Work is well underway beneath the streets of Newmarket and Grafton on a major stormwater upgrade that will help protect Hobson Bay and improve the water quality of nearby beaches for years to come.
The Lower Khyber Pass and Kingdon Street Stormwater Separation projects are part of Auckland Council and Watercare’s Eastern Isthmus Water Quality Programme; a joint initiative focused on reducing wet-weather wastewater overflows into local waterways and the Waitematā Harbour.
While much of the work is out of sight, its impact will be far-reaching. By physically separating stormwater from wastewater, the project will stop rainwater overwhelming the wastewater network during heavy downpours, one of the main causes of overflows that can carry contaminants into streams, the harbour and ultimately our beaches.
Construction began in February 2025 and is expected to be completed in late 2026. With a combined investment of $17.5 million, the two closely linked projects provide the backbone infrastructure needed to support growth in one of Auckland’s busiest and most constrained urban catchments.
The works are tackling several long-standing issues in the area, including ageing and undersized pipes, partially combined wastewater and stormwater systems, frequent overflows affecting nearby business areas, and repeated flooding around the rail corridor.
Deputy Mayor Desley Simpson says the project is a real win for Aucklanders and for the city’s future.
“By using smart, innovative construction methods, we’ve saved around $2 million on delivering cleaner beaches, healthier waterways and the stronger infrastructure our growing city depends on.”
Underground, the scale of the work is significant. The project includes deep stormwater shafts near the University of Auckland and Kingdon Street, new stormwater connections from surrounding streets and manholes, and major upgrades to pipes along Kingdon Street, Lower Khyber Pass, Osborne Street and nearby roads. The new network connects into an existing 1,800-millimetre stormwater tunnel, boosting overall capacity.
Auckland Council’s General Manager Healthy Waters and Flood Resilience Craig Mcilroy, says the benefits will build over time.
“This is about long-term improvements, not quick fixes.
“As each stage comes online, we’re increasing network capacity, reducing wastewater overflows and improving the quality of water flowing into Hobson Bay.”
The project is also setting new benchmarks in New Zealand stormwater construction. It includes Auckland’s first segmental stormwater shaft with a customised seismic design, and the deepest segmental shaft ever built in the country, reaching 23 metres underground. Using precast segments manufactured off-site has reduced construction time, saved around $2 million and minimised disruption for nearby businesses and the university campus.
Once complete, the new system will reduce wet-weather wastewater overflows, improve stormwater quality through a gross pollutant trap, and reduce flooding risk by handling rainfall from a 1-in-100-year storm event.
Auckland Council thanks residents, businesses and commuters for their patience while crews work beneath the streets, laying the foundations for cleaner water, safer beaches and a more resilient city.