Tunnel Engineering

Tunnel technology Solutions Tunnel types Sector Tunnels Local & Global expertise Projects WSP Experts

WSP is a trusted leader in tunnel planning, design, rehabilitation, and construction across Aotearoa New Zealand. We bring together all required disciplines—engineering, geotechnical, fire and risk, ventilation, and asset management—under one roof to deliver safe, resilient underground infrastructure.

The Value of Tunnels in Aotearoa’s Infrastructure

Tunnels are essential to modern infrastructure across Aotearoa New Zealand. They connect communities, reduce travel time, and support safe, efficient transport networks. Water and wastewater tunnels enable reliable sanitation and hygiene, while utility tunnels carry electricity, telecommunications, internet, and gas—powering everyday life.

Underground spaces also support transit systems, energy storage, and scientific research. Delivering these complex assets requires a wide range of engineering expertise. At WSP, we combine local knowledge with global experience to design and construct innovative, resilient, and safe tunnel solutions beneath our cities, landscapes, and waterways.

Technology-Driven Tunnel Design

At WSP, we use advanced technologies to deliver smarter, safer tunnel infrastructure across Aotearoa. Our design teams apply tools like numerical modelling for ground-structure interaction, Building Information Modelling (BIM) and Virtual Design and Construction (VDC), to refine tunnel schematics in a virtual environment. This allows us to identify and resolve potential issues before construction begins—reducing delays, unexpected costs, and risks to surrounding structures.

With deep expertise across rail, roads, and aviation, we understand tunnels from every angle. Our holistic approach ensures tunnel design and construction is efficient, resilient, and tailored to the needs of New Zealand’s infrastructure networks.

The Waterview Connection is the largest and most complex road infrastructure project ever undertaken in New Zealand. A 14.4m outside diameter Earth Pressure Balanced (EPB) Tunnel Boring Machine (TBM) was used to complete the twin 2.4km long tunnels, located at the heart of the scheme.

Exploring AI Impact on Tunnel Design

WSP engineers discuss various subsets of artificial intelligence, their application and industry impact.

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Comprehensive Tunnel Solutions for New Zealand Infrastructure

Delivering safe, resilient tunnel infrastructure requires more than construction expertise. It demands a holistic approach that integrates planning, design, and systems thinking from day one.

End-to-End Tunnel Delivery

From early feasibility and consenting, through to construction, long-term asset management, and maintenance, we combine local expertise and leverage global best practice to provide end-to-end expertise across the tunnel lifecycle.

Delivering Complex Tunnel Projects

Tunnel projects are often large, complex, and high-risk—making a Systems Engineering approach essential for successful delivery. We provide project support to mitigate risks and ensure tunnel infrastructure is safe, resilient, and fit for purpose.

Proven Success in NZ and Beyond

WSP is proud to support the City Rail Link in Auckland—New Zealand’s largest infrastructure project—where, as a member of the Link Alliance, we provide Requirements Management and Systems Integration services.

Our Comprehensive Tunnelling Expertise Covers Every Stage of the Tunnel Lifecycle:

Rock and Soft Ground Tunneling for diverse geological conditions

Specialist Design and Materials Engineering for durability and safety

Tunnel Mechanical and Electrical (M&E) Systems integration

Foundation and Excavation Support/Retention Systems Design

Drill and Blast techniques for complex environments

Digital Engineering and Advisory for optimized delivery

Understanding and Controlling Ground Water to protect structural integrity

Tunnel Survey, Geometry, and Visualization for precision planning

Construction Programming for timely, cost-effective outcomes

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Tunnels for Every Sector

Roading

We understand that tomorrow’s road tunnels must do more than serve today’s needs. Our approach focuses on future-ready tunnel design, blending traditional transportation with driverless vehicle integration, multi-service functionality, and advanced safety systems. By planning for reliability, improved safety, and evolving ownership models, we create tunnels that support next-generation mobility and deliver long-term value.

Energy and Resources

We partner with energy and resources clients to deliver customised tunnelling solutions that enhance operational efficiency. Our designs focus on maximising direct operating hours, improving system reliability, and reducing maintenance costs through innovative operational design strategies. By integrating advanced tunnelling techniques, we help clients achieve long-term performance and resilience in critical infrastructure projects.

Rail and Transit

We bring deep knowledge of the business and economic drivers behind successful rail and mass transit projects involving major tunnels. Our team ensures every design, planning, and delivery phase aligns with operational requirements and key success factors, creating tunnelling solutions that optimise performance, reliability, and long-term value for transit networks.

