Whangārei Wastewater Treatment Plant Masterplan
At a glance
This framework outlined immediate actions for the next 10 years, as well as establishing a roadmap for ongoing adaptation and evolution over the plant's anticipated 35-year consent period.
The challenge
Servicing a population of 65,000 in the urban area of Whangārei, the Whangārei wastewater treatment plant (WWTP) faces significant uncertainties over the next 35 years and beyond regarding future regulations, discharge requirements, population growth and climate change impacts. The plant required staged upgrades to maintain and improve current plant performance in response to these drivers. Whangārei District Council needs and community desires were also identified, influencing planning objectives and outcomes. Amid these uncertainties, maintaining the long-term sustainability of the Whangerei WWTP and identifying the timeframes and quantum of the investment required, posed a considerable challenge.
Our response
To address the challenges facing the Whangārei WWWP, GHD applied an Adaptive Pathways Planning approach. This involved an in-depth assessment of potential upgrade options, considering a wide range of factors influencing the plant's future, such as regulatory changes, population growth projections and climate variability.
Drawing on extensive consultation with key stakeholders, including the Whangārei District Council and local community groups, our team developed a 'living' Masterplan. This framework outlined immediate actions for the next 10 years, as well as establishing a roadmap for ongoing adaptation and evolution over the plant's anticipated 35-year consent period.
Our approach emphasised adaptability, monitoring of key factors and responsiveness, recognising the inherent uncertainties of long-term planning in a rapidly changing environment. By incorporating triggers for decision-making and thresholds for action, our Masterplan ensured that the WWTP remained resilient in the face of evolving challenges and enabled the investment profile to be identified.
Furthermore, our methodology integrated methods to gather the latest data and research on discharge quality, environmental impacts and climate projections, providing a solid foundation for informed decision-making. This data-driven approach enabled our project team to anticipate and mitigate potential risks and to adapt as triggers are reached.
In addition to technical considerations, GHD prioritised community engagement and stakeholder collaboration throughout the planning process to ensure the Masterplan reflected the values and priorities of the local community, enhancing its long-term viability and acceptance.
The impact
The Adaptive Pathways Planning approach enabled Whangārei District Council to respond effectively to short- and medium-term needs while maintaining flexibility for long-term options. This approach allowed for greater agility in responding to changing drivers and will enable effective management and upgrade of the plant over the next 35 years and beyond.
The 'living' Masterplan and Adaptive Pathways Planning approach formed the basis of Council's consent renewal application, emphasising the continuous monitoring and management of the WWTP’s performance to minimise environmental impacts.
Stakeholder engagement also played an integral role to the setting of objectives and ongoing success of the plan, with a commitment to intentional ongoing community involvement and transparency of decision making.