Planning a future-ready sewer upgrade for Te Puke

Western Bay of Plenty District Council (WBoPDC) identified the need to upgrade the final sections of the trunk sewer discharging to the Te Puke Wastewater Treatment Plant to support future growth. PDP was engaged to provide professional services for the trunk main renewal, alongside the wider treatment plant upgrade.

Our team assessed four potential alignment options, including routes north and south of the KiwiRail East Coast Main Trunk, using a multi-criteria analysis aligned with NZ Transport Agency Waka Kotahi guidance. Preliminary investigations and desktop studies covered contaminated land, geotechnical conditions, and planning considerations, ensuring risks and constraints were well understood early.

We developed three vertical profile options for each alignment and undertook comparative assessments, including and excluding construction costs, to support robust decision making. Geotechnical site investigations were then completed for the preferred option, to better understand ground conditions and inform design.

PDP then delivered the preliminary design for the selected alignment, incorporating feedback from WBoPDC’s operations team. Modelling indicated the existing main could accommodate near-term growth, so the project was paused. To support future delivery, we prepared a comprehensive design package, covering drawings, pipe sizing and material selection, risk assessments, planning inputs, and construction cost estimates. We also completed a KiwiRail grant application for works within the rail corridor. This work provides WBoPDC with a clear, well-documented pathway to progress the upgrade when required, ensuring continuity and confidence in future design stages.