Tunnels cause worry for Unitec

Owners of the two student apartment blocks want the Transport Agency to buy them before work on the Waterview tunnels starts. Photo / Richard Robinson

Auckland's Unitec tertiary institute wants the Transport Agency to build alternative accommodation for students if they are forced from apartment blocks above the proposed Waterview motorway tunnels.

Owners of the two buildings, housing 137 students in Great North Rd, want the agency to buy them before making them potentially uninhabitable during a five- to six-year construction period which could start in October.

The agency intends taking subterranean property titles beneath the apartments and to lease land next to them from their owners to establish a construction yard above Oakley Creek, but has refused to buy the buildings.

Unitec, in a brief of evidence prepared for a fast-tracked consent hearing next month, says the agency acknowledges the students may need to be moved temporarily while the twin tunnels are bored.

Chief finance officer Paul Conder says if there is any need to move the students, who live in 35 apartments leased to the technology institute, the agency should provide alternative purpose-built accommodation on Unitec's grounds.

That would ensure study routines were not disturbed unduly while retaining the viability of campus accommodation, which he called a prerequisite for attracting the international students Unitec needed.

Apartment owner George Richardson, a director and shareholder of a company which developed the two blocks nine years ago, accuses the agency of an abuse of power over its $1.75 billion Waterview project - which includes widening the Northwestern Motorway and building a 4.5km half-tunnelled link from State Highway 20.

"We do not oppose the creation of the SH20 extension but are seriously concerned at the lack of consultation and the cavalier attitude taken by NZTA [the agency] in respect to our concerns about the direct impact the construction of this road will have on our property and the tenants living there," he says in a statement of evidence for the hearing. "The collateral damage must be managed."

He said the owners were contractually obliged to provide tenants with "quiet enjoyment" of the property, around which they had planted 3000 native shrubs and trees, but which would be upset by light and noise from the construction yard just 8m from bedrooms and by vibrations from a 24-hour tunnelling operation below.

Mr Richardson said the project had made Unitec unwilling to exercise a right of renewal of its lease next year.

"If NZTA does not acquire the property it will place an unsustainable financial burden on the 35 individual owners," he said.

"The effects from noise, vibration and settlement, dust and fumes will have a direct and daily effect on our property and tenants for at least six years.

"The construction site will change an idyllic tranquil vista into a heavy industrial centre - heaven turned into hell."

He said there were many examples of tunnel collapses around the world and the Transport Agency had very little experience of managing such a project.

Agency documentation showed the apartment buildings at "medium" risk from tunnelling while estimating a safe distance from the tunnels of 6m - but with a caveat that without specific testing, vibration prediction models had a 100 per cent margin for error.

That meant the risk could range from half to double the estimate.

Mr Richardson said if the agency bought the apartments, and was able to manage the project well enough to avoid any damage, it should have no difficulty selling them later.

"If it is certain of the efficacy of its reports then it should take the risk and not try to divest it to innocent bystanders."

Agency regional director Stephen Town said world-class contractors with extensive tunnelling experience would apply "the appropriate, safest and proven technology and methods".

Extensive monitoring of nearby structures would be undertaken in accordance with consenting conditions from the board of inquiry, there would be more ground tests before digging, and the agency would mitigate any project impacts.

The tunnels would be at least 20m under the apartments and a safe walkway would give the students access to Unitec.