The Five-Part Test of Significance Explained: What It Means for Your Development Application in NSW

If you have received advice that your development application in NSW requires an ecological assessment, there is a good chance you will encounter the Five-Part Test of Significance. This test is a cornerstone of NSW biodiversity legislation and plays a central role in determining the level of ecological assessment your project requires. Understanding what it is, how it works, and what the outcomes mean for your project is essential for any developer, builder, or landholder navigating the approval process.

What Is the Five-Part Test of Significance?

The Five-Part Test of Significance, also known as the Test of Significance, is set out in Section 7.3 of the Biodiversity Conservation Act 2016. It is the statutory test used to determine whether a proposed development or activity is likely to have a significant impact on threatened species or ecological communities listed under the BC Act. The test is applied as part of a Flora and Fauna Assessment (FFA) and examines five specific factors relating to the ecology of the species or communities that may be affected.

The Five Parts Explained

Part (a): Population Size and Viability

This part considers whether the proposed development is likely to have an adverse effect on the life cycle of the species such that a viable local population of the species is likely to be placed at risk of extinction. The assessment considers the size and connectivity of the local population, the importance of the habitat on the development site to that population, and whether the proposed impact would reduce the population's ability to survive and reproduce.

Part (b): Habitat and Occurrence

This part examines whether the proposed development is likely to have an adverse effect on the habitat of a threatened species, population, or ecological community such that the local occurrence of the species, population, or ecological community is likely to be placed at risk of extinction. It considers the extent, condition, and connectivity of the habitat to be impacted.

Part (c): Movement and Genetic Exchange

This part assesses whether the proposed development is likely to adversely affect the movement of the species between important habitat areas, or reduce genetic exchange between known populations. It is particularly relevant for species that rely on habitat corridors or connectivity between patches of habitat, such as koalas and gliders.

Part (d): Key Threatening Processes

This part considers whether the proposed development is likely to have an adverse effect on any declared area of outstanding biodiversity value, either directly or indirectly. It also considers whether the proposal will introduce or increase a key threatening process listed under the BC Act, such as clearing of native vegetation, removal of hollow-bearing trees, or introduction of invasive species.

Part (e): Extinction Risk

The final part considers whether the proposed development is likely to significantly increase the extinction risk of the threatened species, population, or ecological community. This is a cumulative consideration that takes into account the current conservation status of the entity, existing threats, and the additional pressure that the proposed development would add.

What Happens If a Significant Impact Is Identified?

If the Five-Part Test concludes that a significant impact is likely on any threatened species or ecological community, the project must enter the Biodiversity Offsets Scheme. This means a Biodiversity Development Assessment Report (BDAR) will be required, prepared by an accredited assessor using the Biodiversity Assessment Method (BAM). The BDAR will calculate the biodiversity credits needed to offset the impacts of the development.

If the test determines that no significant impact is likely, the Flora and Fauna Assessment with the completed Five-Part Test is typically sufficient to satisfy the ecological assessment requirements of the development application. This is the more straightforward and less costly outcome.

Getting the Test Right Matters

The Five-Part Test requires careful ecological judgement and a thorough understanding of the species and communities in question. A poorly prepared test can lead to incorrect conclusions, either triggering unnecessary entry into the BOS or, conversely, failing to identify a genuine significant impact which may result in the DA being refused or challenged. At Ecological Solutions, our experienced ecologists ensure the Five-Part Test is applied rigorously and defensibly for every project.

If you need an ecological assessment for your NSW development project, contact Ecological Solutions to ensure the Five-Part Test is prepared correctly from the outset.