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Water quality at Lake Parramatta

City of Parramatta manages a comprehensive water quality program to monitor the environmental status of Lake Parramatta and advise users about any change in conditions.

The City of Parramatta's Water Quality Program includes:

  • Microbiological (enterococci bacteria) monitoring - samples are regularly collected from different locations within the lake, including in the sectioned off swimming area. Bacterial levels are monitored and compared with levels described in the National Health and Medical Research Council Recreational Water Guidelines.
  • Water temperature – this is measured around the lake, including a temperature vs. depth measurement in the designated swimming area. 

Results, alerts or notifications are reported regularly on this website.

Other water quality parameters measured include pH, phosphorus, nitrogen, turbidity and conductivity. Heavy rain can cause microbial contamination of water by organisms such as bacteria, viruses and algae. NSW Health recommends that you do not swim within 24 hours of heavy rain at ocean beaches and within 3 days in estuaries or rivers.

The guidelines also state that the temperature of water should be between 16oC and 34oC for safe swimming. A wetsuit would be recommended for any water temperatures below 16oC.

Water Quality Monitoring locations

This map shows seven locations at Lake Parramatta where water quality sampling occurs (LP2a and LP2b are located within the swimming area).

Water Temperature and Bacteria Results


Annual Average Enterococci Levels

Indicator LP1 LP2a LP2b LP3 LP5
Enterococci (bacteria) cfu/100ml 29 100 36 33 36

Enterococci levels of less than 200 cfu/100ml would generally be regarded as being suitable for swimming.

How you can help

City of Parramatta encourages the local community to improve and care for the water in Lake Parramatta. Sydney's stormwater drains carry water to an extensive network of streams, wetland, ponds and lakes, including Lake Parramatta. They provide habitat for fish, frogs and birds while improving the liveability of the city.

What can you do to prevent pollutants from entering the waterways?

  • wash your car on the grass. Do not let the soap enter the drains or use a water-recycling car wash facility. Phosphates from detergents encourage algal growth
  • do not flush chemicals or paint into stormwater drains. This means fresher water for fish, birds, frogs and everyone else
  • prevent leaves and grass clippings from washing down the drain. Use smaller amounts of fertilisers and garden chemicals
  • put rubbish in bins, paper and plastics in the recycling and do not throw cigarette butts in the gutter 
  • clean up after your dog. Animal waste promotes harmful bacteria in the water
  • compost garden waste and use it to improve garden soil. Green waste when released into the waterways results in algal blooms.

These simple measures will help keep Lake Parramatta beautiful and clean for everyone to enjoy.