Moves to renege on support for the Basin Flyover could see cash pulled from other capital transport projects, the New Zealand Transport Agency has told the Wellington City Council.
In a letter to the council, NZTA chief executive Geoff Dangerfield warned that a last-ditch move to withdraw support for the flyover could mean other projects, including work on the Public Transport Spine Study, could be scrapped.
"Council needs to be aware that its withdrawal of its support for the bridge proposal at this late stage may have significant implications for investment in Wellington's wider transport network and ultimately on the growth and prosperity of the city," the letter obtained by The Dominion Post said.
That could mean Wellington Mayor Celia Wade-Brown's light rail plans were shelved.
But Wellington city councillors last night ignored the warning at an extraordinary meeting called by Justin Lester, instead voting eight to seven to spend $50,000 investigating other options.
That meeting was called after Auckland architect Richard Reid drafted an alternative plan to reduce congestion around the cricket ground, arguing that a second tunnel combined with the Buckle St trenching and slight alterations to the road would reduce congestion by as much as the Transport Agency claimed the $90 million flyover would.
He has not revealed exact details of the plan, but councillors agreed to the unscheduled council meeting to reconsider its position on the flyover, which it had previously supported.
Councillors were asked to vote on recommendations that they meet NZTA to discuss investigating further proposals, "not proceed ... without Wellington City Council support for the flyover", and spend $50,000 to "further explore alternative transport solutions around the Basin Reserve".
NZTA is due to lodge consent applications for the project early next year.
That prompted Mr Dangerfield to write to council chief executive Garry Poole yesterday stating that the agency needed the council to be "consistent and clear in its decision making and commitments".
The agency had worked with stakeholders and was "confident" the flyover was necessary, and there was no need to reopen the debate.
"We will also need to reconsider our support for a range of other transport network projects within Wellington City that rely on the efficiency gains to be delivered by the bridge.
"Importantly, this will include reconsideration of our support and participation in the Public Transport Spine Study and any outcomes of that work, as we will need to question how the significant step change in public transport along the core spine will be achieved without grade separation," he wrote.
The letter also said NZTA deputy chairwoman Patsy Reddy would be ringing Ms Wade-Brown to express the board's concerns.
Greater Wellington regional council chairwoman Fran Wilde said she was surprised the council would place the Basin Reserve upgrade and other transport projects in jeopardy.
The city council had previously agreed separation of east and west- bound traffic was essential.
"The options are either a tunnel or a bridge, and tunnelling is not affordable."
Yesterday's letter comes after Wellington City Council, Greater Wellington regional council and the Transport Agency announced last week the scope of the spine study was being extended to include Kilbirnie and Newtown. It originally focused on the railway station to Wellington Hospital route.
Light rail, which formed the foundation of Ms Wade-Brown's election platform, is one of three modes still being considered, after the options had been narrowed from about 80.
Last night's meeting was scheduled to start at 4pm, but was delayed after a procedural motion from Ray Ahipene-Mercer until after the regular meeting at which Mr Poole's reappointment was being debated.
It finally restarted about 10pm and councillors debated the matter for more than an hour.
Among the recommendations passed was one acknowledging the letter from NZTA, with Iona Pannett saying it "could be considered threatening", and she would raise that matter with the transport minister.
Those who supported further investigations said they believed there was further work to be done to find a better solution to traffic congestion, because the flyover would be an eyesore.
Other options, such as the Reid plan deserved further investigation, Ms Wade-Brown said. "Make sure we do that before we decide whether to support or not support the flyover."
But other councillors slammed the move as "procrastination" to try to force the matter to drop away. "What I see before me is a proposition to actually delay, delay, delay," Ngaire Best said.
Ian McKinnon said the NZTA's letter was simply the agency stating its position.
"It's been criticised for holding a pistol to our head but we'd be equally critical of NZTA if they didn't tell us where they stand."
Meanwhile, the council also voted on the future of Mr Poole in a closed meeting that lasted about three hours, after interviewing candidates for his position, including Mr Poole, earlier this week.
Ms Wade-Brown refused to answer questions about the outcome of the meeting last night.
If Wellington City Council were to change its stance on the Basin Reserve flyover, NZTA said it might reconsider a number of roading projects in response.
Current transport projects involving the council and NZTA include:
Public transport spine study evaluating light rail and bus options from the Railway Station to Wellington Airport, due 2013. Cost: $1 million.
Airport to Mt Victoria Tunnel, including widening Ruahine St, installing traffic signals at the intersection with Wellington Rd and duplicating the tunnel. To cost about $217m.
Terrace Tunnel upgrade, including a duplicate tunnel, no dates set. Estimated cost $152m.
- The Dominion Post