Not every weed is treated the same way. Some need to be destroyed immediately, while others can be managed or contained. To decide the best approach, weeds are assessed using the Weed Risk Management (WRM) system. The results of the WRM system determines where the weed sits on the Invasion Curve.
Seeds can remain viable for a long time, with some seeds lasting over 100 years in the soil
In Australia, more than 72% of invasive weeds were once garden plants that “escaped” into bushland.
Water weeds like Water Hyacinth and Frogbit can double their size in just a few days, choking waterways.
Weeds cost Australian agriculture an estimated $4 billion every year in lost production and control costs.
Weed risk – how invasive it is, how far it could spread, and the damage it might cause.
Control feasibility – how hard or costly it is to control, how persistent it is, and whether it can be managed across the region.
Each weed is given two scores:
Weed Risk Category (e.g. High, Medium, Low)
Feasibility of Control Category (e.g. Very High, Moderate, Low)
These two scores are combined to set a management priority.
Destroy Infestations – Weeds in this category must be eradicated wherever they are found.
Contain Spread – Control measures aim to stop the weed from spreading into new areas and is assigned into the containment category.
Manage Weed / manage sites – These weeds are usually widespread, so the focus is on reducing their impact and protecting valuable assets. This is typically covered by the General Biosecurity Duty (GBD)
Early action = most effective and affordable.
Delays = higher costs and greater impacts.
Prevention is the Best Defence
Stopping invasive species before they establish is the most cost-effective approach. This involves:
Identifying high-risk species.
Assessing their potential to invade NSW.
Putting up barriers to stop their entry.
Where information is limited, the precautionary principle is applied.
If a new invasive species appears:
Eradication should be the first response.
Success depends on early detection and rapid action.
Targeted, species-specific programs work best at this stage.
Eradication is rarely possible once an invasive species is established across large areas.
Management then focuses on:
Protecting priority assets:
Environment (ecosystems, biodiversity).
Agriculture (food production).
Community (health, infrastructure, culture).
Using a prioritised approach to make the best use of limited resources.
Weed Risk Management (WRM) System ranks weeds to decide priorities.
Pest animals are fewer, but similar prioritisation methods apply.
Regional committees (under the Biosecurity Act 2015) allow landholders andcommunities to set shared priorities.
Monitoring measures the success of management actions.
Data guides where to invest resources for the best results.
Regional plans use the MERI framework (Monitoring, Evaluation, Reporting and Improvement) to adapt over time.
These activities underpin biosecurity by providing:
New tools and techniques.
Stronger monitoring systems.
Community awareness and participation.
Spotted a weed in your area? You can report it using our Report a Weed form by clicking the button below.
When reporting, please include:
A clear photo of the plant (include flowers or seed heads if possible).
Location details – an address, description, or GPS coordinates.
Our Biosecurity Team will contact you to arrange an inspection and confirm the plant's identity.
Report a Weed Form