A splash of innovation: How Sydney Zoo and Sydney Water are working together to reduce water waste – with pumps playing a crucial role.
Sydney Zoo has implemented a comprehensive stormwater capture and recycling system to reduce its reliance on potable water. It involves collecting stormwater runoff and repurposing it for use in moats and garden areas, significantly decreasing drinkable water consumption. By capturing stormwater, the zoo conserves valuable drinking water and mitigates the environmental impact of stormwater runoff.
“We most certainly do have a sustainability focus on water management,” a Sydney Zoo spokesperson said. “All rainwater is captured in the bottom dam, which feeds all the moats throughout the Zoo. With this, we don’t use potable water to top up these moats.”
Suhanti Thirunavukarasu, Sydney Water’s Water Conservation Programs Manager, highlighted the importance of water conservation beyond Sydney Water’s direct influence.
“The interesting thing about the zoo is that they have really taken on board the messages we are sharing with businesses about water conservation and efficiency,” Thirunavukarasu said. “There’s a whole side to water conservation that falls to businesses to step up and use the stormwater they have at their sites. Thanks to this partnership with Sydney Water, we are now able to guide Sydney Zoo through the next steps in their water efficiency programs and complement their stormwater strategy work.”
The zoo’s approach to stormwater management supports its sustainability goals and sets an example for other facilities seeking to optimise their water use. As urban areas continue to grow, finding alternative water sources and improving water conservation efforts become essential in ensuring long-term resource availability.
The role of pumps in stormwater management
The zoo’s stormwater management strategy aligns with broader environmental conservation goals. Effective stormwater harvesting and reuse can alleviate pressure on municipal water supplies, especially during drought or water restrictions.
Implementing such a system requires careful planning and collaboration. Sydney Zoo’s partnership with Sydney Water exemplifies how organisations can work together to achieve environmental objectives.
One of the fundamental aspects of stormwater conservation at Sydney Zoo is ensuring the infrastructure effectively manages fluctuating water levels while maintaining efficiency. Pumps are critical in ensuring stormwater is efficiently captured, stored, and redistributed where needed.
“Even with the Hydraloops that are being trialled across Australia, you need to have a pump to recirculate the water,” Thirunavukarasu said. “It’s a fundamental part of anything where you’re recirculating water because you need to be able to have the pressure to send it back. It’s a key component of these systems.”
Optimising pump efficiency for sustainable operations
Selecting the right pumps is essential to maintaining system efficiency. Pumps must be designed to handle fluctuating demand while operating within an optimal efficiency range.
“When we specify pumps that are used in our system, we look at the system head curves and the different conditions the pumps would have to operate in and come up with a bit of a plan to ensure they’re running efficiently,” Thirunavukarasu said. “We also need to consider energy consumption and heat generation, as these factors directly impact system longevity and operational costs.”
By integrating efficient pumping systems into stormwater management, Sydney Zoo ensures that its water conservation efforts are both practical and sustainable in the long term.
“The main filtration for the shark tank uses a combination of mechanical, biological, and chemical filtration,” a Sydney Zoo spokesperson said. “The life support system combines glass media filters, carbon filters, foam fractionators, and an ozone generator with a contactor unit.
“These filtration processes work together to tackle different aspects of cleaning and clarifying within the large body of water. With the addition of physical cleaning via dive vacuuming, this process can take up to five to six hours at one time to vacuum the gravel, scrub the walls and furniture, and clean the acrylic viewing area so the public can see the sharks and fish.”
Efficient filtration: maintaining water quality
Ensuring high-quality water is essential in environments housing diverse species. Bull sharks require stable salinity, pH levels, and pathogen control to support their health. Their water must be continuously filtered to remove organic matter, maintain oxygenation, and prevent bacterial growth, mimicking their natural estuarine habitats.
Sydney Zoo’s 1.1 million-litre bull shark tank relies on an advanced recycled water system incorporating ultraviolet (UV), ozone, and chemical treatments.
“Sharks require special considerations,” a Sydney Zoo spokesperson said. “Maintaining an entire ecosystem balance is essential for their health and welfare. Bull sharks are Euryhaline, which can adapt to varying salinity levels – fresh, brackish, and marine. We keep the tank at five parts per trillion (ppt), whereas marine is 35 ppt. Salt levels also have therapeutic benefits. Temperature is between 22 and 24 degrees, with pH levels between 6.5 and eight.”
This system ensures the water remains free of harmful bacteria while retaining necessary minerals and salinity. Since 2022, it has saved over 30,000 kilolitres of drinking water, demonstrating how advanced water recycling supports marine conservation and sustainability.
Maintaining water quality through advanced filtration
Thirunavukarasu highlighted the similarities between Sydney Water’s drinking water management and Sydney Zoo’s water quality efforts.
