The UN gave a clear and precise definition of water security, describing it as: "The capacity of a population to safeguard sustainable access to adequate quantities of acceptable quality water for sustaining livelihoods, human well-being, and socio-economic development, for ensuring protection against water-borne pollution and water-related disasters, and for preserving ecosystems in a climate of peace and political stability."
While you might (understandably) connect water security with scarcity, the term also refers to other forms of inclement weather and inadequate resources. Threats to water security include drought, flooding, and poor quality or polluted water.
Water security concerns us all, though, naturally, it is a more pressing concern for some regions. Countries more acutely impacted by climate change face greater water security risks.