 slips around critical accessways, and rebuilding many of the pipe bridges and culverts lost in last year’s anniversary floods and cyclone event.

“We’ve also built retaining walls to make these assets more resilient to future severe weather events.

“I am extremely impressed with our crews; they have put in an incredible effort to stabilise our sites and get the repairs done in the last eight months.”

The Black Hawk enabled Watercare to have heavier equipment and more materials, up to three tonnes, enabling our crews to work more efficiently
Photo: The Black Hawk transported heavier equipment and more materials, up to three tonnes, enabling our crews to work more efficiently

Lucas says the repairs our crews and contractors are carrying out are challenging due to their remoteness and difficult accessibility.

“As a result, we had to think outside the box about how we transport specialist equipment and materials in as well as be more innovative with our designs for the repairs.

“The solution for getting around this issue was to helicopter in the specialist equipment and materials like gravel, pipework, and excavators.

“However, since the helicopter could only safely transport equipment or machines up to a few hundred kilograms, we were quite limited to very small machinery we could bring in.”

Lucas says this all changed in March, thanks to the assistance of a Black Hawk helicopter that could transport equipment weighing up to three tonnes.

“Having the assistance of a Black Hawk meant we could transport heavier equipment and more materials, enabling our crews to work more efficiently.

“Having a Black Hawk for the week allowed us to bring in infrastructure in full pieces, instead of in smaller pieces across multiple helicopter trips.

“The Black Hawk will be returning in July to remove equipment before we shut down for the winter."
Lucas says work will be limited during the winter period as the risk of land instability tends to be much greater due to the increase of rainfall and high winds.

“We have strict protocols we need to follow to keep our teams safe. Given the risk of land instability, rainfall and wind thresholds mean we can’t send people in if they’re exceeded – for example, if there’s more than 50mm of rain in 48 hours, work can’t proceed.

“Besides the weather, the days are much shorter in winter, which doesn’t give us much of a window to get things done on the ground.

 “We'll still have a crew who can monitor the sites for slips and critical infrastructure, but our focus will be on finalising the designs for the remaining repairs needed in our dam catchments so we’re all ready to go when next summer comes.”