Environment Canterbury recognises nitrate issue in Lower Waihao public water supply
We acknowledge that nitrate levels in our freshwater are too high in many parts of Waitaha/Canterbury, including the Lower Waitaki area.
As the regional council, we monitor surface water and groundwater across the region, sampling around 350 wells across Waitaha for a range of contaminants, including nitrate.
Our 2023 groundwater report indicates that the 10-year trend shows nitrate levels are very likely increasing in the area around Glenavy.
However, it is quite common for nitrate concentrations to fluctuate during the year, and peaks are often seen after significant rainfall – and even more so when that rainfall follows a relatively dry period.
Our regional plan contains rules limiting activities that can lead to nitrogen loss, and, in many areas, requirements for dairy farmers to lower their nitrogen loss over time. We work with our rural communities to drive good management practices for each farming type, in order to meet environmental outcomes over time. In areas where nitrate concentrations exceed plan limits, farmers are required to make further reductions that go beyond what’s required from good management practice.
Our policies focus on long-term trends, and reversing those increasing trends will take time. However, due to the elevated nitrate being observed in groundwater around Glenavy, we are working closely with the Waimate District Council on this issue, and our land management team has also been working with farmers in the catchment to map their high risk critical source areas to help reduce nitrogen and sediment run-off.