Through its network of State Associations, the National Stormwater Industry Association (Stormwater Australia) has members in all Australian states and territories. Individual state associations are generally incorporated bodies under local jurisdictions with a committee of management that guide activities of importance to the individual States.

Membership

State associations promote the sharing of knowledge and ideas through a program of seminars, state conferences and awards events.

Increasing advocacy and the building of strategic partnerships is seen as an important role for state associations and the network umbrella provided by Stormwater Australia allows states to share ideas around these important activities.

	Stormwater New South Wales  (SIA NSW) Stormwater NSW links the diverse and multi-disciplinary interests of the Stormwater Industry in NSW and the ACT and represents them at the state level.
	Stormwater Queensland (SIA QLD) Stormwater Queensland is an incorporated not for profit association that seeks to facilitate effective stormwater management by providing leadership, representation and services to its members and the wider stormwater industry.
	Stormwater South Australia (SIA SA) Stormwater South Australia's mission is to assist in the development of a sustainable stormwater industry for the greater benefit of its members and the broader public.
	Stormwater Victoria (SIA Vic) Representing mainly Victorian practitioners, Stormwater Victoria is active in running seminars, annual excellence awards, an annual tour and AGM. Currently, Stormwater Victoria accepts Tasmanian members while the interest in stormwater management in that state grows.
	Stormwater Western Australia (SIA WA) SIAWA is a non-profit Industry association that promotes sustainable urban water management through the management of stormwater. It draws its membership from local government, product suppliers, engineering professionals and the wider consulting industry.