Long-Term Solution for the Lower Waihao Rural Water Scheme

Waimate District Council has taken a significant step toward securing a long-term solution to elevated nitrate levels in the Lower Waihao Rural Water Scheme. A resource consent application has been lodged with Environment Canterbury for a new water source located near Bells Pond, Ikawai.

Over recent years, the scheme has experienced occasional spikes in nitrate levels, including instances where levels exceeded the Maximum Acceptable Value (MAV). The most recent breach in December 2024 prompted a ‘cease water consumption’ notice until levels returned to safe limits.

In response, Council swiftly implemented an emergency temporary solution by sourcing water from the Waitaki River, which provided water at reduced nitrate levels well below MAV. At the same time, work began to identify a permanent alternative water source.

Following months of sampling and raw water quality testing, the new source near Bells Pond was selected for its excellent water quality and, crucially, its very low trace levels of nitrate.

The solution includes approximately 4.5 kilometres of new pipework connecting the new source to the existing treatment plant, along with minor modifications to the plant itself. The current bore will be retained for resilience, provided it remains compliant with Drinking Water Standards.

This solution replaces the previously proposed denitrification plant and offers several key advantages: it can be set up much faster and will result in considerably lower operating costs, ultimately saving ratepayers money.

This milestone has been achieved through close collaboration with key stakeholders, including landowners, Morven Glenavy Ikawai Irrigation (MGI), Te Rūnanga o Waihao, and industry representatives. MGI played a pivotal role in engaging with shareholders and helping shape a robust and sustainable solution.

Council acknowledges the considerable work undertaken by staff to prepare the resource consent application. The process involved hydrological assessments, environmental impact evaluations, engineering design, easement agreements, and comprehensive surveys.

While the nitrate issue is not of Council’s making, ensuring safe drinking water remains a top priority.

Chief Executive Stuart Duncan says, "We are excited to finally put this issue behind us and do what is best for our residents. The lodging of the resource consent marks the beginning of the final phase. Once approved, Council will move quickly to issue a tender for construction works.”