The Coffs Harbour bypass project team has celebrated being awarded the highest possible Infrastructure Sustainability (IS) Design rating.
Transport for NSW Snr Manager Environment & Sustainability, Scott Lawrence, said that this independently verified rating was awarded to the project after examining its economic, social and environmental performance in the design phase.
“This is an excellent result with the project receiving the IS design rating of 86.39, which is the culmination of lots of hard work by Transport, the major construction contractors Ferrovial Gamuda Joint Venture and the design partners Arcadis,” Lawrence said.
“This result has not only exceeded our contractual requirements for the project, it’s also exceeded the Minister’s Conditions of Approval.
“Our team managed to bring together a series of stakeholders to achieve our aligned goal of sustainable delivery, which included reducing carbon emissions, conserving water, reducing the project footprint, preserving local heritage and bringing innovation to the methods used across the alignment.
“Sustainability is more than simply looking at ways to reduce our emissions, although that’s been a significant part of how we’ve received this rating by preserving local native vegetation, reducing the overall construction footprint, and replacing concrete noise walls with lower embodied carbon content material that has very good noise attenuation properties.”
The bypass has also undergone a robust risk assessment to inform a resilient design that measures up to the most extreme climate change scenario. This includes ensuring culverts, bridges and scour protection measures take into account predicted increased storm intensities as well as the optimisation of pavements to withstand increased frequencies of heatwaves.
Lawrence said that designing high efficiency sediment basins to capture and reuse water also contributed to the high design rating.
“Our sediment basins, designed and used first right here on the bypass project, have shown impressive results during recent high rainfall events, reducing by 78 per cent the debris and heavy metals released by a standard sediment basin.”
Lawrence said the team managed to reduce the amount of concrete used on the bypass by utilising material with lower embodied carbon content that has high noise attenuation properties in the sound barriers as well as using high density polyethylene (HDPE) pipes where possible.
“The HDPE pipes are both lightweight and strong, and made from a recyclable material that’s tough, impact-resistant and can withstand extreme temperatures,” Lawrence said.
“The project’s also rated well with our pavement design using a mix that requires less total volume of asphalt but still meets the strict quality control standards required of freeway traffic environment.
“Both the bypass team at Transport and its contractors, Ferrovial Gamuda Joint Venture, are thrilled at this rating and will seek to share these innovations and improvements with other major infrastructure projects across the state and around the country.”
More information about the Coffs Harbour bypass project is available on the project page at https://www.nsw.gov.au/driving-boating-and-transport/projects/coffs-harbour-bypass
