Year Completed: 2024

Client: Form Building & Developments Ltd

Scope of Works: Drainage – Public and Private Stormwater and Wastewater

Te Pūtahi Māori o Manurewa is a new school development that brings together Te Kura Kaupapa Māori (TKKM) o Manurewa (School #4229, years 1-8) and Te Wharekura o Manurewa (School #3113, years 9-13) from their respective sites to a new ‘greenfield’ site at 165 Browns Road, Manurewa, Auckland 2102.

Project Background

The project commenced in 2021 but faced delays due to drainage design issues. By the time we began work in late 2023, the school buildings were already constructed, necessitating strict adherence to tight timeframes. Despite the challenges posed by the wet season and heavy rains, as well as coordination with other trades, we completed the project in 4 months, significantly ahead of the expected 6-month schedule.

Scope of Work

Our scope of work included the installation of both stormwater and wastewater systems:

• Pipe Installation: Laying PVC and concrete pipes ranging from 100 mm to 600 mm in diameter.
• Detention Tanks and Manholes: Installation of detention tanks, manholes, and cesspits, with manhole depths reaching up to 3 meters. This required the use of trench boxes and trench shields for safety.
• Stormwater Management: Installation of SW360 Stormfilters and threshold perimeter drains.
• Stormwater System: Setup of a large Cirtex Triton Stormwater System measuring 70.04 m in length, 6.64 m in width, and 1.19 m in height. This was particularly challenging due to the high water table and unstable ground, which we managed using dewatering systems and adapted methodologies.
• Directional Drilling: Directionally drilled approximately 260 meters of sewer lines. This method was chosen due to the depth of the lines and the time constraints.

Key Challenges and Solutions

• Time Constraints: Completed the project within 4 months despite the initial 6-month estimate, by closely coordinating with other trades and optimizing our workflow.
• Adverse Weather: Overcame heavy rains and wet conditions by adjusting our schedule and employing efficient water management techniques.
• Unstable Ground: Managed high water table and unstable soil conditions using dewatering systems and changing our methodology to suit the site conditions.

Outcome

Despite the numerous challenges, we successfully completed the drainage and wastewater systems for Te Pūtahi Māori o Manurewa on time and within budget, ensuring the new school development had reliable and effective infrastructure.