What is a BDAR, and when is one required?
A Biodiversity Development Assessment Report is a formal assessment under the NSW Biodiversity Conservation Act 2016. It's required when a development is likely to significantly affect threatened species, populations, ecological communities or their habitats, or when the project triggers entry into the Biodiversity Offsets Scheme. It's prepared by an accredited assessor applying the Biodiversity Assessment Method (BAM).
Why are some surveys seasonal?
Many threatened species are only detectable at particular times — when they're flowering, breeding, or active. The BAM requires that survey timing, method and effort follow the relevant NSW survey guides, and that the BDAR documents and justifies them. You can't simply state that surveys were done to the guides; the report must record when, how, and with what effort, including field data. That means a survey done in the wrong season may not satisfy the assessment at all.
What happens if you miss a survey window?
If the optimal window for a target species has passed, you generally wait for it to come around again. Which can mean a delay of months. On a project with a fixed delivery commitment, that's the kind of slip that's almost impossible to recover, and it's entirely avoidable with early planning. It can also underrepresent the species on site, causing it to appear more vulnerable than it is in the local area.
How do you plan around survey windows?
Identify the likely target species and their survey windows during feasibility, before the program is locked. Done well, targeted seasonal surveys do more than tick a box: assessing species by their actual ecology can narrow the impact footprint and reduce offset liabilities, rather than assuming every species is present everywhere. The earlier biodiversity constraints enter the planning conversation, the better the outcome; for the program and for the cost.
The bottom line
On any NSW project with biodiversity triggers, treat survey timing as a scheduling constraint from day one. Booking the right surveys in the right season keeps ecology off your critical path.
Frequently asked questions
Can BDAR surveys be done at any time of year?
No. Many threatened-species surveys must be carried out in specific seasons when the species is detectable, and the Biodiversity Assessment Method requires the BDAR to document and justify survey timing, method and effort. A survey done in the wrong season may not satisfy the assessment.
What is a BDAR?
A Biodiversity Development Assessment Report — a formal assessment under the NSW Biodiversity Conservation Act 2016, prepared by an accredited assessor, required when a development is likely to significantly affect threatened species or triggers the Biodiversity Offsets Scheme.
This article is general information, not project-specific advice. Approval requirements vary by council and by site. Book a project review for advice on your project.