Strengthening Water Resilience For Waihi – Waihi Water Treatment Plant Upgrade

Strengthening the resilience and reliability of the Waihi Water Treatment Plant was a key priority for Hauraki District Council (HDC), helping the Council address supply vulnerability during maintenance periods and move toward a future‑ready solution.

Serving around 4,900 residents, the plant faced supply shortfalls following its 2015 membrane upgrade, when the single membrane train was offline for maintenance. Working with Hauraki District Council, we provided clear analysis, insight, practical options, and delivery support for the next stage of investment.

We began by assessing the plant’s process limitations and developing upgrade pathways that balanced operational needs, resilience, and affordability. Working closely with Council stakeholders, we supported selection of the preferred option, installing a standby membrane train to maintain continuous supply during maintenance or unplanned outages. Delivering this solution required extending the existing membrane building and integrating new equipment into the live plant without disrupting operations.

To support delivery, we prepared the Principal’s Requirements for a Design and Construct approach, helping to clearly define performance expectations, operational constraints, and constructability considerations.

Throughout design, construction, and commissioning, we provided targeted technical oversight to help the project team navigate the complexities of upgrading a fully operational treatment facility. A major focus of our involvement was managing the risk of supply interruptions. By proactively reviewing design decisions, construction methodologies, and sequencing strategies, we helped maintain service continuity for the Waihi community throughout the upgrade.

The result is a cost-effective upgrade that significantly strengthens plant reliability and secures a robust water supply for the Waihi community now and into the future.