Noxious is essentially a legal term. Plants are declared noxious under the Noxious Weeds Act 1993 (NWA 1993) if they have significant negative impacts on the economy, community and environment of NSW. Generally, these declarations occur only if the benefit to the community outweighs the likely cost of control. Specifically, a plant is declared noxious if it is controllable by reasonable means and if it has the potential to spread within an area and to other areas.

Declaration provides a legal framework for the control of noxious weeds on both public and private land. A noxious weed declaration gives Council as a Local Control Authority the power to inspect private land for noxious weed occurrence and issue orders for owners or occupiers of such land to control those weeds according to the requirements of the control class in which they occur. Across the State, noxious weed lists include many agricultural, bushland, aquatic, roadside and allergenic weeds.

Traditionally, the majority of declared weeds under the NWA 1993 have been agricultural weeds based on an obvious need to protect agricultural production. Over recent times environmental weeds have gained increased representation on LGA noxious weeds lists. Amendments to the NWA 1993 in 2006 acknowledge the need to lessen the impact that some weeds have on the biodiversity and ecological integrity of vegetation communities and waterways across the State. Not all environmental weeds that occur within the Woollahra LGA are presently declared noxious within the Woollahra LGA but may be considered for inclusion at a future date.

Noxious weeds are declared geographically on Local Government Area basis. Any particular plant may be declared in just one LGA, across a number of LGAs, across a region or across the entire state. Local Control Authorities (most commonly local Councils) can make application to have plants declared as noxious within one of five control classes. Application can also be made to remove plants from a list or to change the control class in which they occur.

There are currently five noxious weed control classes under the Noxious Weeds Act 1993.

Class 1 - State Prohibited Weeds. The plant must be eradicated from the land and the land must be kept free of the plant.

Class 2 - Regionally Prohibited Weeds. The plant must be eradicated from the land and the land must be kept free of the plant.

Class 3 - Regionally Controlled Weeds. The plant must be fully and continuously suppressed and destroyed.

Class 4 - Locally Controlled Weeds. The growth and spread of the plant must be controlled according to the measures specified in a management plan published by the local control authority.

Note: If the plant declared as a Class 4 weed is also considered to have the potential to be sold, propagated or distributed, then Class 4 has the expanded control definition as follows:

“The growth and spread of the plant must be controlled according to the measures specified in a management plan published by the local control authority and the plant may not be sold, propagated or knowingly distributed”.

Class 5 - Restricted Plants. The requirements in the Noxious Weeds Act 1993 for a notifiable weed must be complied with.

A noxious weed that is classified as a Class 1, 2 or 5 is referred to in the NWA 1993 as a notifiable weed. This means, inter alia, that the LCA (Council) must be notified of the presence of such weeds within three (3) days of their detection.

The current list of noxious weeds for the Woollahra LGA and all other NSW LGAs can be found at the NSW Department of Primary industries website.

There is currently a total of 84 plant species declared noxious for the Woollahra LGA within the following Weed Control Classes:

Class 1 - 27

Class 2 - 3

Class 3 - 7

Class 4 - 11

Class 5 - 36

The majority of weeds declared noxious for the Woollahra LGA are not known to be present within the LGA. However, having these weeds listed gives Council as the Local Control Authority immediate regulatory control over any reported occurrence on private land and the ability to respond rapidly with appropriate control measures on Council-managed public land in order to prevent their establishment within the area.

Out of a total of 84 declared noxious weed species within the Woollahra LGA eight are known to be currently present within the area. Of this total three are Class 3 weeds with the remainder being Class 4 weeds.

The Class 3 weeds currently present within the Woollahra LGA are:

	Common name	Scientific name	Image
1	Pampas Grass	Cortaderis selloana
2	Boneseed	Chrysanthemoides monilifera ssp. monilifera
3	Green Cestrum	Cestrum parquii

Photographs courtesy of Sydney Weeds Committees

The Class 4 weeds currently present within the Woollahra LGA are:

	Common name	Scientific name	Image
1	Castor Oil Plant	Ricinus communis
2	Lantana	Lantana camara
3	Asthma Weed	Parietaria judaica
4	Blackberry	Rubus fruticosus
5	Prickly Pear	Opuntia stricta

Photographs courtesy of Sydney Weeds Committees