Auckland business leaders are pushing the Government to save more than $1 billion by controversially building the Waterview motorway link across country, rather than through tunnels.
A report sent to Transport Minister Steven Joyce by the Auckland Business Forum is set to unleash furious debate at a time when political parties are preparing to contest a byelection in the local Mt Albert electorate soon to be vacated by former Prime Minister Helen Clark.
Duncan Macdonald, chairman of both the Avondale Community Board and the local business association, said last night that his constituents would not tolerate any alternative to tunnels.
"There's no third option - it's the tunnel or nothing," he declared.
But the forum says a surface link of three motorway lanes in each direction through the electorate could be built for $1.2 billion without overlooking what it calls "major mitigation" including tunnels at key points and ample compensation for property owners.
It has decided against recommending a more basic project using bridges and less generous compensation, at an estimated cost of $950 million, in acknowledgement of what chairman Michael Barnett says would be major community disruption.
The forum has told Mr Joyce to expect a return of $3 for every $1 invested, instead of a benefit of only $1.15 calculated by the Treasury from two-lane tunnels costing $2.77 billion.
A cost blowout of $105 million on an earlier estimate of $1.89 billion, plus a novel decision by officials to add more than $500 million of extra financing costs and $240 million for widening the nearby Northwestern Motorway, prompted the Government in January to order a major project review.
Mr Joyce said in announcing the review he was "not comfortable" with building two-lane tunnels with no ability to enlarge them for future traffic demand, but was concerned at an even higher estimate of $3.16 billion for three-lane structures.
He asked officials to consider all options, including a surface route and previously discarded "cut and cover" proposals.
The business forum has proposed underpasses beneath New North Rd and the western railway line, and a tunnel under the prized Oakley Creek and Gt North Rd to an interchange with the Northwestern Motorway.
But the rest of the 4.5km route would lie above the surface, meaning consideration community disruption from the loss of at least 400 homes as well as parkland through Mt Albert.
Anticipating "political push back" from the community, the forum says the Government should consider paying a premium of about 50 per cent on compensation for homeowners.
It says that as Waterview is the final missing link in Auckland's 48km western ring route between Manukau and Albany, the issue is not whether to build it, but how and how fast.
Mr Barnett acknowledged "a huge burden of social costs" to the project, but said the fact remained that building tunnels was "going to cost another billion dollars and the people of Auckland have to make up their mind if that's what they want".
But Mr Macdonald said the option of not building the link, and leaving State Highway 20 to end at Maioro St in New Windsor, should be considered as the only alternative to tunnels.
"If the Government is of a mind to do it cheaper, then it won't get done," he told the Herald. "I'll have every person living in Waterview and Mt Albert out there stopping it."
"It's been hard enough to talk the people of Avondale, Waterview and Mt Albert into allowing the tunnel."