General

Agricultural water is that used for irrigation, livestock drinking water and general on-farm use. It is derived from groundwater and from the surface waters of rivers and streams. Increasingly in some areas wastewater may be used for irrigation purposes. Agriculture is the dominant land use in NSW. The availability of water for irrigation through river regulation and the increased use of groundwater have provided new opportunities for agriculture over the last few years. Irrigation accounted for 90% of the surface water used in NSW in 1996-97 and 64% of groundwater was used for irrigation, 20% for other rural uses and 16% for urban/industrial purposes. There has been a 76% increase in total water use for irrigation between 1983/84 and 1996/97 and groundwater use has increased by 217% over the same period. Groundwater resources are being used beyond sustainable yield in many areas. Many waterways have poor water quality with salinity and nutrient loads increasing. Blue-green algal blooms continue across much of the State. In some urban and peri-urban areas recycled wastewater is now used for landscape watering and irrigation of pasture and certain crops.

Key Issues

The decreasing quality of both surface and groundwater is the key issue for agriculturalists. In some areas salinity in groundwater renders it unsuitable for consumption or irrigation, and rising salinity, turbidity and contaminants in surface waters are of concern. Most inland rivers have concentrations of phosphorous that could support excessive growth of algae; there are potential health risks for both humans and livestock from toxicants from blue-green algae. Sediments, nutrients, toxic chemicals (hydrocarbons, trace metals, pesticides and herbicides) are entering waterways from both point and diffuse sources and poor land management practices and reduced river flows exacerbate problems. Water used for irrigation interacts with the physical and chemical characteristics of the soil and the tolerance of different crop species to toxic substances varies. Toxicity problems can arise if contaminants accumulate to concentrations high enough to cause crop damage resulting in lower yields or reduced crop quality.

Protocols

The ANZECC and ARMCANZ guidelines (2000) for agricultural water focus on algae, human and animal pathogens, plant pathogens, pH, major ions (bicarbonate, chloride, sodium), salinity and sodicity, heavy metals and metalloids, nutrients (N, P), pesticides and radiological quality.

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:
Physical and chemical
Pesticides and herbicides
Chlorophyll a
Algal blooms
Diatom monitoring

Supplementary protocols / information include those relating to:
Acid sulphate soils
Algal species density and diversity
Amphibian monitoring
Constructed wetland monitoring
Desktop monitoring using satellite data
Environmental Flows
Fish kills
Fish monitoring for water quality
Groundwater
Load monitoring
Macroinvertebrate monitoring
Primary productivity
Profiling
Real time Chlorophyll monitoring
Riparian vegetation monitoring
Salinity
Streamwatch

Contacts - Core Agencies

• Department of Infrastructure, Planning and Natural Resources (DIPNR) manages the planning and sharing of water across the State and administers water management licences issued under the Water Act 1912 for surface and ground water extractions. Undertakes continuous surface water monitoring (600 stations), key sites monitoring and groundwater monitoring (ca 2000 bores). Maintains databases on the condition of the State’s land, soil, water and vegetation
• NSW Agriculture provides best management practice guidelines and practical advice on farm production and associated environmental issues to commercial farmers, graziers, horticulturalists and agribusinesses. They regulate agricultural chemical use under the Pesticides Act 1999 and Fertilizers Act 1985 and have legislative responsibilities also in regard to pests and noxious weeds, stock and plant diseases.
• Department of Environment and Conservation (DEC (NSW), incorporating the former EPA, regulates, provides advice and implements guidelines on the use of reclaimed water and of biosolids, and on chemical storage and use. Department of Infrastructure, Planning and Natural Resources (DIPNR)

Other organisations involved

• NSW Recycled Water Coordination Committee set the quality criteria for reclaimed water.
• NSW Health monitors water quality test results and is advised by the water supply authority of reclaimed water schemes commissioned and of any treatment breakdown or malfunction.

Case Studies