Works to replace watermains in the New Zealand Waitākere Ranges is progressing well, following damages from the Anniversary Weekend flood event in early 2023.
The watermain, which normally carries water from the Upper Nihotupu Dam to Watercare’s Huia Water Treatment Plant, has been out of service since it was damaged by landslips which occurred during the flooding event.
Environmental assets manager James Talbot said that work has been progressing at multiple sites simultaneously.
“There’s a huge amount of work going on to get the dam back in service as soon as possible,” he said.
“Our team has replaced about seven sections of pipe that had been destroyed by a landslip.”
There are however, many challenges which is proving to be difficult for the team.
“Access is a real issue for us along the Upper Nihotupu raw watermain – some equipment including a small excavator needed to be flown in to site using a helicopter,” Talbot said.
“Our contractors who are working in this challenging environment have been coping well and are getting good results.
Tallbot said when accessing sites along the Upper Nihotupu raw watermain, the company has strict protocols it follows to keep their teams safe.
Given the risk of land instability, there are rainfall and wind thresholds that mean people can’t be sent in if they’re exceeded – for example if there’s more than 50mm of rain in 48 hours work cannot proceed.
“With the weather we’ve had this year, our crews haven’t had as much time on site as they’d have liked, but overall the work is going well, and it’s looking like we’ll have the dam back in service this winter,” he said.
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