General

Stormwater is defined as the run-off from rainfall events; it collects pollutants from across a wide area and transfers them to receiving waters. Sources in urban areas include domestic, commercial and industrial premises, road surfaces, parks and gardens and stormwater run-off typically contains litter, sediments, oils and grease, heavy metals, nutrients, bacteria, pathogens, pesticides and other contaminants. Sources in rural areas are mainly associated with land clearing and agricultural activities (livestock grazing, irrigated and dry land cropping, intensive livestock industries), with forestry and unsealed rural roads; stormwater run-off can contain elevated levels of sediments, nutrients, pesticides, acids and other chemicals. The recent government focus on urban stormwater has resulted in improved management. Councils are implementing stormwater management plans on a catchment basis and controls on new development are in place; gross pollutant traps, litter booms, trash racks and detention basins are being included within the drainage system where appropriate and are resulting in improved environmental outcomes. A trend towards more integrated water cycle management is emerging involving stormwater capture and recycling and re-use of water and wastewater and some councils are focusing on non-structural stormwater management as part of the more integrated approach. A state-wide stormwater education program is also underway.

Key Issues

There are several main issues that need to be addressed in stormwater management. In urban areas impervious surfaces, which greatly increase water flows and the potential for soil erosion, need to be replaced with pervious surfaces and in both urban and rural areas pollution needs to be addressed at source. Efficient landuse practices are crucial for mitigating stormwater impacts. The use of stormwater as a resource needs to be explored further and widely promoted. Run-off from acid sulfate soils is a critical issue for estuaries and coastal waters.

Protocols

Monitoring of stormwater discharges is important to determine the efficacy of stormwater treatment devices and to assist in critically assessing potential impacts on human health and aquatic ecosystems. The National Water Quality Management Strategy has a guideline relating to stormwater management and a number of others that relate to management of rural industries: effluent management guidelines for: dairy sheds; dairy processing plants; intensive piggeries; wineries and distilleries; aqueous wool scouring and carbonising; and tanning and related industries.

For methods for the analysis of water pollutants consult the EPA (1998) reference: Approved methods for the sampling and analysis of water pollutants in New South Wales. The methods are based on the American Public Health Association, USEPA standard methods and the Standards Association of Australia.

Core protocols are those for the following indicators:

Aquatic ecosystem health
Industrial areas
Physical and chemical
Urban stormwater

Supplementary protocols / information relate to:

Amphibian monitoring
Bacteria monitoring
Catchment combing
Constructed wetland monitoring
Desktop monitoring using satellite data
Diatom monitoring
Ecotoxicology
Environmental flows
Fish monitoring for water quality
Gross pollutant trap monitoring
Landfill
Load monitoring
Macroinvertebrate monitoring
Metals in sediments
Metals in water
Oil and other spills
On-site sewage monitoring
Pesticides and herbicides
Protozoan monitoring
Riparian vegetation monitoring
Salinity
Saltmarsh
Seagrass
Streamwatch

Contacts - Core Agencies

The main organisations with formal responsibilities include the following.

• The EPA (now within the Department of Environment and Conservation) under the Protection of the Environment Administration Act 1991 required councils to prepare stormwater management plans and agencies to prepare stormwater environmental improvement programs on a catchment basis. The EPA assisted councils with funding through their Stormwater Trust and also funded Extension Officers. These officers worked through regionally-based groups of Councils; they sought to enhance partnerships with local government, facilitate commitment and build the capacity of local government to manage stormwater based on their needs, priorities and resources.
• Councils are responsible for management of stormwater and diffuse source pollution in urban areas while pollution in run-off from rural areas is essentially the responsibility of individual landholders (within the limits of the POEO Act). Rural councils assist land managers and promote programs that address rural run-off such as phosphorous action plans. Roadside management plants and soil erosion control plans.

Other organisations involved

• The SCA (Sydney Catchment Authority) has assisted rural councils within its areas of operation with implementation of their SMPs and SCA and NSW Agriculture are assisting the dairy industry to better manage waste and minimise run-off
• SWC (Sydney Water Corporation) has considerable stormwater assets to manage and also assists councils in the development and implementation of the SMPs
• NSWAgriculture and DIPNR are providing financial assistance, extension and educational services in rural areas in relation to diffuse source pollution in general and the management of acid sulfate soils in coastal areas.
• Landcare community groups are addressing urban and rural stormwater run-off by rehabilitating riparian areas and preventing land degradation

Case Studies