NZ InfraWatch
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WATER
Central Interceptor — Auckland Wastewater Tunnel
Watercare · Auckland
Auckland's 16.2km, 4.5m-diameter wastewater tunnel from Grey Lynn/Point Erin to the Māngere treatment plant, cutting wet-weather overflows into the Waitematā and Manukau harbours by ~80%. Cost ~$1.67b (up from $1.2b). The southern section went live in February 2025; the northern section is set to commission around mid-2026.
A
Breakdown▾
93% · Very likely to proceed
Completion Probability — likelihood this proceeds on roughly its stated timeline.
Each axis is a scoring factor (0–100%)
Key facts
- Region
- Auckland
- Sector
- Water
- Status
- Under Construction
- Estimated value
- $1.7b
- Indicative completion
- 2026
- Funding status
- Fully Funded
- Lead organisation
- Watercare
- Election risk
- Low
Election risk assessment
Critical utility infrastructure, fully funded by Watercare and nearly complete — low political risk.
Government priority alignment
HIGH — Critical three-waters infrastructure reducing harbour overflows.
Chronology
- 2019Main construction begins
- 2025Southern section commissioned; 16.2km tunnel breakthrough
- 2026Northern section targeted to go live