Takaka Hill Site C2, Nelson

Client : Fulton Hogan and NZ Transport Agency Waka Kotahi
Scope of Works : Horizontal Drain Install

Ground Anchor Systems was engaged by Fulton Hogan and NZTA to install the horizontal drainage across multiple sites on Takaka Hill following the major storm event in 2025. With significant ground movement and elevated groundwater pressures, deep dewatering was essential to stabilise the slope and keep the highway open.

Using our Casagrande C6 XP2 rig, we’ve been drilling drains up to 70 metres through complex ground conditions, requiring temporary casing and adapted drilling techniques to maintain progress. To date, more than 1,700 metres of drains have been installed across two sites, with works expected to wrap up in mid‑April.

Early results have been extremely positive. Continuous flows from the arrays and monitoring of nearby piezometers show a clear drop in groundwater levels.

Takaka Hill is the only route over the range, relied on daily by locals, freight operators, and visitors. It's a privilege to contribute our expertise to a project that underpins that reliability.