Australian Gardens a Study in Urban Innovation

Modern materials take a surprising turn in these 'ancient ruins' of Sydney.
10 March, 2017
In the eastern part of greater Sydney, the old Paddington Reservoir site has seen new life as an urban park.
When Australian architectural partners TZG and JMD were asked to take on the project, most people thought they'd simply cap off the century-old underground site and build a green space on top of it. No one envisioned what ultimately became an award-winning park the city describes as "a blend of the ancient Baths of Caracalla in Rome and the Hanging Gardens of Babylon," right in a dense urban environment.

The reservoir, originally constructed in 1866 and 1878, held water chambers below street level with – during the 1930s – a grassy park above it. In 1990, nearly a century after the facility had stopped functioning as a reservoir, the roof collapsed on what had by then become an old garage workshop.
Instead of thinking about ways to fill in the derelict hole, the architects envisioned sunken gardens that relied on the history of the site itself, and offered dramatic spaces using the remnant walls and vaults. They decided to salvage as much of the historic brick, cast iron and timber of the original construction to protect the original architectural expression. They then limited new materials to just three – steel, aluminium and concrete – to deliver their contemporary vision of the public sunken gardens.

Lightweight aluminium roofs float above the street-level entrance points, with mesh designs that extend the historic brick archways that serve as the garden's foundations. The lightness of the roofs acts as a counterpoint to the solid earthiness of the masonry vaults, the architects explain, while there is a whimsical reference to the older masonry mortar joints in the staggered pattern of the metal grid.
At night, the lighting along the length of the aluminium arches creates a feathered effect, with a soft glow from beneath its wings as visitors enter through an original archway. It's also how the simple lawn on the eastern roof is connected seamlessly with the sunken western portion, which is accessible by stairwell or an alternate elevator, and signals a welcome at an entrance that might otherwise appear similar to a subway train station or parking facility.

Yet the garden below is visible from Oxford Street, where low walls protect sidewalk passers-by. When they choose to descend from the street into the sunken garden, the first thing they'll notice is that not all of the historic roof collapsed. There are surviving islands of the roof that serve as rooftop gardens, supported by the original brick arches. Guinea flower vines spill over the edges, above unique sections of restored construction with the colonnade look of ancient Rome or Athens.
Beneath them, visitors gather near a sheltered pond for a quick lunch in the city oasis, or with more time wander pathways that were built using a raised pre-cast concrete boardwalk around the perimeter and stepping stones within. In one section of the restored reservoir, the architects preserved graffiti art that was on the underground walls – a legacy of the garden that's beneath the street level eastern portion.

As for the garden, the reservoir has its own unique microclimate, with sun and shade that supports subtropical species and some rainforest plantings. The site also returns, in a way, to its own water storage heritage: the rainwater runoff is collected from both levels and stored beneath the boardwalks for irrigation use.
Banner image: Wikimedia