Due to rapid increase in population, the demand for water continues to increase globally in almost all sectors. However, the temporal and spatial variability of the available water resources can no longer be taken for granted particularly under changing climate. Heavy water consumers such as agriculture and industry often contribute to its contamination. In urban areas, huge quantities of sewage wastes are generated every day and discharged directly to rivers contaminating their water and its consumption badly affects the health of human beings thriving on it. Water distribution networks and soiled water collection systems pose serious problems and there is a need to maintain ageing infrastructures mostly in urban areas.
Shortage of water further has social, economic, and political implications. In many regions of the world, people are relying heavily on energy demanding pumping systems for the supply of water. It has led to depletion of ground water and caused salt water intrusion, particularly in coastal areas. Expensive desalination systems are being used to meet the needs of coastal population.
Various technological solutions have been proposed to optimize the use of water, particularly by recycling waste water for agricultural and secondary uses. Over and above, the climate change has significantly affected the hydrological extremes causing economic losses to the society.