Underground Spaces

As urban populations continue to rise, governments are turning to underground space to free up valuable land for development. These spaces demand complex tunnel networks and large-span caverns to support storage, transport, and infrastructure needs. With proven expertise in designing caverns exceeding 20 meters in span, we lead the way in delivering innovative underground solutions that power the storage revolution and future-ready urban planning.

Utilities

With extensive experience in cable tunnel projects, as well as electricity and water utilities, hydropower, dams, reservoirs, bulk conveyance systems, and drainage and sewerage networks, we deliver end-to-end tunneling solutions. Our approach integrates specialist design, durability-focused engineering, and lifecycle planning to ensure long-term performance and reliability for critical infrastructure.

Pedestrian Tunnels

To enhance urban connectivity and improve safety, we design pedestrian tunnels that provide secure, weather-protected pathways beneath busy roads and transport corridors. Our solutions prioritise user experience, incorporating lighting, ventilation, and accessibility features while leveraging advanced materials engineering and digital design tools to deliver durable, low-maintenance infrastructure for growing cities.

Local Expertise Backed by Global Collaboration

Our dedicated Systems Engineers in Aotearoa New Zealand work alongside more than 30 specialists in Australia and a global team of 65+ experts in the UK. This strong local presence, backed by international best practice, allows us to deliver tunnel solutions that meet the highest standards across transport, water, and utility networks.

We apply Systems Engineering techniques from the earliest stages of a project—covering feasibility, requirements management, integration, and long-term maintenance. This approach reduces rework, improves coordination, and delivers significant cost and schedule benefits over the project lifecycle.

Related projects

Auckland, New Zealand

City Rail Link

City Rail Link (CRL) is the largest and most complex transport infrastructure project ever undertaken in Aotearoa New Zealand. As part of Link Alliance, WSP has worked with City Rail Link Ltd and Link Alliance members to help deliver a twin-tunnel underground rail link through central Auckland, including new stations at Te Waihorotiu and Karanga-a-Hape and a redeveloped Maungawhau station. The project will transform how people move through Tāmaki Makaurau, increasing rail capacity, improving access to the city centre and wider region, and enabling faster, more frequent and better-connected journeys.

Southland, New Zealand

Homer Tunnel

The most challenging engineering projects are often the most satisfying. Just ask the team who worked on Homer Tunnel’s brand-new avalanche shelter. Building in a World Heritage and National Park between avalanche seasons was no mean feat – made more impressive by having to deal with unpredictable weather and a tight construction timeframe.

Sydney, Australia

Sydney Metro

Delivering an astonishing feat of engineering to open mobility, opportunities and connections for a city.

Hong Kong

Mitigating Geotechnical Risks for Deepest, Longest, and Largest Sub-Sea Road Tunnel Ever Built in Hong Kong

Construction to alleviate traffic congestion and shorten journeys. This is the deepest, longest, and largest sub-sea road tunnel ever built in Hong Kong.

Singapore

Supporting Safe Construction of a Road Tunnel to Ease Traffic Congestion

The 1.3 km Sentosa Gateway Tunnel is a two-lane, one-way road tunnel connecting outbound traffic from Sentosa Island directly to major roads to alleviate congestion.

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Istanbul, Turkey

Eurasia Tunnel (Istanbul Strait Road Tube Crossing)

First road tunnel construction across the Bosphorus linking Europe and Asia: innovation and international collaboration to solve technical challenges.

Washington, DC, USA

First Street Tunnel

During a storm event, the First Street Tunnel will store up to 30.3 million liters of combined sewer overflow in its 853 meters of tunnel and 4 shafts, preventing flooding in Bloomingdale and Le Droit Park.

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Missouri, USA

Lower Meramec Tunnel Project

The 6.8-mile-long tunnel project — the largest ever for Metropolitan St. Louis Sewer District (MSD) — will improve water quality within the Meramec River watershed and help ensure regulatory compliance.

Norfolk to Portsmouth - Virginia - US

Elizabeth River Tunnels

The first deep-water concrete immersed-tube tunnel in North America will significantly reduce travel time while greatly improving safety.

Antioquia, Colombia

Toyo Tunnel

WSP contributed its experience to the largest tunnel project in America part of the megaproject of 18 tunnels, 30 bridges and 17 kilometers of open-air roads in Colombia.

Portland, Oregon, USA

East Side and West Side CSO Tunnels

The complex and highly successful combined sewer overflow (CSO) tunnel projects were key infrastructure components of the City of Portland, Oregon’s efforts to improve the water quality of the Willamette River.