Water advisories are public health notices warning that water may be unsafe for drinking or other uses. Boil water advisories require boiling water before consumption due to potential bacterial contamination. Do not consume advisories indicate contaminants that boiling cannot remove. Do not use advisories warn against any contact with the water. Water advisories result from contamination events, treatment system failures, or inadequate infrastructure. Long-term drinking water advisories affecting many First Nations communities have highlighted inequities in water infrastructure—some communities have lived under advisories for years or decades while most Canadian municipalities have reliable safe water. The federal government has committed to eliminating long-term drinking water advisories on reserves, though this remains ongoing work. Water advisories underscore the fundamental importance of safe drinking water infrastructure.