Bondi Beach is one of Australia’s most heavily visited coastal environments and a focal point for Waverley Council’s long‑running program to improve water quality, harvest stormwater for reuse and harden assets against marine exposure. Council’s published material confirms the Bondi Stormwater Harvesting Scheme and ongoing upgrades to treatment devices and trunk infrastructure to protect the beach from polluted runoff along Campbell Parade and the wider catchment.
Within this broader program, the Bondi Beach storm‑water outlet required a durable, low‑permeability concrete solution suited to chloride‑rich marine exposure while maintaining whole‑of‑life value for ratepayers. Boral supplied ENVISIA® Low Carbon Concrete to meet the durability and sustainability aims of the project.
Project Challenge
The outlet sits in an aggressive marine splash and spray zone. In such conditions, the dominant durability threat for reinforced concrete is chloride ingress, which depassivates steel and accelerates corrosion, undermining service life and driving costly repairs. Contemporary literature and guidance highlight that controlling permeability and chloride transport is central to long‑life coastal assets.
The design team also sought to reconcile performance, constructability and cost. Stainless reinforcing is often specified for such environments; however, it carries a substantial premium. The challenge was to achieve the required design life and corrosion performance without unnecessary materials inflation for a publicly funded asset.
Boral Solution
Boral proposed ENVISIA® Low Carbon Concrete for the outlet works. ENVISIA® is engineered for low permeability to limit chloride ingress, supporting corrosion resistance of reinforcement and reducing maintenance risk in coastal infrastructure applications. By pairing ENVISIA® with appropriate cover, curing and detailing, the solution addressed durability limit states that typically drive lifecycle costs in marine projects.
Durability Consultant, Jonathan Dyson from BCRC, said "the original specification called for stainless steel reinforcing, but ENVISIA®'s excellent resistance to chloride ingress allowed the use of standard mild steel reinforcing with no reduction to the design life. This was a significant cost saving for the client."
Team Engagement
Boral collaborated with Waverley Council and the BCRC durability team to align concrete performance parameters with the project’s exposure classification, cover requirements and construction windows at Bondi. Close coordination ensured supply and placement practices were tuned to a high‑salt, high‑spray environment and to Council’s operating constraints in a busy public beachfront setting.
Project Outcomes
The storm‑water outlet renewal aligns with Waverley’s broader program to reduce pollution loads, improve beach water quality and conserve potable water through harvesting and treatment. Council reports the Bondi scheme treats significant runoff from Campbell Parade and supplies non‑potable uses across the foreshore, contributing to both environmental outcomes and operational savings.
From a materials perspective, specifying ENVISIA® delivered a durable, lower‑carbon concrete solution for a chloride‑prone coastal asset, while the validated substitution to mild steel reinforcement provided a cost‑efficient structure with the required design life. The approach reflects best practice for performance‑based durability design, where permeability control and exposure‑appropriate detailing can enable smarter whole‑of‑life decisions.
Conclusion
The Bondi Beach storm‑water outlet demonstrates how Boral’s ENVISIA® can underpin durable, sustainable and cost‑effective outcomes in marine infrastructure. In an environment where chloride ingress typically dictates reinforcement selection and lifecycle cost, the project team leveraged a low‑permeability, lower‑carbon concrete to achieve the required design life without resorting to stainless steel, freeing public funds for other community priorities.
