Hunter Expressway Ecology

Project outline

The 40-kilometre, $1.7 billion, four-lane Hunter Expressway is the biggest infrastructure project currently under construction in NSW and is due to open before the end of 2013.

This major new road will run from north-west Lake Macquarie to Branxton and is anticipated to cut travel times through the Hunter region, reduce the number of heavy vehicles travelling through towns on the New England Highway and to support the growing Hunter region.

Our role

As appointed ecologist for the Hunter Expressway, Niche director Dr Rhidian Harrington’s involvement in the project began a decade ago during the planning and design phase.  For over six years Rhidian managed the ecological components of this project during the design and approvals stages, including targeted flora and fauna surveys, impact assessment, mitigation design, offsets, environmental management plans and a Referral. There were numerous and significant ecological issues on this project and Rhidian worked closely with the RMS engineers during the design phase to minimise any impacts. Rhidian was also required to complete an Environmental Assessment and Species Impact Statement (SIS) for the associated electricity adjustments for this project.

Niche has been involved in the project for over four years in the role of Ecologist as part of the Hunter Expressway Environmental Advisor team. Work has included vegetation mapping surveys, Koala surveys, pre-clearing surveys, fauna rescue, nest box installation, a BioBanking Assessment, offset strategies and technical advice to the Project’s environmental manager.

Rhidian worked closely with the RMS design team to find a solution


One of the biggest challenges on this project was impacts to a highly significant regional wildlife corridor in the Mount Sugarloaf section of the project. This area is one of the most significant areas of remaining vegetation in the Lower Hunter Valley and is one of only a few remaining vegetated links between the Great Dividing Range and the east coast. The original design of cut and fill through three valleys in this section would have resulted in a significant impact on numerous threatened animal species and would have been a major impediment to the approval of the project. Rhidian worked closely with the RMS design team to find a solution to this issue, which resulted in the three viaducts measuring a total of 755 m in length and up to 42m in height being installed. The length and height of the viaducts ensured that the Hunter Expressway would not be an impediment to movement for wildlife through this highly significant wildlife corridor. Due to geotechnical issues and an approvals condition to maintain vegetation clearing below a specified maximum area, the provision of the viaducts provided a cost-effective solution to this very significant problem.


Despite the presence of large areas of Endangered Ecological Communities (about 90% of the vegetation cleared for the project is endangered) and impacts to numerous threatened species (thousands of threatened plants were cleared) the RMS received approval for the project. Although the impacts to biodiversity were large, careful design and mitigation measures minimised these impacts, while a comprehensive offsetting strategy ensured that the project met the ‘maintain or improve’ standard as required by the principals of ecologically sustainable development under the NSW Environmental Planning and Assessment Act.

Rhidian Harrington, Niche Director and Ecologist
Mob: 0488 224 999

Hunter Expressway

Hunter Expressway

Hunter Expressway