Hornsby Quarry
Parkland
Hornsby Council
Completion Due 2025
Sydney, Australia
Since being decommissioned in 2003, Hornsby Quarry has remained mostly untouched. However, with the help of SESL and other industry partners, Hornsby Council are designing the complete conversion of this abandoned site into a new park for the community. The former Quarry will form the parks centre, with the eventual establishment of a green corridor along the quarries edge.
SESL were engaged as soil specialists to provide consultation on the design advice, and develop soil concept and specifications for the project. This project presents itself with an array of unique challenges including heavy slope conditions, varying soil suitability and endemic vegetation types...but our team love a good challenge!
Read about what we've been up to so far.
02
Vegetation Communities
With plans to rehabilitate large areas with native species on a site with a heavy industrial past, it was important to fully understand the soil conditions. The available materials (Tunnel spoil and mining overburden) typically present with an alkaline pH, differing from the more acidic profile the native plant communities would grow on (Blackbutt Gully Forest and Blue Gum Diatreme Forest).
We assisted Hornsby Council in designing soil specifications, recommended amelioration, and soil generation procedures to optimise revegetation. SESL designed specifications from the available site materials, tunnel spoil and overburden with great consideration to the soil chemistry requirements for endemic species.
04
Future Works
SESL continues to work on this project in the construction phase, providing consultation and quality control analysis. We are currently consulting with the bulk earthworks and topsoiling team at the quarry.
When unveiled, Hornsby Park will be a truly amazing feat, covering approximately 60 hectares of bushland and open space, featuring a ‘Canopy Skywalk’, walking tracks, active and passive recreation spaces and water-based recreation opportunities. Due to the background and involvement in the design phase, SESL has assisted in the synergy between client and contractor through consultation to achieve sound, practical and effective soil management on site for a landmark project.
01
Harsh Conditions
When we first visited the Quarry, what was immediately evident were the unique site conditions. The soil landscapes were unique, involving two soils of recovered nature. Majority of the site to be revegetated is old mining overburden, originally pulled from the quarry to allow for extraction of basalt. Slopes within the development footprint were also extreme in some areas, creating a challenge for soil rehabilitation.
03
Conducting Trials
For the extremely steep slope conditions, SESL designed soil profiles or ‘buildups’ to provide suitable growing conditions. Using the soil formulations and buildups designed by SESL, Hornsby Council set up a comprehensive trial to assess the relationship of the plant and soil.
The trial plots included controls, compost additions and fertiliser applications as variables to observe how the selected species interact with the proposed soil mixes, and if any deficiencies or stunting occurs from their use.
