Mersey Point Sea Wall
City of Rockingham
Overview
In 2021/22, Westpeak Engineering assisted the City of Rockingham in the construction of a 380m long seawall to protect a vulnerable section of coastline in Shoalwater. The project was undertaken in two stages and over the course of approximately 22 weeks. Westpeak Engineering acted as the Superintendent for the works, which were completed by Neo Civil. Design of the seawall was completed by Advisian.
The construction works involved:
- Replacing an existing degraded seawall.
- Earthworks, temporary coffer dam protection and dewatering.
- Construction of a new seawall, including geotextile, underlayer and armour rock.
- Design and construction of a set of piled beach access stairs.
- Various landscaping works.
Project Highlights
The works were successfully completed on time and within budget and were well received by the City. Management plans and construction processes were closely monitored and enforced to ensure that all requirements for the works were met and that disruption was minimised for the many stakeholders involved.
The constructed seawall has performed well and provided protection against erosion to the important infrastructure and properties along this section of coastline.
The project was awarded the Best Public Works Project under $2 Million award at the Institute of Public Works Engineering Australasia's (IPWEA) Excellence Awards.
Project Challenges
- Exposed section of coastline and varying metocean conditions, including periods of significant wind and waves.
- The Stage 1 portion of the seawall included work within Heritage Place 22891 (Mersey Point Burial) and a vegetated area that required clearing.
- The works were immediately adjacent to a busy road and residential area.
- The access and laydown areas were very limited and in particular for the Stage 1 works.
Project Solutions
- A number of actions were taken during the course of the project, including wetting down areas, mobilising street sweepers and relocating sand stockpiles, to minimise wind blown sand during windy periods. The coffer dam was also strengthened as a precaution ahead of a storm event and expected large swells.
- The Cultural Heritage Management Plan for the works was strictly enforced. This included 4 Traditional Owners and an archaeologist being present on site during all ground disturbing works. Westpeak also worked with Neo and the City to minimise the extent of clearing required to construct the works.
- A detailed and two phased Traffic Management Plan was implemented to provide safe detour and access for rock and sand deliveries throughout the works. Nearby residents were also regularly updated, and all queries were resolved in a timely manner.
- Westpeak Engineering worked closely with the City and the Contractor to ensure a successfully delivered project.
