Landscape Architect Articles

Water Re-Use Project, Sydney Park, Australia03-21-17 | Feature

Water Re-Use Project, Sydney Park, Australia
In an effort to future proof the city, Sydney endorsed and is implementing the Decentralized Water Master Plan as part of Sustainable Sydney 2030.

Landscape Architecture by Turf Design Studio & Environmental Partnership

A bifurcated Corten steel viaduct delivers water into bioretention ponds to be cleaned and released into the Guwali Wetland. The water scheme diverts on average each year some 221 million gallons of stormwater for treatment and reuse. The treatment train includes a gross pollutant trap, 5,000 square meters of bioretention systems, wetlands and the existing ponds. Untreated stormwater from the 494-acre upstream catchment previously flowed into the Munni Channel, then into the Alexandra Canal and into the ocean at Botany Bay.
*Photo: Simon Wood*

The "Millennium Drought' of the late 1990s and early 2000s brought to Australia its worst period of drought on record. Unwillingly, Sydney had to draw upon remote river catchments to maintain its water supply until the drought was declared officially over in 2012.

In an effort to future proof the city, Sydney endorsed and is implementing the Decentralized Water Master Plan (2012-2030) as part of Sustainable Sydney 2030. The plan is focused on reducing water mains consumption and demand through a number of approaches: rain gardens, vegetated systems, stormwater recycling and trigeneration plants.

Water filtered from the bioretention ponds drains into the wetland lagoons via terracotta half-pipe viaducts. Turpin + Crawford Studio worked with TDEP and Alluvium to conceive the design, which echos the site's industrial and brickworks heritage. Birds like to perch on the half-pipes.

The Sydney Park Water Re-Use Project, built in partnership with the Australian government through the National Urban Water and Desalination Plan, is part of this comprehensive water strategy and is Sydney's largest environmental project to date. With climate change predictions of more irregular rainfall patterns in southeastern Australia, the project demonstrates an integrated approach to prepare the city for the decades ahead and looks within its catchment to provide the needed water supplies for the city.

Turpin + Crawford's water falls installation, "The Cascades', celebrates the passage of water along the water treatment "train" back into the Wirrambi Wetland. The Cascades provide critical aeration of the stored waters.
*Photo: Ethan Rohloff Photography*

Sydney seized a once in a lifetime opportunity to use what was essentially an infrastructure project as a vehicle to breathe new life into the park and make it a vibrant recreation and environmental asset. The landscape architects of Turf Design Studio & Environmental Partnership led the design team and orchestrated a multidisciplinary collaboration that interwove design, art, science and ecology. The resulting "roundtable' facilitated a shared design dialogue between water experts Alluvium, artists Turpin + Crawford Studio, ecologists Dragonfly Environmental, engineers Partridge and the city's own landscape architects. The skilled landscape contractors from Design Landscapes were responsible for implementing this complex project on the ground. The result is as combination of water reusage, recreation and habitat that gives life to its water story, and an exciting new dimension to this well-loved parkland.

Turpin + Crawford Studio's "Waterfalls' delivers water flows through cantilevered terracotta half-pipe fingers.
*Photo: Ethan Rohloff*

The city and the design team recognized that a fully integrated collaborative design environment was required to fully realize the opportunities presented by the project and the site.

The project had three key objectives:
Water Management: Effectively harvest urban wastewater, improve water quality and reduce potable water consumption.

Landscape and Habitat: Strengthen the visual and functional connections between the park's water bodies; improve the landscape setting, recreational opportunities, environmental amenities and habitat value.

Interpretation: Uncover and express the park's water story through design and artful influences within the landscape, including immersive opportunities for interactive play and education.

Much has been achieved over the past two decades in transforming the Sydney Park site from its industrial and landfill legacy into 44 hectares of parkland. The park is just 7.5 km south southwest from the iconic Sydney Harbour Bridge.
*Photo: Ethan Rohloff Photography*

The Outcome
Much has been achieved over the past two decades in transforming the Sydney Park site from its industrial and landfill legacy into 44 hectares of parkland that are a vital asset for the growing communities of south- east Sydney.

The project now provides enhanced circulation of water through a chain of ponds and wetlands; improving water quality, visual amenity and detention storage effectiveness. The water scheme diverts on average each year 840 megaliters (221 million gallons) of stormwater for treatment and reuse. The treatment train includes a gross pollutant trap, 5,000 square meters of bioretention system, wetlands and the existing ponds.

Children traverse the bioretention wetlands on stepping-stones. Editor's note: Can't help imagining the little girl just about to touch down will slip and fall back, smacking her head on the stone from whence she hopped.
*Bottom photo: Photo: Sara Reilly; Top photo: Adam Hunter*

Previously, all stormwater from the 200-hectare (494 acres) upstream catchment flowed through to Munni Channel, and into Alexandra Canal and Botany Bay untreated. (Historical note: On April 29, 1770, Captain James Cook and his HMS Endeavour crew made their first Australian landfall at what they dubbed "Botany Bay." The bay is about 8 miles south of the Sydney business district.) The ponds at Sydney Park suffered poor water quality and outbreaks of blue-green algae and Azolla. Azolla (aks mosquito or duckweed fern, and fairy moss) is a pernicious genus (Salviniaceae) of aquatic ferns that can stagnate waterways in periods of low rainfall and during the warmer months.

In conveying the water story through its visible processes the project is educating the community about the importance of urban water management and the interdependent nature of our urban and natural environments. Turpin + Crawford's "Water Falls' installation celebrates the passage of water from the end of the water treatment "train" and back into the system at Wirrambi Wetland, while supplementing "The Cascades" in providing critical aeration of the stored waters.

Turpin + Crawford Studio also worked with TDEP and Alluvium to conceive the water "exhaust fans" that celebrate the transfer of water from bioremediation "paddies" to the lagoons. These play on the spirit of water and its interactions with topography, form, surfaces, plant life and fauna. The fans only function for two to three hours after heavy rainfall, reflecting that the bioremediation beds are at capacity.

Buffer shrubs on wetland embankments provide habitat and screen gabion retaining walls. Existing aquatic plants were retained and replaced as necessary. Eucalypt woodlands extend into the wetland to shade the path. Tree plantings took advantage of new soil reserves west of the wetland.
*Photo: Ethan Rohloff Photography*

After an intensive period of easing in the Water Re-Use Project is now fully operational and intrinsically merged within the park setting. The park's fauna and flora is thriving, with new habitats created and existing ones protected and enhanced throughout the park.

This project has made a significant contribution to the realization of the Sustainable Sydney 2030 targets for local water capture and reuse, and promises the opportunity to significantly expand reuse through the reticulation of recycled water to local industry.