Water quality data

River health is determined by the quality of the water. In order to maintain the ecological processes that support native fish populations, vegetation, wetlands and birdlife, we need high water quality. The water quality is measured using three indicators; chemical, physical and biological. These indicators are affected by pollution and environmental change.

A summary of historical trends of some water quality indicators are provided below. This data has been collected by numerous government agencies such as Sydney Catchment Authority, Department of Primary Industries and by the community in the Hawkesbury-Nepean Catchment. It is a useful tool in understanding how the catchments water quality has changed over time.