Motairehe Marae, Wastewater Scheme

Client:                      Motairehe Marae Trust Board
Location:                Katherine Bay, Great Barrier Island
Project Value:       Undisclosed
Sector:                    Bi-cultural, 3 Waters
Completion:          208


Motairehe Marae is located in Katherine Bay, on the north-western coast of Aotea (Great Barrier Island).  The whare was opened in 1983.

The Motairehe Marae Trust Board was successful in its application for a grant from The Great Barrier Island Local Grants Board to upgrade its wastewater facilities.  Funding criteria was based on, Mana Whenua will prosper, the environment is protected and the Island’s infrastructure is resilient.

GWE Consulting Engineers undertook a review of the poorly performing existing wastewater system, comprising a septic tank and disposal trenches.  The existing base flow is from up to 5 permanent staff members and monthly gatherings that take place over two nights and comprise 30 to 40 guests

    Approximately twice-yearly larger events will result in approximately 80-100 guests being on the Marae e.g. tangis.  

    The design of the new system has allowed for all wastewater generated from the buildings to be treated within a new secondary wastewater treatment plant (with buffer tank).  Secondary effluent is discharged on site via a PCDI irrigation system located at surface on the elevated slopes of the Marae site.

    Design challenges included highly variable flows, steep land disposal area and no permanent power.


    • Infrastructure review and options study
    • Application of the Te Aranga Māori Design Principles
    • Wastewater treatment design
    • Land disposal of treated effluent
    • Operations and management plan