Water quality is an important aspect of river health. We sample water at over 100 monitoring sites to assess how water quality is changing over time – you can download yearly summary results on this page.
Indicators of water quality
We test water samples for the following range of indicators, which tell us about overall water quality:
- water temperature
- dissolved oxygen
- salinity - salt levels
- pH level - acidity or alkalinity
- nutrients - forms of nitrogen and phosphorus
- faecal contamination - E. coli
- metals - arsenic, cadmium, chromium, copper, lead, nickel and zinc
In summer, we also test key recreational sites weekly for E. coli and blue-green algae. Excessive amounts of these can cause skin irritation or illnesses for people and pets that come into contact with the river.
How we use water quality data
We use our data to assess how water quality is changing over time – typically over an eight to ten year period. This gives us enough measurements to detect significant changes, from which we can then find the causes and take action.
We also share our findings with the Environment Protection Authority and Department of Environment, Land, Water and Planning, who set policies and objectives for improving river health, and audits any changes to our monitoring network:
Our data is used to develop the Yarra and Bay Report Card where trends over time can be seen for each catchment, site and indicator. You can also see how each catchment and site complies with State-wide objectives.
The data is available to download from the Department of Environment, Land, Water and Planning - Water Measurement Information System.