One of five REZs announced in NSW, the Central-West Orana REZ is a priority for the NSW Government. The project would enable 4.5 gigawatts of new network capacity to be unlocked by approximately the late-2020s. It would enable renewable energy generators such as solar and wind farms to access new transmission infrastructure within the Central-West Orana REZ to export electricity to the NSW transmission network.
New transmission infrastructure needed to connect the REZ
The Energy Corporation of NSW (EnergyCo) is responsible for coordinating the REZ’s transmission, generation and storage projects. To bring the Central-West Orana REZ into reality, EnergyCo is directly responsible for planning and delivering the transmission infrastructure. The transmission infrastructure proposed comprises around 90 kilometres of twin double circuit 500 kV transmission lines and associated infrastructure to connect the two energy hubs to the existing NSW transmission network via the New Wollar Switching Station, and around 150 kilometres of single circuit, double circuit and twin double circuit 330 kV transmission lines, to connect renewable energy generation projects within the Central-West Orana REZ to two energy hubs.
To secure approval for the construction and operation of the transmission infrastructure, and to develop a project that minimises impacts on environmental and social values, EnergyCo engaged WSP to prepare the environmental impact statement (EIS). Preparation of the EIS involved a range of environmental disciplines as well as planning and environmental expertise. WSP undertook extensive field investigations, including biodiversity and cultural heritage surveys to support the EIS, and associated consultation with landowners and Aboriginal stakeholders. WSP also provided key information on the project area’s geotechnical characteristics and contamination status.
This large-scale and challenging project not only covered a very large physical area for fieldwork, but also required our teams to navigate a complex regulatory landscape, including considerable engagement with the government agencies responsible for biodiversity, cultural heritage and other major environmental issues. Our teams relished the opportunity to bring their expertise to support the project’s environmental, social and technical outcomes.
WSP investigates biodiversity and social impacts and opportunities
One of the early challenges in preparing the EIS was that the transmission corridor was as yet subject to refinement as part of the consultation process. Our team collaborated closely with EnergyCo to advise on environmental constraints and opportunities to inform the final alignment of the transmission corridor. WSP worked collaboratively as part of a multidisciplinary team including engineering, property and stakeholder engagement to achieve the optimum project alignment and design. We reviewed previous studies and desktop data and information to inform and advise on corridor route selection and developed a broad assessment approach for preliminary evaluation of impacts while maintaining flexibility for corridor refinement.
Our biodiversity and social impact assessments are a key input for the project’s EIS, required under legislation. With the project located in a region that includes some of Australia’s most important ecosystems, it was vital to understand the likelihood of occurrence of important biodiversity such as threatened ecological communities and threatened species in the project study area, and to avoid impacts to these important biodiversity locations as much as possible.
Through seasonal and targeted surveys, WSP’s ecologists identified the occurrence of a number of threatened flora and fauna species as well as important biodiversity values in the study area including protected areas, wetlands and key habitat areas within the project study area.
The results of these biodiversity studies helped to ensure that important biodiversity factors were avoided to the greatest extent possible. Any unavoidable impacts will be offset with permanent protection and management under biodiversity stewardship agreements. As part of our role in preparing the EIS, we are providing expert advice through our national biodiversity lead on the offsets required, their likely cost, and the development of stewardship sites.
To build a clearer understanding of potential impacts and benefits on local and regional communities associated with the project, WSP prepared a two-phase Social Impact Assessment (SIA) to support the project’s EIS. The study provided an in-depth understanding of the project’s social environment, which included identifying the relevant local and regional social localities, key communities and potentially affected people.
Consultation with more than 44 community members and key stakeholders provided further insight into the existing social environment. Consultation also allowed the SIA team to identify and further discuss community concerns, aspirations, potential impacts and benefits associated with the project with those likely to be directly and indirectly affected.
The SIA team then undertook a comprehensive assessment of potential social impacts and benefits informed by research and consultation and proposed relevant mitigation and enhancement measures for each identified impact and benefit.
A range of other studies was also undertaken including extensive cultural heritage investigations that involved around 5 months of field investigations and archaeological investigations with representatives from local Aboriginal communities. Visual impacts were also assessed, involving extensive fieldwork, substantial use of innovative graphical material, and close collaboration with the NSW Department of Planning Housing and Infrastructure (DPHI) to ensure agreement over the rapidly evolving assessment approach for visual impacts.
Understanding ground and water conditions informs planning and design
The project area encompasses a wide variety of terrain, with complex geology and various soil and rock types. This demanded geotechnical site investigations of a large scale and with significant logistical challenges.
To support the project’s design development, WSP was engaged to undertake geotechnical and contamination investigations. These involved drilling of 77 boreholes and 21 large-diameter boreholes, 6 electrical resistivity tests, 5 surface water tests, excavation of 15 test pits, and installation of 11 groundwater monitoring wells across greenfield sites and rural properties, within local and state road reserves, and at an active mine site where energy hub sites and transmission alignments were proposed.
Our team’s well-developed and flexible working processes enabled us to quickly adapt to changing site conditions, overcome site access challenges, ensure resources were available as needed, and work effectively with well-equipped and experienced subcontractors to deliver high-quality data.
An on-site field manager oversaw all aspects of the investigation, including overseeing subcontractors and field engineers, liaising with property owners, marking out investigation locations, and providing daily progress updates. Samples collected during the investigation were temporarily stored on site and transported to the laboratory at the end of each working shift for testing.
Our resulting geotechnical and contamination factual reports provided a robust indication of the subsurface conditions at each of the proposed infrastructure sites to inform the EIS, other planning approval requirements and the reference design.
Understanding the full picture enables next steps
WSP provided EnergyCo with detailed and reliable information on a range of matters and delivered high-quality EIS documentation necessary to progress the Central-West Orana REZ transmission project through its planning and approvals stages. Since exhibition of the EIS, WSP has provided ongoing support to EnergyCo, including delivering a submissions report that addressed over 400 complex community and stakeholder submissions; an amendment report that documented and assessed a range of post-exhibition design changes and ongoing advisory support.
Following approval of the project by the NSW Planning Minister in late June 2024, WSP will continue to provide environmental assessment, biodiversity and other associated advisory services in the lead up to project construction in late 2024.
It's a solid start for this vital Future Ready infrastructure project, set to transform NSW's energy landscape.
Expected REZ network transmission infrastructure capacity
At least 4.5 GW of transmitted electricity.
Construction start
2024 (est)
Construction complete
2028 (est)
New construction jobs
The project is expected to support a significant number of construction jobs, with estimates reaching around 5,000 jobs at its peak.
It is anticipated to bring lasting economic benefits, attracting up to $20 billion in private investment by 2030 and fostering a sustainable energy future for NSW.
REZ and transmission project size
Total area of the CWO REZ 20,000 km2
Around 90 kilometres of twin double circuit 500 kV transmission lines and around 150 kilometres of single circuit, double circuit and twin double circuit 330 kV transmission lines, plus associated Energy Hubs and switching stations.
Voltage
330 kV and 500 kV
At WSP, we’re taking energy evolution forward by accelerating the path to an energy-secure future. It is time to rethink how we plan, design and engineer our places and energy systems.
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