Step 1
Hazard Assessment
We assess the slope, failure mechanism, rockfall trajectory, and risk to infrastructure or persons. For emergency response, assessment happens on the day of mobilisation — our engineers are on-site within days of an event.
Solutions
Geohazard Engineering
Emergency slope response, rockfall mitigation, difficult access, and landslide stabilisation.
GEOHAZARD ENGINEERING
New Zealand's terrain makes geohazard risk unavoidable. Steep, fractured hill country from Northland to Fiordland is cut by river valleys, coastal cliffs, and mountain passes — terrain shaped by tectonic activity, high rainfall, and ongoing seismic loading that keeps slopes in a state of dynamic equilibrium. When that equilibrium breaks — through an earthquake, a prolonged rain event, or the progressive weathering of a rock face — the consequences for roads, rail, buildings, and people can be severe. Effective geohazard engineering requires the capability to respond fast, assess accurately, and build permanent solutions on ground that often resists conventional access.
GSI NZ's Geohazard Engineering division responds to and permanently repairs the full spectrum of slope and rockfall hazards — from emergency stabilisation within days of a failure event through to engineered long-term solutions that restore full serviceability. We work across transport infrastructure, rail corridors, mining environments, and residential sites throughout New Zealand. Our geotechnical engineers have direct experience on New Zealand's most significant geohazard events (the 2016 Kaikōura earthquake, which generated hundreds of slope failures across the SH1 corridor, and Cyclone Gabrielle in 2023, which required simultaneous emergency response across nine State Highway sites in Hawke's Bay).
WHY GSI NZ
WHERE OTHERS CAN'T GO,
WE WORK.
- —01NO HANDOFFS, NO GAPSThe engineers who assess the hazard are the same people who direct the crews that fix it — one integrated design-build team from first site visit to final sign-off, with full QA documentation on completion.
- —02ACCESS NOBODY ELSE HASHelicopter-deployable drill rigs and IRATA Level 3 rope access crews reach near-vertical cliff faces, remote alpine slopes, and terrain accessible only by air — with rockfall barriers rated to 8,000 kJ for the highest-energy sites.
- —03NZ Transport Agency Waka Kotahi PRE-QUALIFIEDPre-qualified for State Highway geotechnical and slope works, SiteWise Gold accredited, and Totika Listed, with 24/7 emergency readiness backed by direct experience across post-earthquake and Cyclone Gabrielle multi-site response.
HOW WE APPROACH GEOHAZARD ENGINEERING
Step 2
Solution Design
Our in-house geotechnical engineers design the permanent solution (soil nails, rock anchors, rockfall barriers, mesh, drainage, or a combination) matched to the specific hazard, site access constraints, and programme.
Step 3
Design/Build Delivery
Our crews carry out the works under engineering supervision, using our purpose-built equipment fleet and IRATA rope access capability. Full QA documentation and as-built records are provided on completion.
GEOHAZARD ENGINEERING SERVICES
Rockfall Mitigation
Rock bolting, meshing, scaling, and energy-absorbing barriers, from assessment to permanent protection.
Difficult Access Solutions
IRATA rope access and helicopter-deployable equipment for steep, remote, or cliff sites where conventional access is impossible.
Landslide & Slope Stabilisation
Limit equilibrium analysis, soil nails, rock anchors, and drainage for permanent landslide repair across New Zealand.
Rockfall Scaling
Manual, mechanical and remote scaling by IRATA-certified technicians, providing source removal as the foundation of every mitigation programme.
Rockfall Containment & Control
Barriers, drape mesh and attenuator fences, passive containment systems rated to 8,000 kJ and sized to site-specific trajectory modelling.
Rail Geohazard Mitigation
Slope stabilisation, embankment repair and rockfall protection for New Zealand's rail corridors, with minimal track disruption.
Mining Geohazard Services
Open cut and underground geohazard solutions for New Zealand's mining and quarry sector, with rapid response when operations are at risk.
Riparian Bluff Stabilisation
Stabilising eroding riverbank bluffs and coastal margins, protecting roads, bridges, farmland and infrastructure nationwide.
CAPABILITY
Capability nobody else has
GSI NZ is pre-qualified with NZ Transport Agency Waka Kotahi for State Highway geotechnical and slope works, enabling rapid engagement on emergency contracts without procurement delays. We have direct experience managing post-earthquake response — including the Kaikōura 2016 earthquake — and multi-site emergency repair programmes such as the Cyclone Gabrielle recovery across nine State Highway sites in Hawke's Bay. Every response is managed by an integrated design-build team: the engineers who assess the hazard are the same people who direct the crews that fix it.
Our IRATA-certified crews hold Level 1 through Level 3 certification, qualified to work independently, supervise teams, and conduct live rescues. Combined with specialist rockfall technician and geotechnical qualifications, our rope access crews carry out full engineering works from positions that no platform or elevated work platform can reach. Where the terrain demands helicopter deployment, our lightweight drill rigs can be positioned on the face to install rock anchors, soil nails, or investigation boreholes — giving us geohazard capability on slopes where no other New Zealand contractor can operate.
Difficult Access Solutions →FREQUENTLY ASKED QUESTIONS
RELATED PROJECTS
GEOHAZARD ENGINEERING
DOME VALLEY SH1
118 rock anchors and 790 m² TECCO mesh installed by helicopter and rope access.
View Project →GEOHAZARD ENGINEERING
EPITAPH HAAST SH6
Rockfall mitigation on one of New Zealand's most challenging remote highway corridors.
View Project →GEOHAZARD ENGINEERING
OHAU POINT
Rockfall containment and control on a high-risk coastal SH1 corridor.
View Project →Get in Touch
Geohazard on
Your Site?
Our in-house geotechnical engineers have responded to thousands of geohazard events across New Zealand. Call us and we'll assess your site fast.
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