Publisher Summary Water is the world's most valuable and wasted resource. With growing demand outstripping supply in many regions of the world, the situation is likely to get exasperated soon. Less than 3% of the world's water is considered safe for human consumption. It is estimated that less than 1.0% of the world's water supply is easily accessible and has acceptable water quality. According to the National Council Research Report, the principal water problem in the early 21st century will be inadequate and uncertain supplies. Because water availability includes both water quality and quantity, reduction in water quality due to water pollution further diminishes the available water. World's water needs can be met by better water management, that is, by reducing losses using micro-irrigation techniques, most of the 66% water lost during irrigation can be recovered by using advanced water treatment technologies for treating polluted water and for reclaiming water, and by conservation.