Where Rock Meets Root: Slope Stabilisation at Coolum Horizons

The Project

The Coolum Horizons development, located in the prestigious Sunshine Coast region, was designed to transform a challenging parcel of land into a premium residential estate. The project required the creation of stable foundations for future housing, reliable access routes, and the integration of natural aesthetics into the landscape. With a focus on long-term durability and visual appeal, the project team sought innovative solutions to overcome the site’s complex terrain and environmental constraints.

The Challenges

The site presented several engineering and environmental challenges. A significant variation in elevation across the area made ground stabilisation a priority. Compounding this was the presence of weathered rock, which made it extremely difficult for vegetation to take hold. The original plan involved extensive rock pitching to manage erosion and slope stability, but this approach lacked the desired natural appearance and was not conducive to supporting plant growth. The client needed a solution that would not only stabilize the steep 1:1 batter but also allow for successful revegetation to blend the development into its natural surroundings.

The Solution

After consulting with Global Synthetics, a trial concept was developed to test a more sustainable and visually appealing alternative. The solution involved placing 200-300mm of topsoil over the batter, followed by the installation of a modified ARMORMAX® High Performance Turf Reinforcement System. This system typically includes PYRAMAT® 75 Turf Reinforcement Mats, percussion earth anchors, and retaining pins. However, due to the underlying weathered rock, a custom anchoring method was adopted using Dynabolts to penetrate the topsoil and secure the system into the rock layer beneath.

The trial area proved highly successful, demonstrating both structural stability and the ability to support vegetation. As a result, the solution was scaled up tenfold to cover the majority of the site. Since implementation, vegetation has become well established, delivering the natural aesthetic the client envisioned while ensuring long-term erosion control and slope stability.

Global Synthetics is proud to have supported J Dale Fisher Architects and Sunshine Coast Civil in delivering a sustainable, visually integrated solution for the Coolum Horizons project. Our tailored approach and innovative use of geosynthetics helped transform a difficult site into a thriving, build-ready landscape.

Client: J Dale Fisher Architects

Contractor: Sunshine Coast Civil

Subcontractor: Dream Landscapes

Location: Coolum Horizons Estate, QLD

Product: Modified ARMORMAX® High

Performance Turf Reinforcement System

Quantity: 6,000m2