Search toggle

State of the Science - Catchment Impacts Report

State of the Science - Catchment Impacts Report

What is it?

The State of the Science Catchment Impacts Report is a stocktake of WaterNSW's scientific understanding developed between 2000 and 2009 to guide our management of the catchment.

Based on 10 years of water quality monitoring data, 56 previous scientific and evaluation studies and a range of modelling and risk assessments, the report was the result of more than six months comprehensive work by the WaterNSW science team.

The report was completed in August 2011 and describes our current knowledge about key pollutant groups including sediments, nutrients, pathogens and metals. The report also identifies where knowledge gaps need to be addressed by future scientific research.

Why did we do it?

The State of the Science report was undertaken to see what WaterNSW had learned in our first 10 years of operation.

The key aims of the report were to:

  • critically assess our confidence in the scientific evaluation methods we use and the results they provide
  • identify gaps and issues in the state of our scientific knowledge
  • recommend ongoing research and development priorities.

How was the science collated?

The report assessed the state of scientific knowledge across the organisation based around seven key questions:

  1. How does catchment hydrology influence water quality?
  2. What are the pollutant levels and are they really a problem?
  3. Is water quality changing over time?
  4. What happens during wet weather?
  5. How well do we understand pollutant behaviour and pathways?
  6. Where in the catchment should we be focusing our efforts?
  7. Are our catchment actions effective?

In addressing each of these questions, a scientific - confidence level was applied - insufficient, fair, good or excellent. This highlighted gaps in our knowledge, identifying where WaterNSW needs to focus more resources.

What did we learn?

Some key findings included:

  • WaterNSW has a good conceptual understanding of pollutant behaviours and pollutant sources within the catchments
  • Our routine water monitoring program provides a sound and representative dataset for the assessment of water quality against guideline values
  • Twelve of the 19 inflow catchments assessed did not pose any significant water quality risks, except during very high flows
  • Communication of information on catchment pollutants and/or high flow events can be improved
  • Wet weather monitoring at catchment sites could be improved.

Read the report at the bottom of this page - State of the Science Catchment Impacts Summary Report (August 2011).

What are we doing now?

In response to the findings of the State of the Catchments report, we are undertaking a range of activities that will help us to better manage our catchments.

These include:

  • Installing new wet weather monitoring stations
  • Developing a wet weather risk assessment tool
  • Conducting a gully erosion trial
  • Developing a grazing evaluation model
  • Conducting a Sewage Treatment Plant evaluation trial. 
Wednesday 25 April
1,894,256 ML
2,581,749 ML
11,883 ML
1,698 ML
-13,815 ML
Wednesday 25 April