Hancock Energy submits Belisama gas project to WA EPA with focus on horizontal directional drilling and avoidance

Environmental Approvals for the Belisama Gas Project

Hancock Energy has submitted a formal environmental application to the Western Australian Environment Protection Authority (EPA) for the Belisama gas project, a proposed central processing facility (CPF) and pipeline network located approximately 350 kilometres north of Perth. The application, lodged for assessment under Part IV of the Environmental Protection Act 1986 (WA), outlines a major piece of gas infrastructure intended to function as a regional hub for surrounding developments. What distinguishes this proposal from many of its predecessors is the extraordinary disparity between the total development envelope and the actual physical disturbance footprint: a 1,326.9-hectare envelope has been engineered down to a 291.5-hectare disturbance area, with native vegetation clearing restricted to just 5.7 hectares.

For environmental planners, project ecologists, and infrastructure proponents working across Western Australia, this application represents a contemporary benchmark in how impact avoidance is being built into project design rather than managed after the fact. The WA EPA has long required proponents to demonstrate rigorous application of the mitigation hierarchy under its assessment process, but the Belisama project is notable for the degree to which avoidance engineering has been embedded at the feasibility and preliminary design stage. The use of horizontal directional drilling (HDD) to traverse sensitive riparian and road corridor areas, combined with formally designated Clearing Exclusion Zones (CEZs), demonstrates a project philosophy centred on avoiding offset liability rather than accumulating it.

For developers, environmental lawyers, and council planners working on linear infrastructure projects anywhere in Australia, this application signals where regulatory expectations are heading. The WA EPA’s assessment pathway under Part IV is well regarded as one of the more rigorous state-level environmental impact assessment (EIA) frameworks in the country. How proponents satisfy that framework, particularly on biodiversity and vegetation impacts, increasingly shapes what is considered acceptable practice in other jurisdictions as well.

Key details of the Belisama gas project application

The Belisama gas project proposes the construction of a central processing facility and associated pipeline network in the Mid West region of Western Australia, approximately 350 kilometres north of Perth. The total development envelope nominated in the application is 1,326.9 hectares. Within that envelope, the physical disturbance footprint has been contained to 291.5 hectares, representing approximately 21.9 percent of the total envelope area. Of that disturbance footprint, only 5.7 hectares involves clearing of remnant native vegetation, with the remainder of the disturbed area comprising existing cleared agricultural land. This design approach dramatically reduces the extent of vegetation clearing that would otherwise need to be justified, offset, or both.

A critical technical mechanism enabling this outcome is the formal designation of 21.8 hectares as Clearing Exclusion Zones. These CEZs are areas of ecologically or hydrologically sensitive land that are explicitly removed from any construction or operational activity. They function as hard constraints on the project footprint rather than aspirational buffers, and their formal designation in the application strengthens the proponent’s avoidance case when the EPA evaluates compliance with the mitigation hierarchy. In practical terms, CEZs require that project engineers and environmental specialists work together during the preliminary design phase to identify sensitive receptors and lock them out of the design before detailed engineering commences.

Horizontal directional drilling is the primary engineering method used to avoid surface disturbance at the most sensitive locations along the pipeline route. The application specifies that HDD will be deployed to cross Sand Plain Creek, Yandanooka West Road, and Mt Adams Road. Sand Plain Creek represents a riparian corridor where open-cut trenching would cause direct vegetation clearing, soil disturbance, and potential hydrological disruption to a watercourse. By boring beneath the creek using HDD, the pipeline traverses the corridor without any surface works in the riparian zone. Road crossings at Yandanooka West Road and Mt Adams Road are similarly handled trenchlessly, preserving road integrity and avoiding the need for reinstatement works that frequently introduce secondary disturbance risks.

The application is being assessed under Part IV of the Environmental Protection Act 1986 (WA), which governs proposals with the potential to have a significant effect on the environment. Part IV assessments can result in conditions attached to Ministerial approval, including conditions relating to clearing limits, offset requirements, management plan obligations, and ongoing monitoring and reporting. By substantially reducing the native vegetation clearing footprint at the design stage, Hancock Energy is materially reducing the scope and cost of any offsets that may be required as a condition of approval, as well as simplifying the pathway through the EPA’s formal assessment process.

Australian context: WA EPA expectations and national implications for linear infrastructure environmental impact assessment in Western Australia

The Western Australian EPA operates one of Australia’s most structured environmental impact assessment frameworks for major proposals. Under Part IV of the Environmental Protection Act 1986 (WA), proponents are required to apply the mitigation hierarchy in order: avoidance first, then minimisation, then rehabilitation, and finally offsets as a last resort. The EPA’s Environmental Offsets Policy (2011) and associated guidelines make clear that offsets are not an alternative to avoidance but a residual mechanism for impacts that genuinely cannot be avoided or minimised through design.

References and related sources

• Primary source: petroleumaustralia.com.au

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This is an iEnvi Machete news summary. Prepared by iEnvi to summarise the source article for contaminated land, groundwater, remediation, approvals and site risk professionals.

Published: 08 May 2026

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