M1 Pacific Motorway Upgrade Varsity Lakes to Burleigh

The project has calculated a total GHG emissions reduction of 18% across the infrastructure lifecycle, when compared to the Base Case. Several initiatives contributed to a significant reduction in diesel fuel consumption and associated construction time, including the retention of the existing Reedy Creek Flyover, pavement rubblisation and re-use of site won material (including ACM contaminated material). 

A 16% reduction in materials usage for the materials lifecycle (when compared to the Base Case) achieved through initiatives including the retention of the existing Reedy Creek Flyover and use of Stone Mastic Asphalt (SMA) and EME2. 

Significant terrestrial and aquatic ecological enhancements including removal of all weeds from within the road reserve disturbance footprint and replacement with locally indigenous native plant species, planting of 30 endangered Richmond Birdwing Butterfly vines (Pararistilochia praevenosa), host plant for the larvae of the endangered Richmond Birdwing Butterfly (Ornithoptera richmondia) into Jack Ross Park as part of the invertebrate sensitive highway design, Plating of 1,960 Saw sedge (Gahnia clarkei) plants across the site which are the host plant for the larvae of the locally endangered Swordgrass brown butterfly (Tisiphone Abeona) to encourage its re-introduction to the area as part of the invertebrate sensitive highway design and the planting of large areas of suitable habitat for key endangered fauna species and improvement to sensitive waterways, riparian areas and aquatic habitats. 

This method involves the re-use of existing concrete base in-situ. The sustainability benefits are: 

• Reduction of approximately 8,765 m3 of waste to landfill and associated greenhouse gas emissions; 

• Reduced impact on the local traffic, as fewer trucks would be required to remove waste from site; and 

• Reduction in construction time and associated greenhouse gas emissions. The concrete fracturing machine is anticipated to be 7-8 times more productive than the conventional 20t excavator. For existing pavement around 200-250mm in thickness,  it is expected that the concrete fracturing machine can rubblise around 6,000 m2 per 9-hour shift. Whereas, a 20 t excavator can only break the existing concrete into large blocks up to 800 m2 per 9-hour shift. 

The targeted species include the Richmond Birdwing Butterfly (vulnerable in QLD), the Swordgrass Brown Butterfly (vulnerable in NSW), Spotted Sedge-skipper, Painted Sedge-skipper, as well as several other species that are at risk of local extinction within Gold Coast. 

The aim of this initiative was to plant flora species that specifically targeted the abovementioned invertebrates to alleviate the adverse impacts from habitat loss and fragmentation on their survivability. 

The following flora species (or ‘host plants’) that were planted include: 

• 30 x Birdwing Butterfly vines – Host plant for the Richmond Birdwing Butterfly  

• 1,961 x Gahnia clarkei – Host plant for the Swordgrass Brown Butterfly and plant food for the Painted Sedge-skipper 

• Additional nectar plants for adult Richmond Birdwing Butterflies were included as part of the landscaping mix of shrubs and trees. 

The intent is to collect the actual data from projects utilising this tool and to: 

• Improve waste estimates for future projects; 

• Gain a further understanding of waste generated by construction projects; and 

• Potentially encourage more circular economy practices. 

The project recognised that road and culvert crossings are some of the main barriers to fish migration up and down waterways, and the purpose of this initiative was to prevent habitat fragmentation and therefore ensure that the fish and other aquatic species were able to move within the stream unimpeded. 

Additionally, monitoring data collected from this initiative will be used to analyse the effectiveness of these types of baffles and hopefully influence future design guidelines and drive continuous improvement, and encourage uptake on other infrastructure projects. 

By attending a Climate Change and Risk Assessment workshop at a program level, the project team was able to develop a M1 North and M1 South Climate Change Risk and Adaptation Assessment Report. This was then created as a template for all future TMR projects to use. 

It also led to the development of the following technical guidance and templates: 

• Engineering Policy 170: Climate Change Risk Assessment Methodology 

• Climate Change Risk and Adaptation Assessment Framework for Infrastructure Projects 

• Climate Change Risk Assessment Template 

• Climate Change Risk and Adaptation Assessment Report Template