Nature conservation

Biodiversity Reform

Serious and irreversible impacts

The concept of serious and irreversible impacts is fundamentally about protecting threatened entities that are most at risk of extinction from potential development. The Biodiversity Offsets Scheme recognises that there are some types of serious and irreversible impacts that the community expects will not occur except where the consent authority considers that this type of impact is outweighed by the social and economic benefits that the development will deliver to the State.

Effect of a serious and irreversible impact

The following table sets out the effect of a serious and irreversible impact for different types of development and activities (if they require assessment under the Biodiversity Offsets Scheme):

Type of development or activityEffect of serious and irreversible impacts
  • Clearing proposals
  • Part 4 development (that is not State Significant Development or State Significant Infrastructure)
The approval authority must not grant approval if they determine the proposal is likely to have a serious and irreversible impact on biodiversity values.
  • State Significant Development
  • State Significant Infrastructure
  • Part 5 activities (where a proponent chooses to opt in to the Biodiversity Offsets Scheme)
  • Biodiversity Certification
The approval authority can approve a proposal which is likely to have serious and irreversible impacts.

The approval authority must take those impacts into consideration and determine whether there are any additional and appropriate measures that will minimise those impacts if approval is to be granted.

Deciding whether an impact is serious and irreversible

The approval authority is responsible for deciding whether an impact is serious and irreversible.

Information about serious and irreversible impacts will be included in the Biodiversity Assessment Report for the proposal. This report must be prepared by an accredited assessor using the Biodiversity Assessment Method.

The approval authority must consider this information to decide whether any impact is serious and irreversible having regard to principles (see below) and the Guidance to assist a decision-maker to determine a serious and irreversible impact (PDF 710 KB) published by the Chief Executive of Office of Environment and Heritage (OEH). This OEH guidance provides criteria and supporting information to assist with the application of these principles and includes a list of threatened entities that could result in a serious and irreversible impact.

Principles for determining serious and irreversible impacts

An impact is to be regarded as serious and irreversible if it is likely to contribute significantly to the risk of a threatened species or ecological community becoming extinct because:

  • it will cause a further decline of a species or ecological community that is currently observed, estimated, inferred or reasonably suspected to be in a rapid rate of decline
  • it will further reduce the population size of the species or ecological community that is currently observed, estimated, inferred or reasonably suspected to have a very small population size
  • it is an impact on the habitat of the species or ecological community that is currently observed, estimated, inferred or reasonably suspected to have a very limited geographic distribution
  • the impacted species or ecological community is unlikely to respond to measures to improve its habitat and vegetation integrity and therefore its members are not replaceable.

These principles are set out in clause 6.7 of the Biodiversity Conservation Regulation 2017.

Thresholds for serious and irreversible impact

The OEH guidance indicates that each potential serious and irreversible impact will have an impact threshold identified. Thresholds will be one of the factors that the approval authority will consider, alongside the information provided in the Biodiversity Assessment Report, in determining whether a serious and irreversible impact is likely to occur.

Impact thresholds for potential serious and irreversible impact (SAII) entities are available in the Threatened Biodiversity Data Collection hosted by Bionet. For other entities, thresholds have not been developed. For example, thresholds have not been assigned to any threatened ecological communities. In the absence of thresholds, the consent authority can disregard references to considering thresholds in the OEH guidance when making their determination.

Page last updated: 12 July 2018