Building a complex stormwater harvesting plant on one of the world's busiest beaches was in many ways a gamble for Waverley Council in New South Wales.
However, it was one that paid dividends for the environment, the local community and more recently the council's trophy cabinet.
The council came away from the 2015 Keep Australia Beautiful Clean Beach Awards, held in Darwin in August, with the National Environmental Sustainability Award for Bondi Beach, largely thanks to its Bondi Stormwater Scheme.
Constructed in 2012, the $1 million Bondi Stormwater Scheme harvests and re-uses stormwater previously discharged into the ocean at the southern end of Bondi Beach.
The scheme was built to process 50 million litres of stormwater per year, which is then used for irrigation, toilets and public cleaning at Bondi Beach.
A Waverley Council spokesman said the scheme was designed to make use of the reliable stormwater flow travelling down the Bondi catchment that would otherwise go straight out to sea, carrying with it pollution from streets, homes and businesses.
“That way we’re conserving water, saving money and improving water quality at Bondi Beach,” he said.
The spokesman said the project team had navigated a number of challenges during construction, not least of all the strict deadline.
"We had to work to a tight four-month timeline because all major works had to be completed and the site reinstated by mid-December, to allow full public access during the busy summer period," he said.
"The soil in the park behind the beach is very sandy, which was very difficult to keep stable when making deep excavations for the construction of underground infrastructure.
"Plus we had to work on a site which hosted a maze of underground services, including a network of international submarine fibre optic cables.
"Needless to say, you have to tread pretty carefully around obstacles like that – especially when you’re driving an augur bore right alongside them!"
How the Bondi Stormwater Scheme works
The main off-take for the Bondi stormwater scheme is from a large Sydney Water Corporation (SWC) junction pit that is situated at the southern end of the park and receives water from the 115 hectare Bondi South catchment.
Water flows into this junction pit after passing through SWC gross pollutant traps.
It is then conveyed via a single trunk drain for discharge at the southern shoreline of Bondi Beach
The Bondi stormwater scheme draws water at the rate of two litres a second from this source.
The system also handles polluted stormwater run-off from Campbell Pde, the heavily trafficked, crowd-thronged tourist strip which runs the length of Bondi Beach. For this run-off, it uses Hydrocon porous pipe filtration technology to remove heavy metals, hydrocarbons and phosphorous.
The harvesting system uses grinder pumps to harvest water which is then subjected to 100 micron backwash filtration and UV treatment.
A 10 kW photovoltaic solar system, which is installed on the roof of Bondi Pavilion, provides energy for the carbon neutral operation of the scheme.
The main design features
Hydrocon pipe filter: Porous pipe technology treats stormwater run-off from Campbell Parade by removing sediment, heavy metals, hydrocarbons and phosphorus.
Stormwater harvesting: Stormwater is diverted via gravity into a deep pit with grinder pumps which macerate pollutants and transfer water for treatment
Filtration and disinfection: Filtration and UV treatment of harvested water to remove fine particles and pathogens
Storage tank: 300 kilolitre underground storage tank - roughly the size of 4 average swimming pools
Excess filtered water: Excess filtered stormwater is discharged at South Bondi
Other award winning beaches at the 2015 Keep Australia Beautiful Clean Beach Awards
Keep Australia Beautiful, Australian Clean Beaches winner 2015: Guilderton, Western Australia
Runner Up: Burleigh Beach, Queensland
Community Action and Wellbeing: Port Julia, South Australia
Dame Phyllis Frost Litter Prevention, Waste Management and Resource Recovery: Richardsons Beach, Tasmania
Heritage and Culture: Garig Gunak Barlu National Park, Northern Territory
Young Legends: Burleigh Beach Queensland
Environmental Education: Guilderton, Western Australia