“The way the zoo manages water – monitoring daily, checking chemical levels, disinfecting, and removing pathogens – is quite similar to how we ensure Sydney’s drinking water is safe,” said Thirunavukarasu.
Filtration is key to maintaining a healthy aquatic environment. By implementing advanced technology, Sydney Zoo ensures water quality while reinforcing its commitment to sustainability. To minimise water waste, the zoo captures and recycles 40,000L of vacuum water from the shark tank per dive.
“This water undergoes chlorine treatment and filtration before being safely reintroduced to the system,” a Sydney Zoo spokesperson said. “We still use fresh water to top up what is lost through evaporation and normal system management such as backwashing.”
Energy efficiency: powering sustainable operations
Energy consumption is a critical factor in water management. Sydney Zoo integrates water efficiency with broader sustainability initiatives to minimise its environmental footprint. The zoo spokesperson emphasised how the landscaping supports water conservation across the whole property.
“With all the planting done throughout the zoo, we prevent erosion to ensure we don’t silt up the bottom dam,” they said. “Additionally, with planting through the swale system – a shallow, vegetated channel designed to manage stormwater runoff by slowing, spreading, and infiltrating water – lots of nutrients and impurities are taken out of the water, ensuring the water in the moat system stays healthy.”
Thirunavukarasu focused on Sydney Zoo’s waterside and its work to ensure it makes the most of its precious water resources.
“Sydney Zoo is making the most of every drop they’ve got – that’s recirculating, using alternative water, and improving efficiency in how they manage on-site,” she said. “Even the bathrooms have efficient fixtures and fittings.”
Energy-efficient technologies like variable frequency drives and energy-efficient motors help reduce excess energy use. Smart pump control systems and regular maintenance further optimise energy consumption. By integrating these technologies, Sydney Zoo balances conservation with operational efficiency, demonstrating how targeted infrastructure investments create long-term sustainability benefits.
Collaborative efforts: a blueprint for success
The partnership between Sydney Zoo and Sydney Water is a model for cross-industry collaboration in environmental conservation. Both organisations have achieved significant water savings and operational efficiencies by combining resources and expertise, demonstrating how private enterprises and public utilities can work together towards shared sustainability goals.
“We are excited by this fantastic opportunity to work together,” said Thirunavukarasu. “They’ve got one big tank that they’re already recirculating the water in, and it’s saved something like 30,000 kilolitres over the past couple of years, which is huge.”
This kind of collaboration enables both parties to leverage their strengths – Sydney Water provides expertise in water conservation and efficiency, while Sydney Zoo offers a real-world application where these strategies can be tested and refined. As industries become more conscious of their environmental impact, partnerships like this highlight the benefits of proactive water management.
Engaging with external partners can also provide access to additional resources, such as funding opportunities and technical expertise.
“It’s about more than just water savings; it’s about knowledge-sharing and innovation,” Thirunavukarasu noted. “By working together, we can identify new opportunities to reduce consumption, improve efficiencies, and apply these lessons across different industries.”
This collaboration ensures that sustainability projects can be implemented efficiently and cost-effectively while paving the way for broader adoption of advanced water conservation technologies in commercial and industrial settings.
Looking ahead: Opportunities for broader application
Sydney Zoo’s strategies offer valuable lessons for other industries and institutions. Implementing stormwater capture systems, investing in advanced filtration technologies, and embracing energy-efficient practices can be adapted across various sectors.
These strategies demonstrate the importance of a multi-faceted approach to water conservation, where efficiency, innovation, and collaboration combine to create meaningful and lasting impacts.
Thirunavukarasu pointed out the significance of Sydney Zoo’s efforts as a case study for other organisations.
“The Sydney Zoo example will help create this visibility of what other businesses could be doing,” she said. “They’ve got that unique combination of having the aquarium and the land animals, so looking at that as a case study and seeing how other zoos or other businesses can apply similar strategies is a real opportunity.”
Moreover, these initiatives can lead to cost savings, regulatory compliance, and enhanced community relations. They demonstrate a proactive approach to environmental challenges, positioning organisations as leaders in sustainability.
Beyond the direct financial and operational benefits, these strategies reinforce corporate responsibility, demonstrating a commitment to resource management and ecological preservation.
Thirunavukarasu said Sydney Water and Sydney Zoo’s work will likely influence broader industry trends, encouraging more businesses to re-evaluate their water use.
“Every day, we look at innovative ways we can save water while providing world-class animal care,” said a Sydney Zoo spokesperson. “Sustainability is at the heart of our operations, and we are committed to continuously improving and reducing our water footprint.”
“Water is a finite resource, and every drop counts,” said Thirunavukarasu. “By taking proactive steps today, we can create a more resilient future – not just for businesses, but for the communities and environments that rely on sustainable water management.”
