Water quality and quantity will become the principal limiting factor for sustainable development in many countries across the world. "Everything living is created from water" is an ancient quotation, which closely describes the importance of water. Water insecurity is a social dilemma in the recent decades because of several factors. Moreover, the widespread presence of arsenic in groundwater, salinity in both surface and groundwater, and the insidious disaster of drought make the water insecure and the population faces water risk in their daily life. Safe drinking water as well as health problems is an issue of concern in many countries on all continents, particularly in Southeast and South Asia. Therefore, this chapter provides water insecurity issues in a broader viewpoint especially focusing on salinity, arsenic, and drought disaster that together enhance vulnerability of water sector.