Manapouri Generator Foundations

Working in a remote, fragile and challenging environment

Manapouri is New Zealand’s largest hydro station located within a UNESCO World Heritage site in one of New Zealand's most remote areas. Environmental safeguards were, therefore, paramount.  

The site is also subject to sometimes challenging climatic conditions, including high levels of rainfall. For example, during the project, 800mm of rain fell in just three days – more than Christchurch’s average yearly rainfall.

A further challenge was working within an operational power station, directly adjacent to live high-voltage equipment, which required a strong focus on stringent health and safety protocols.

The project was critical to the operation of the power station. The new transformers would provide the local power necessary to keep it running and ensure the continued supply of electricity to hundreds of thousands of homes and businesses.

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Careful planning and attention to detail

To address these challenges, we planned the work in meticulous detail. Multiple contingencies were put in place to ensure the work could be completed safely, environmental standards were met, and the project was finished within the required timeframes. This included ensuring that all plant and materials were available when required, given the remote location. Our project team also worked in close collaboration with Meridian’s onsite operational teams and other contractors including Electrix (now Omexom) and Delta, to ensure a holistic view of the requirements.  

The work was completed in two stages – one for each transformer base. Existing concrete slabs around the operational infrastructure were broken out and we self-performed the installation of two new in-situ concrete transformer bases. This included the installation and testing of rock anchors to ensure the required level of seismic strengthening was achieved. All work was completed in line with Seipp’s pre-approved Inspection and Test plan, which included hold points for inspection. To ensure safety, all our on-site staff underwent multiple sessions of sector-specific training.

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Achieving objects with multi-disciplinary in-house expertise

The project succeeded in meeting all objectives. Drawing on the multi-disciplinary engineering expertise at Seipp, our methodology ensured the construction of the new transformer bases were delivered on time and within the agreed budget. Environmental objectives were also met. Through careful planning around weather conditions, we were able to protect the concrete when poured, ensuring any runoff material was captured and not discharged into local stormwater drains, thus protecting Lake Manapouri.