Some West Coast residents are being told to boil their water after testing indicated the local water reservoir was contaminated.
The Buller District Council says Westport and Carters Beach residents should boil all water before drinking and using it for food preparation, until further notice.
The council said the Westport reticulation and treatment plant was being monitored and tested daily to assess the contamination risk.
Last week, essential water use restrictions were put in place for Westport and Carters Beach after flooding damaged a large section of the region's water pipeline.