Some serious weeds are required by law to be controlled by all landholders in an area. These are known as noxious weeds and the law that controls these in NSW is the Noxious Weeds Act 1993.

Weeds that are declared noxious are those weeds that have potential to cause harm to the community and individuals, can be controlled by reasonable means and most importantly, have the potential to spread within an area and to other areas.

A weed is declared noxious because its control will provide a benefit to the community over and above the cost of implementing control programs.

Many ‘bad’ weeds do not meet the criteria for declaration. Noxious weeds will have limited distribution with the potential to become more widespread and will cause impact on agriculture, human health or the environment.

In New South Wales the administration of noxious weed control is the responsibility of the Minister for Primary Industries under the Noxious Weeds Act 1993. The Act is implemented and enforced by the Local Control Authority (LCA) for the area, usually local government.

The Act imposes obligations on occupiers of land to control noxious weeds declared for their area.