The groundwater resources of the West Coast are substantial and are an important source of water for drinking, agriculture, and other industries and users. Most groundwater resources across the West Coast are located in alluvial materials adjacent to major rivers such as the Grey and Hokitika. Groundwater quality is monitored at 28 wells across the region.
Overall, groundwater quality remains relatively diluted due to high rainfall and contributions from large river systems. Nitrate concentrations assessed across the region in 2018 were higher than concentrations from previous years, with three locations periodically exceeding the New Zealand Drinking Water Standards for nitrate. Microbial contamination remains an issue, with E. coli detected above the New Zealand Drinking Water Standards at 62% of wells. Elevated nitrate and E. coli is potentially an issue if water from these wells is consumed.
State of Groundwater Quality Reports
The West Coast Regional Council monitors groundwater quality in samples from seven National Groundwater Monitoring Programme wells, water level data and 22 other wells. This programme assesses the groundwater quality states and trends at these selected sites and summarises the results from the Monitoring Programme.