Environmental issues

Water quality

Sediment and nutrient hotspots in the Murray-Darling Basin

In 2005 the former Murray-Darling Basin Commission (MDBC), National Land and Water Resources Audit, and CSIRO Land and Water completed a study to assist in identifying important sediment and nutrient sources to rivers of the Murray-Darling Basin.

The project is described in detail in the report: Sediments and nutrients in the rivers of the Murray-Darling Basin - Targeting the future.

The study provides a broad overview of the distribution of sources of sediment and nutrient loads in the rivers of the Murray-Darling Basin. It found that most sediment and nutrients are generated and transported from the upland catchments in the eastern and northern parts of the basin but sources of sediment vary across the Basin. Hillslope erosion dominates in the north, while gully and river bank erosion dominate in the upland areas of NSW and Victoria.

A product of the study included a series of maps identifying erosion source hotspots as well as sediment delivery efficiency. A supporting CSIRO report: Patterns of Erosion and Sediment and Nutrient Transport in the Murray-Darling Basin (tr32-03.pdf; 4466KB) also provides estimates of sediment loads on a sub-catchment basis.

The study concluded that management actions considering both erosion source and sediment delivery efficiency will be most cost-effective.

It should be noted that the results of this study are aimed at informing management decisions at the catchment or whole-of-basin scale. There is potential, however, to enhance the information so that it is relevant at a regional level, if more detailed, higher resolution data is available.

Page last updated: 26 February 2011