BAM Changes - Developer Implications
The NSW Government has released draft changes to the Biodiversity Assessment Method, the scientific method underneath the Biodiversity Offsets Scheme.
The draft changes aims to bring the evidence a project needs for assessing and addressing the impact to the front of the project cycle.
It also seeks to reduce reliance on assumed outcomes and asks for more data driven analysis to support assessment.
The result is that biodiversity decisions that seek to avoid impacts need to be fully documented in early project planning.
Avoidance now has to be genuine, and shown
The Biodiversity Assessment Method has always followed a hierarchy of:
Avoid
Minimise
Offset
The draft requires avoidance to be genuine and puts a standard behind the word. Avoid and minimise measures must now be tested against a standard, which is:
it directly responds to biodiversity values identified in Stage 1
it can be demonstrated to reduce the predicted or actual impact of the proposal on biodiversity values and
it is evidence-based. For example, peer-reviewed publications, best practice or successful industry examples.
This results in developers needing to think about avoidance before a footprint is even decided.
Avoid and minimise measures taken at rezoning can be brought into the assessment as supporting context, where they are relevant and reliable. It’s even more important to capture that early thinking to improve the approval process.
The upside of genuine avoidance is that it will reduce the residual impact of the development and mean fewer credits required reducing the offset liability.
More vegetation is caught by the offset requirement
Offsets are required on native vegetation that is assessed on a vegetation integrity (VI) score. This score is used as a threshold of what is needed to offset based on the proposed impacts.
The draft proposes altering this minimum threshold.
Offsets would now be required for all native vegetation with a vegetation integrity score of 15 or above and the old separate thresholds at 17 and 20 are gone.
This simplifies the assessment method but may lead to more vegetation falling into the offset requirement.
For a proponent, that means understanding the offset position the site, earlier, rather than assuming lower-condition vegetation will pass.
You may have to survey where you once assumed
Determining whether a threatened species is present has always had three options: a targeted survey, an expert report, or assuming presence.
The draft turns those into a hierarchy that has to be followed in order:
targeted survey
expert report
assumed presence
Moving down the order now has to be justified, where before any option could be chosen.
For a developer, that can add survey cost and time at the front of a project, and surveys can be seasonally constrained. But assuming presence always booked a worst-case impact.
Where a survey shows a species is not there, the offset obligation can come down.
The change trades an up-front survey cost for a more accurate, and potentially lower, credit liability at the end.
The assessment area gets bigger for linear projects
Every assessment includes a buffer, the area assessed around the impact site.
The draft standardises that buffer to 1,500 metres for all proposals and removes the old 500 metre buffer that applied to linear-shaped proposals.
For a road, a transmission line or a pipeline, that is a substantially larger area to assess and more potential biodiversity value drawn into the picture.
Anyone scoping a linear project should assume a wider assessment footprint than before.
Prescribed impacts have been added to
Prescribed impacts are specific impacts the method requires to be assessed, beyond direct clearing. They include direct and indirect impacts:
on the habitat of threatened entities, including geological features such as karst, caves, crevices, cliffs, rocks and rock outcrops, human-made structures, and non-native vegetation
on areas that connect threatened species habitat, such as movement corridors
on water quality, water availability, water bodies and hydrological processes that sustain threatened entities, including impacts from subsidence or upsidence due to underground mining
from wind turbine strike on protected animals
from vehicle strikes on threatened fauna species, or fauna that are part of a threatened ecological community
The draft adds a further prescribed impact:
from vibration and blasting associated with development
For a developer, that means a project which blasts now carries an assessment step it did not before.
Water availability has also been brought into the water impact.
These additional impacts are worth noting as they can impact project approval.
Partial loss has been tightened
When a development impacts vegetation, the loss is recorded as either a full loss, where the vegetation is treated as gone, or a partial loss, where some but not all of the biodiversity values are impacted and the vegetation is left in a lower condition.
Partial loss produces a smaller calculated impact than full loss for the same area, and so a smaller offset obligation.
The draft narrows when partial loss can be applied. It now:
must be evidence-based
cannot be used where vegetation is removed and then regenerates
cannot be used where suitable threatened species habitat is removed
Before, partial loss could be applied more freely to soften the calculated impact of proposed works.
The draft closes that off in the situations where an impact is really a full loss.
Where it genuinely applies it still reduces the credits required, but the call now has to be backed by evidence, and it cannot be used to discount clearing that removes the vegetation or the habitat outright
Offsetting can be staged
An offset obligation is normally acquitted in full, with all the required credits retired to cover the project's impact.
The draft adds a provision that allows the offset requirement for direct impacts to be staged rather than met all at once.
For a developer, that changes when the offset cost falls.
Staging lets the obligation track the phases of the build, so the credit spend follows the development rather than landing as a single cost at the start.
On any project big enough to be delivered in stages, that is a genuine cash-flow benefit, and it is worth factoring into how a project is sequenced and financed.
When it takes effect
Once the updated method is published, a twelve-month transition applies:
a report can be certified under either BAM 2020 or
the updated method, and a BAM 2020 report can be amended under the old rules for up to two years.
Timeline
Have your say. The draft updated BAM and consultation paper are open for submissions until 11:59pm on 10 October 2026. Full details and the feedback form are here.
