We want Sydney Harbour to be a place where people can relax, swim and enjoy the water safely.
Creating a swimmable harbour is a key idea in Sustainable Sydney 2030–2050 Continuing the Vision. Cleaner water can support more swimming and recreation opportunities in the harbour, while respecting the deep cultural connection First Nations people have to these waters.
When sites meet national recreational water quality guidelines, more safe swimming locations may become possible.
Improving water quality brings clear benefits. It protects the environment, supports physical and mental wellbeing, strengthens the local economy and reduces the need to build new swimming pools and facilities.
But achieving this outcome, particularly in the City of Sydney local area, is complex and will take sustained, long-term effort.
What needs to change to enable safe swimming
To make inner-city harbour swimming safer, key actions include:
- reducing stormwater pollution through green infrastructure, such as biofiltration
- continued investment in wastewater and stormwater infrastructure by the responsible agencies
- improving water quality monitoring and understanding of pollution sources
- upgrading supporting parkland and public access infrastructure where appropriate.
What the research tells us about harbour swimming
Our research highlights several challenges for swimming in the City of Sydney area.
- Water quality is harder to manage due to historical industrial land use and sediment contamination, dense urban development, stormwater runoff, old sewer systems and heavy boat traffic.
- Water quality often gets worse after rain where bacteria levels can remain elevated for several days, depending on the site’s flushing characteristics. Unlike open ocean beaches where pollution disperses in a few days, harbour sites flush at very different rates. Enclosed areas recover more slowly after rain or pollution, leading to less reliable water quality.
- Bacteria can also rise during dry weather, likely caused by leaking sewer connections or pollution from boats.
Addressing these issues is essential to safely open more of Sydney Harbour for swimming in the future.
Assessing potential swim sites
Before any site can be opened for public swimming, it must meet the National Health and Medical Research Council (NHMRC) guidelines for managing risks in recreational water.
This involves:
- assessing nearby pollution risks (sanitary inspection category)
- carrying out extensive water quality testing (typically 100 samples over at least 12 months)
- evaluating how quickly contaminants disperse at each location.
These requirements ensure public health is protected and swimming sites are safe and reliable.
The NHMRC guidelines use a multiple-barrier risk assessment, combining microbial water quality, sanitary inspection and site characteristics, rather than relying on a single water quality result.
Potential swimming locations in Sydney Harbour
We assessed these locations for their swimming suitability, based on water quality testing, access and surrounding conditions.
Site-by-site research findings
Each location was assessed against a range of criteria including water quality, sanitary risks, access, marine activity and surrounding infrastructure. The factors below summarise the primary considerations for each site.
- Farm Cove (Royal Botanic Garden) is not supported for public swimming due to environmental, operational and management considerations.
- Pirrama Park has elevated bacteria levels that don’t currently meet national recreational water quality guidelines. Water quality is also affected by its enclosed harbour setting and relatively slow contaminant flushing.
- Darling Harbour does not currently meet national recreational water quality guidelines. High levels of urban stormwater runoff, limited tidal flushing and its enclosed location contribute to poorer water quality.
- Dawes Point was not progressed for detailed water quality assessment because of intensive commercial and recreational vessel traffic.
- Blackwattle Bay presents challenges due to historical sediment contamination and relatively slow contaminant flushing.
- Elizabeth Bay (Beare Park) was assessed as having a very high sanitary risk due to its proximity to sewer infrastructure and sewer overflow points, and its position as a natural low point where stormwater and potential overflows can accumulate. Water quality monitoring at Beare Park recorded enterococci levels of up to 2,900 CFU/100 mL. The 95th percentile for the assessment period was 2,611 CFU/100 mL, placing the site well above the highest microbial assessment category in the current NHMRC guidelines.
Overall, most sites we assessed face significant and ongoing water quality risks.
How local water quality compares to other harbour swim sites
The map below summarises water quality at selected harbour locations using the 95th percentile of enterococci (CFU/100 mL). Data for established harbour swim sites was sourced from the NSW Beachwatch monitoring program, while data for sites not routinely monitored by Beachwatch, including Pirrama Park and Elizabeth Bay, was collected by Sydney Water and the City of Sydney.
For comparison, sites with a 95th percentile of enterococci above 200 CFU/100 mL have elevated microbial contamination. Under the NHMRC guidelines, microbial assessment is based on 4 categories: A (≤40), B (41–200), C (201–500) and D (>500 CFU/100 mL). The microbial assessment is considered together with the site’s sanitary risk to determine the overall level of risk.
The assessment shows that established harbour swim sites generally fall within the low or moderate categories, while the investigated sites within the City of Sydney local area recorded high microbial contamination during the assessment period. These findings, together with the known sanitary risks associated with ageing sewer infrastructure, nearby sewer overflows and pumping stations, indicate that significant improvements would be required before new public swim sites could be considered.
Next steps
We’ll continue working with key stakeholders to identify and reduce sources of contamination across the harbour.
Improving harbour water quality is a long-term effort, but each step brings Sydney closer to a cleaner, more accessible waterfront for everyone.
