Stormwater Pollution
Stormwater runoff from roofs, roads, paved areas, building sites and parks can pick up many pollutants, including litter, organic material, nutrients, oils and grease, suspended solids, pathogens, metals, pesticides and other chemicals.
Pollution is a threat to ecological health and our use and enjoyment of bays and waterways.
Pollution in Blackwattle Bay
In 2003, the City modeled stormwater pollution in the Blackwattle Bay catchment (which drains to the Sydney Fish Market). The results are summarised below:
Stormwater pollution in Blackwattle Bay
Source: Ecological Engineering Pty Ltd
This inflow of pollutants has a significant impact on receiving water and sediment quality in Blackwattle Bay. In fact research by Dr Gavin Birch (University of Sydney) found sediments in Blackwattle Bay are amongst the most polluted in the world.
Observed concentrations of copper, lead and zinc would almost certainly have a significant impact on ecosystem health in the bay.
Sediment contamination decreases with distance from stormwater canals in Blackwattle and Rozelle Bays. Bed-load and stormwater in these canals are also contaminated suggesting the pollution sources are land based, particularly roads.
To read the detailed research on Blackwattle Bay stormwater impacts click here.
Harbourwatch
While water quality of Sydney Harbour has generally improved in recent times it continues to be degraded by pollution from stormwater, sewer overflows, land contamination and vessels.
Results for various harbour sites monitored by Harbourwatch often show Darling Harbour to be the most polluted of the Sydney Harbour sites monitored. 2006–2007 was no exception, with Darling Harbour regularly having elevated faecal coliform and enterococci levels.
Faecal coliform levels at Darling Harbour frequently exceed guidelines for primary contact. Compliance with the guidelines have ranged between 23% and 59% during the past five years. Over the same period, enterococci compliance has varied between 32% and 74%.
Enterococci levels in Darling Harbour
Source: NSW Department of Environment and Climate Change
Faecal coliform levels in Darling Harbour
Source: NSW Department of Environment and Climate Change
Streamwatch
The Streamwatch program, run by Sydney Water, involves schools and community groups to monitor water quality. Streamwatch sites around the City of Sydney LGA include:
- Federal Park Wetland and Johnson’s Creek
- Blackwattle Bay
- Sydney Park
- Jones Bay
- Royal Botanic Gardens
- Woolloomooloo Bay
- Centennial Park and Moore Park
Results are available on the website www.streamwatch.org.au
Federal Park wetland
Streamwatch results for Federal Park wetland show that issues of concern for the wetland are oxygen levels, turbidity, phosphorus and bacteria.
Blackwattle Bay
The other significant Streamwatch site within the City of Sydney LGA is Blackwattle Bay which is monitored by the Sydney Institute TAFE. Research results show that issues of concern in Blackwattle Bay are turbidity and bacteria.
Environmental Indicators
Water quality testing is also conducted by Sydney Water. The Environmental Indicators Monitoring program measures pH, temperature, dissolved oxygen, turbidity, nutrients and bacteria.
Within the City of Sydney LGA, monitoring takes place at Blackwattle Bay and Rushcutters Bay. Monitoring shows higher pollution levels in wet weather which is attributed to stormwater and sewer discharges.
Downloads
- Macrophytes in Sydney Harbour | PDF 420Kb
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Last Updated: Monday 27 April, 2009
