Wilman Wadandi HighwayDelivering a safe and efficient road network along with social outcomes to the South West

A Local Business Advisory Group (LBAG) was established to ensure that local businesses had input to the project’s timeline and procurement strategy. This group led the formation of the project’s “inside out” local procurement strategy that prioritised businesses genuinely based in the region by using a Local Weighting table. The table defined the five different ‘categories’ of being considered as a local business, with weighting given to businesses that were established, owned and operated in the region.

A community hub in the centre of Bunbury was established that allowed community members, including job seekers and businesses, to speak directly with Alliance employees about opportunities on the project and be informed of its progress. A large satellite map of the project and an interactive visualisation of how the highway would function were part of the information on display, ensuring all community members felt informed and connected to the project.

Local and Aboriginal business procurement targets were exceeded, with contracts appointed across 390+ local suppliers^*.

The South West’s longest bridge

The project features 11 bridges, including a 382-metre ‘mega-bridge’ that overcame complex challenges to reduce materials use and remain sensitive to the environment. With 12 bridge spans varying between 23.8 metres and 43.3 metres, it provides a clear crossing over the environmentally-significant Ferguson River. A vertical clearance of 7.3 metres over the freight rail corridor was achieved, and the number of abutments required reduced from six to two – resulting in a 22 per cent reduction in concrete volume.

The project introduced Western Australia’s first use of large, bored mono-piles, together with an integral bridge design at the route’s ‘Y’ Interchange to minimise maintenance and maximise efficiency.

This is significant because, by using bored mono-piles up to 2.2 metres in diameter, this eliminated the installation of numerous smaller piles and pile caps – often large and heavily reinforced – and meant the piles terminated underside at deck level with a headstock. The headstock was precast which eliminated onsite formwork and falsework requirements at height (approximately 6 metres above ground level).

Pioneering sustainable materials and environmental initiatives

A number of trials pioneering the use of sustainable materials was undertaken on the highway project. This included pipes from 100 per cent recycled plastic, mostly household milk and juice bottles, forming part of the project’s drainage network. A total of 66 metres of the recycled pipe was laid, with each pipe 6 metres in length and 37.5 cm in diameter, with the benefit of a 100-year product life.

An eco-friendly substitute for traditional cement concrete, geopolymer concrete from locally stored fly ash was used in concrete blocks along the route. A lower-emission alternative, this was a demonstration project for the product for wider market applications.

The project pioneered trials of sustainable materials including recycled plastic pipes, low-carbon concretes, and Food Organics Garden Organics in mulch for erosion control. Wildlife connectivity and habitat protection was achieved with fauna bridges and underpasses, revegetation of 335 hectares, and long-term conservation sites.