Implementing biodiversity offsetting in alignment with the mitigation hierarchy – the experience of land use planning law in New South Wales

Biodiversity offsetting is firmly established as an integral part of environmental law regimes across the world. Whether offsets are appropriate for a particular development is determined through the application of a mitigation hierarchy. Whilst a rich vein of scholarship exists dealing with the operation of the mitigation hierarchy in principle, the implementation of the mitigation hierarchy has received comparatively small coverage. From a legal perspective this prompts questions relating to the implementation of the mitigation hierarchy as part of the planning law process. This article critically examines the issue in the context of laws regulating biodiversity loss in the state of New South Wales (NSW), Australia. The article contributes to filling this gap through a critical analysis and evaluation of the statutory regime and specific examples of relevant case law in NSW where development applications have been rejected on the basis, broadly speaking, of failing to demonstrate adherence to the requirements of the mitigation hierarchy. The primary findings presented by the article maintain that the extent to which decision-makers can influence and enhance biodiversity protection through implementation of the mitigation hierarchy is inherently limited due to the underlying rationale and values of planning law. While the decisions carry value in terms of showing what might be reasonably expected from developers in terms of demonstrating how their development applications adhere to the mitigation hierarchy, change that has broader application and can be applied in a more objective manner must be provided through legislative or regulatory change. The experience of NSW can offer some lessons for the implementation of biodiversity offsets in different jurisdictions considering the recent 15th Conference of the Parties (COP) on the Convention of Biological Diversity (CBD) and the Kunming-Montreal Global Biodiversity Framework (GBF).