Is Desalination of Sea Water Cheaper than Constructing Damin Coastal Areas for Irrigation?

The essence of global water scarcity is the geographic and temporal mismatch between fresh water demand and availability. The increasing world population, improving living standards, changing consumption patterns, and expansion of irrigated agriculture are the main driving forces for the rising global demand for water. Climate change, such as altered weather-patterns (including droughts or floods), deforestation, increased pollution, green house gases, and wasteful use of water can cause insufficient supply. At the global level and on an annual basis, enough freshwater is available to meet such demand, but spatial and temporal variations of water demand and availability are large, leading to (physical) water scarcity in several parts of the world during specific times of the year. Through these reasons there is a need to go for alternative measures to mitigate the water scarcity. Desalination may be the best alternative measure for drinking, irrigation and domestic purposes of the people. Desalination is the cheapest available technology and cost of production of one litre drinking water is varies between ₹ 0.04 to 0.15 compared to reservoir i.e. ₹ 2 to 2.75 for project efficiency of about 50years.