It is important for the well-being of the valley to keep an eye on the health of Wolli Creek, including its water quality, the state of the banks and its flora and fauna.

Our small teams of volunteers now regularly sample water quality at locations in the Bardwell or Wolli Valleys and report their results to Sydney Water’s website. Training and test equipment are provided through Sydney Water’s Streamwatch Program

You might see us on the riverbank with our bottles and pole dipping into the water to collect a sample.

Teams would welcome additional people along to use their skills or learn new ones. If you are interested in joining us, write to or ring 9554 3176.

What’s in Wolli Creek and Bardwell Creek?

River water, stormwater runoff, rainwater and also tidal seawater in the lower reaches of Wolli Creek

Fish, worms, mussels, crabs, microorganisms

Aquatic plants and algae

Sediments on the river bed that may contain heavy metals like lead, zinc and arsenic.

And after heavy rain or sewer chokes … sewage from sewerage overflows

What does Streamwatch test and why do we test it?

The temperature of the water has a major effect on biological activity and growth of river organisms.

pH tells us how acidic or alkaline the water is. Freshwater fish and other river life are sensitive to changes in pH. Extremely high or low pH levels will lead to the death of aquatic life.

Electrical conductivity tells us how much salt and organic acid is in the water. Freshwater organisms cannot live in very salty water.

Turbidity tells us how cloudy or muddy the water is. Turbid water reduces the amount of light entering the river environment. Plant growth decreases and this impacts on the animals that rely on the plants [for food, shelter, oxygen].

Dissolved oxygen is essential for fish, worms, etc living in the river. Fish die if there is not enough dissolved oxygen in the water and they get environmentally ‘stressed’ if the levels are low. This means they are more susceptible to disease, etc.

The available phosphate test tells us how much soluble phosphate there is available to plants in the water. Phosphorus in phosphates is a nutrient essential to the growth of plants and animals. Too much phosphate leads to an abundance of algae and aquatic weeds and less oxygen for fish.

Faecal coliforms are naturally occurring bacteria found in the intestines of all warm blooded animals including humans. If we find faecal coliforms in the river it generally means the river has been contaminated by human sewage.

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