Auckland's underground infrastructure is a complex network of tunnels and pipes that support the city's water supply, wastewater management, and transportation. Key components include the Central Interceptor, a major wastewater tunnel project, and the City Rail Link, a new underground railway line.
The Central Interceptor is a 14.7-kilometer tunnel designed to reduce wastewater overflows into Auckland's harbors. As of 2026, it is under construction and expected to be completed by 2028. The City Rail Link, a 3.45-kilometer twin-tunnel underground railway, is set to open in 2026, connecting Britomart to Mount Eden.
Other underground assets include water supply tunnels, such as the Western Springs tunnel, and stormwater systems. These networks are managed by Auckland Council and Watercare Services Limited. The infrastructure is critical for the city's growth and resilience against climate change.
