Highway 22 Landslip Remediation Program

MaCC provided geotechnical and civil engineering services for a series of landslip remediation projects along State Highway 22 near Glen Murray. Slope movement had resulted in shoulder loss, pavement damage and reduced stability along sections of the road corridor.

Working with Waikato District Council, we undertook geotechnical investigations and engineering assessments to identify the causes of the failures and develop practical, long-term remediation solutions. The programme included retaining structures, road and shoulder reconstruction, drainage improvements, erosion protection and construction phase support.

The project sites were located within steep terrain where natural erosion, groundwater seepage and prolonged wet weather had contributed to progressive instability. Several locations required resilient engineering solutions to restore slope stability while maintaining a safe and reliable transport route.

A key site involved a major landslip where an existing retaining structure had been compromised by ongoing ground movement. Following detailed geotechnical assessment, MaCC worked closely with Waikato District Council to develop a retaining solution using the EcoReef modular retaining wall system. The works restored support to the road corridor while incorporating improved drainage, road shoulder reconstruction, erosion protection, revegetation and upgraded roadside safety barriers.

The EcoReef system provided a durable and sustainable alternative to conventional retaining structures. Its modular design enabled efficient construction within a constrained site, reduced material requirements and construction impacts, and supported improved drainage and vegetation establishment. The result is a resilient, lower-impact solution that delivers long-term infrastructure performance while reducing the environmental footprint of the project.