Petone subway upgrade, over budget and overdue
If the government needs a case study of why infrastructure projects take longer than expected and costs sky-rocket, it could check out the Petone Railway Station.
In September, the Lower Hutt station’s subway was closed for an upgrade. It was supposed to cost $1.35 million and be finished by March this year. It is now scheduled to be finished in July with the cost rising by $400,000.
When the subway is finished, it will link in to the 3.5km Melling to Petone cycleway, which was opened last October.
When work began on the cycleway in 2019, it was supposed to cost $30m. Two years earlier the figure had been $17m. Geo-technical issues, soil contamination and the need to move underground services all added to the complexity of the project, and the final cost was $65m.
Metlink group manager Samantha Gain said the subway upgrade aimed to improve public safety and build long-term resilience.
Once construction began, however, a number of problems emerged.
“We discovered that improvements were needed to the concrete structures which make up the station’s subway and ramps, which has meant that additional work is required.”
The existing pumps and sump, needed to remove water from the subway, also needed upgrading.
Greater Wellington transport chair Thomas Nash said the delay and extra cost were frustrating but pointed to a bigger problem facing the country.
Geo-technical issues were a common problem in Wellington and he said that better planning was needed to identify what was underground before projects began.
Although there was often scepticism over how much planning was required, Nash said that it could be the key to projects being completed within budget and on time.
With the government looking to create a “pipeline” of major infrastructure projects, it had to address the issue of retaining skilled staff and better geo-technical planning, he said. Contractors needed to understand ground conditions before construction started, rather than finding out once work begins.
Infrastructure New Zealand chief executive Nick Leggett said the problem of projects increasing in cost and taking longer was a world-wide issue.
He agreed with Nash that better planning was the key, especially with the country’s geo-technical issues.
Cost overrun and delays created a number of negative impacts.