Ōtaki Wastewater Gravity Main - Stage 2 Trenchless Section

The Kāpiti Coast District Council invites tenders for the construction of Stage 2 of the Ōtaki Wastewater Gravity Main.

This stage involves trenchless installation of a DN400 gravity wastewater pipeline beneath the North Island Main Trunk rail line and the SH1 Ōtaki Expressway, using micro-tunnelling or pipe-jacking methods.

The works include associated connections, manholes, and reinstatement, and form part of a multi-stage upgrade to improve network resilience and capacity.

This is a single-stage procurement process under NZS 3910:2013 (with special conditions). Tenderers must demonstrate relevant experience in trenchless construction and compliance with KiwiRail and NZTA requirements.

The anticipated start date is January 2026, with a contract duration of approximately three months.