The City Rail Link’s work on the Waitematā Station (Britomart) in Auckland has been awarded a ‘Leading As Built’ rating, an independent verification of the project’s outstanding sustainability outcomes, from the Australian-based Infrastructure Sustainability Council.
The achievement follows the “Excellent As Built’ and ‘Leading Design’ ratings awarded earlier for CRL works at the lower end of Albert St, as well as a wide range of honours for innovation, sustainability, engineering and circular economy practices bestowed upon the project.
The Waitematā works involved the construction of twin 136m-long tunnels under the Chief Post Office, a protected historic building, and lower Queen St and the reinstatement of the surrounding urban realm. The works were conducted by the Downer/Soletanche Bachy (DSB) joint venture, while design works were conducted by Aurecon, Mott MacDonald, Grimshaw, Jasmax and Arup.
CRL chief executive Dr Sean Sweeney acknowledged the work of the contractors at Waitematā and the Link Alliance, which has also adopted ISC sustainability guidelines in the design and construction of the project’s main contract for delivery of tunnels and stations.
“CRL is what I believe is New Zealand Aotearoa’s highest value employment project, bringing big changes to the construction industry,” he said. “During the year we continued to use the scale and complexity of the project to demonstrate our ability to have a positive impact on the wider industry.”
The Waitematā works will result in a 17.8 per cent reduction in peak operational energy use and 23 per cent reduction in operational carbon emissions over the project’s 100-year lifespan. In terms of the project’s aspirational goal of zero waste to landfill, 100 per cent of spoil, 97 per cent of construction and demolition waste and 74 per cent of office waste was diverted from landfill.
“These are meaningful and tangible results that reflect our commitment to sustainable infrastructure construction and, given CRL’s 100-year lifespan, will benefit Aucklanders for generations to come,” Sweeney said.
Downer environment sustainability manager Sarah Sutherland said achieving the highest IS-rated project in Aotearoa was a great accomplishment: “This success was built on the collaborative relationship between CRL and the DSB joint venture and underpinned by the strong sustainability culture set by our senior leaders,” she said.
“It is our earnest hope that by setting the bar high, we provide the inspiration for construction projects that follow to achieve even better, more sustainable outcomes.”
The Link Alliance’s construction of the tunnels and stations is already delivering significant benefits, such as reducing the embodied carbon of the concrete used by substituting fly-ash for cement, as well as energy efficient station designs that include minimising lighting and ventilation energy use.
Works across the Waitematā Station (contract 1) and tunnels and stations (contract 3) have seen more than 16, 785 tonnes of construction demolition diverted from landfill for recycling or reuse during the financial year. Across CRL contracts, 1,415,841 tonnes of waste, including spoil, have been diverted to date.