Broad scale diffuse source water pollution patterns

The NSW Diffuse Source Water Pollution Strategy identifies sediments, nutrients and pathogens as priority diffuse source water pollution problems to be addressed across NSW.

The Australian Agricultural Assessment 2001, conducted as part of the National Land and Water Resources Audit 2001, reports on landscape processes, soil, nutrient and water movement. This resource can be used by land managers to gain a broad scale picture of sediment and nutrient movement in the landscape and provide a 'first-pass' in identifying areas where diffuse source water pollution problems may exist.

For example, budgets of average total nutrient loads have been estimated for each major region and for each river basin in Australia. This includes sediment-bound total phosphorus and total nitrogen budgets (t/yr) for hill slope, gully, and river bank erosion and run-off estimates of dissolved phosphorus and dissolved nitrogen (t/yr). Estimates of average annual total phosphorus and total nitrogen export by river network are also provided. Further information can be found at: http://www.anra.gov.au/topics/agriculture/pubs/national/agriculture_nutrient_loads.html.

An assessment of water-borne erosion and sediment transport for Australia's agricultural catchments and rivers can be found at:
http://www.anra.gov.au/topics/agriculture/pubs/national/agriculture_soil_erosion.html. This report provides broad scale predictions of sheetwash, rill (hillslope), gully and riverbank erosion, including identifying gully and riverbank erosion as the dominant sources of sediment supplied to streams in southern Australia. Suspended sediment loads presented as the mean annual suspended sediment yield per hectare of catchment is also provided.

The full report can be found at: http://www.anra.gov.au/topics/agriculture/pubs/national/agriculture_contents.html.

Page last updated: 26 February 2011