Peter Walker & Partners
American Architecture Prize 2017 | 2015 Australian Institute of Landscape Architects (AILA) Presidents Choice Award (NSW) | Infrastructure Partnerships Australia Project of the Year (2016) | WAN Waterfront 2015 Award.
At the heart of one of the worlds industrial capitals, we grew trees. Barangaroo holds an extremely important place in the story of Sydney, with a rich history and close ties to the natural world. The reserve was developed to recreate a headland that existed prior to European arrival. With complete restoration in mind, Barangaroo Reserve was developed using almost completely recycled resources.
Take a look at how this project came to be...
The development of the reserve was created upon the land of a former colonial shipyard. By retracing the original shoreline, plans begun to restore this land to its former grandeur.
SESL was brought on to develop a soil profile that most accurately resembled the pre-industrial soil conditions. This was to ensure the most efficient native plant rehabilitation. The research performed by the BDA and its contractors resulted in two published scientific papers on the nutrition of native plants. This allowed the headland project to become not just an aesthetic reconstruction, but gave us the knowledge of how to restore and rebuild a vegetation type that is part of the character of Sydney and its' harbour.
Researching the land
We then did some field research in areas of intact sandstone flora looking at the natural “Kandosol” or “Yellow Earth” soil characteristic of sandstone country. We examined the profile and measured the levels of nutrients and general soil chemistry. In a series of pot trials, we calculated and determined different levels of green waste compost to be applied to the various sensitive locations (5% in sandstone areas, 10% in Eucalypt and forest areas, 20% for recreational).
After the soil profile concept, and our nutrient calibrations were completed, SESL worked on the sandstone terrace cross sections. An early diagram of the sandstone terrace facsimile illustrates how this was done so contractors tendering on the project could see how it was to be constructed.
The soil landscape at Barangaroo was carefully worked to support a vegetation type with unique requirements for healthy growth using almost 100% recycled resources sourced from in and around Sydney.
Resources were recycled from:
Crushed sandstone originating from building excavations in Barangaroo South commercial developments.
Recycled sand and crushed glass sand from building excavations.
Recycled green garden waste compost (produced from “green bin” and council drop off garden waste collections).
Composted wood mulch screened from green garden waste collections.
These commonly available recycled resources could be used to make
The mulch layer or “O” (for organic) horizon analogous to the forest litter layer.
The topsoil or A horizon, a well drained sandy soil containing nutrients, organic matter and biological life.
The Subsoil or B horizon, a well drained water holding layer for root anchorage and moisture reserve.
The reserve opened in 2015 and has since continued to flourish. The planting has achieved a phenomenal rate of success. SESL understood that Sydney's native sandstone belt thrived in what could be perceived as extremely poor soils. Thanks to this, the Barangaroo reserve project proudly achieved a 99% plant retention success rate.