Mangawhai Heads Volunteer Lifeguard Service (MHVLS) Slope Stabilisation

The February 2023 Cyclone Gabrielle weather event triggered a significant slope failure immediately above the Mangawhai Heads Volunteer Lifeguard Service (MHVLS) clubhouse, sending hundreds of cubic metres of rock, soil, and vegetation down the hillside, impacting the two-storey clubhouse below and resulting in its closure.

LDE was engaged as geotechnical design consultant on the repair, working within a design and build contract alongside Earth Stability, and subject to a rigorous programme of independent peer review throughout.

The site's volcanic geology made this a genuinely complex problem. Our team mapped the slope and surrounding geomorphology and identified and characterised the rockfall hazards at different elevations, built a geotechnical ground model, and ran iterative slope stability and rockfall analyses to inform a specific engineered design which was reinforced and informed by targeted laboratory testing to provide accurate soil and rock parameters to optimise design outcomes. The result was a hybrid stabilisation system, combining active rock bolts and mesh in the highest-risk zones with rock anchors and soil nails elsewhere. The design was refined throughout construction as further colluvium and talus were uncovered.

The project began appropriately, with a hui and blessing alongside iwi and the club, recognising the site's cultural significance before any ground was disturbed. LDE supervised construction, carried out anchor pull testing, and adapted the design as conditions evolved.

With the slope secured, repairs and refurbishment of the clubhouse were completed, and the much-loved community facility reopened its doors in May 2026.

You can read more about the reopening here.