Work under way to stabilise high-risk Wellington slope

Thursday, 3 April 2025

Work to stabilise a large section of “high risk” hillside on a main suburban arterial road is being both lauded — by affected residents — and criticised, by inconvenienced commuters.

An anchored shotcrete wall and erosion control mesh is being installed along a broad stretch of Birdwood St, one of the main routes into and out of Karori and the scene of numerous land slides.

The estimated total cost of the project is $2.1 million, excluding GST, according to Wellington City Council.

In 2015 two cars were damaged by debris from a five-metre-wide slip and in 2018 another chunk of hillside collapsed following intense rain in the wake of ex-Cyclone Gita.

In August 2022 — the year the council recorded a record 1143 slips over winter — another slip blocked the road entirely, closing it for almost two weeks. At the same time Chaytor Street — the other arterial route through to Karori — was down to a single lane after a rocky section of hillside below Birdwood St tumbled onto the road.

Remedial work on the slope, identified by engineers as a high risk to traffic and pedestrians, is expected to take six months. The recently installed cycle land and northbound vehicle lane will be closed, and southbound, downhill traffic, subject to stop-go measures. Most traffic is being detoured through Chaytor St.

Birdwood St is on the number 21, 37, 739 and 614 bus routes and has an average daily traffic count of 4682. The potential disruption has some commuters up in arms, with calls for the council to look into a one-way system that opened up a lane downhill to the city centre in the morning and uphill in the evening.

“It’s only been one day and the traffic has already killed me,” said one local, a cyclist and bus user.

Meanwhile, residents with homes perched on the hill above the slope are grateful that the work is finally getting done, despite it likely being a prolonged and noisy process. “I feel a lot better now that the work is under way,” a homeowner told The Post.

Movement sensors had been installed on the site to allow engineers to remotely monitor it until construction work began. Downer has been contracted to complete the work, with additional time allocated in the schedule to compensate for it being done over winter.

Ward councillor Diane Calvert said she was aware of the concerns around the congestion the work was causing and had a request into council officers to see if there was anything that could be done to alleviate it.