The $4.4 billion City Rail Link faces the prospect of major delays and extra costs from the latest plans to reboot light rail in Auckland.
The Herald understands the new Aotea station for the City Rail Link is one of two options to start light rail at the city end. The other option is Wynyard Quarter.
Transport Minister Michael Wood last Wednesday announced plans for getting light rail back on track by involving Aucklanders in a six-month process to come up with a new scheme from central Auckland to the airport.
The process involves many tough calls for Aucklanders, politicians and officials, including where to begin light rail at the city end and whether the project will be built at street level or underground to Mt Roskill.
From there, it is envisaged light rail will straddle SH20 to the airport.
City Rail Link Ltd has welcomed the suggestion from the Government that it could be put in charge of delivering light rail. The other option is a new joint venture between the Government and Auckland Council, Wood said.
CRL's chief executive Dr Sean Sweeney said it had demonstrated it can progress a challenging and complex multi-billion dollar project and believed it has the skills to deliver light rail.
Asked about the prospect of light rail starting at Aotea station, Sweeney said discussions in the public arena about light rail routes is speculation.
He said work is well advanced on the Aotea station between Victoria and Wellesley Sts below Albert St, including relocating utilities and building the first walls and foundations.
"While that construction continues there is always the ability to connect light and heavy rail above or below ground," Sweeney said.
Changing the current work programme at Aotea station for light rail would have a major impact on the project and disruption in the central city.
CRL would either have to stop work on the station and wait for light rail to be designed and consented to connect to the two different modes of rail.
The other option would be to complete the Aotea station for the rail link to open in 2024 and close it at a later date to connect to light rail.
When the Herald first heard about the possibility of light rail connecting to the Aotea station last November, Sweeney said the opportunity for major change was gone.
"When I turned up two years ago I was asked if we could just slow down and let light rail catch up.
"We let them (two bidders for the project at the time) we have done our design and consents and building what we consented, he said.
At the time, Sweeney said there was an allowance for a heavy rail connection to the North Shore in the design for the City Rail Link at Aotea station but not light rail.
The decision on the location of light rail at the city end will be made by an establishment unit comprising council, transport and housing officials tasked with coming up with the mode, route, costings and financing options for Cabinet to consider later this year.
Wood has called light rail the biggest "city-shaping" piece of infrastructure since the Auckland Harbour Bridge, which opened in 1959.
"The city centre to Māngere line will be a backbone that eventually will link with the North and North-west, forming a rapid transit network that fully integrates with other forms of transport across the city," he said.