The Department of Planning and Environment, in collaboration with local councils, monitors water quality and ecosystem health in estuaries across New South Wales. The results of this monitoring program are used to generate report cards, which enable us to compare water quality and ecosystem health over time.
State-wide water quality monitoring in NSW estuaries is carried out as part of the NSW Marine Estate Management Strategy.
Water quality report cards
We monitor water quality in estuaries across NSW by measuring ecosystem health indicators including:
- abundance of algae
- water clarity
- a range of supporting indicators, such as salinity, oxygen, pH, temperature and suspended sediments.
These indicators tell us about the health of ecosystem processes and how the water quality might support and enhance biodiversity and habitats for each estuary.
Our Estuaries and Catchments Team develop estuary water quality report cards based on the 2 main water quality indicators: algal abundance and water clarity.
The data from our monitoring program is used to develop guideline values for relevant water quality indicators following principles outlined in the National Water Quality Management Framework. Reference systems with pristine catchments and minimal disturbance for type of estuary are sampled routinely to develop guideline values. Monitoring data is compared to the guideline values to determine the condition of an estuary over time.
A full description of how grades are calculated is available in our technical report Assessing estuary ecosystem health: Sampling, data analysis and reporting protocols.
The estuary water quality data that supports the development of the report card grades is available on our SEED data portal. This assessment does not measure human-use environmental issues such as drinking water quality, safety for swimming, heavy metal contamination, disease, bacteria, viruses, or ability to harvest shellfish or fish.
What the grades mean
A healthy estuary has clear water and low levels of algal growth. Each water quality report card gives an overall grade for the health of an estuary for a specific year based on combined measurements of water clarity and algal abundance.
The grades range from A (excellent health) to
E (very poor health):
- A – excellent
- B – good
- C – fair
- D – poor
- E – very poor.