Warka Water Tower: An Innovative Method of Water Harvesting from Thin Air in Semi-Arid Regions

Semi-arid region is a region where the rainfall varies from 250 mm to 650 mm per year. Because of less rainfall, high evapo-transpiration, surface and ground water availability is very less in these regions. It leads to water scarcity and drought conditions. Conventional water harvesting structures are not suitable in these regions. Hence there is need to go for alternative solution such as water harvesting from thin air. The aim of this research work is to find alternative method of water harvesting from thin air to overcome drinking water problems in semi-arid regions. The objective of this study is twofold, firstly to carryout comparative analysis of different water harvesting structures from thin air and secondly to carryout feasibility and cost analysis of Warka Water Tower in semi-arid region. In this research work, different water harvesting structures from thin air were studied and Warka Water Tower was found to be most economical and convenient because of its low initial cost, zero energy requirement and less maintaince cost and easy availability of construction material. The rate of discharge of a Warka Water Tower is 100 lit per day, however its efficiency can be increased with suitable conditions. Hence Warka water tower can be effectively used for drinking water purpose in semi-arid regions. In this study, feasibility analysis of Warka Water Tower was carried out and it was found that the structure is suitable at temperature 40 degree Celsius and relative humidity 50 -70 %. Cost analysis shows that the cost of a single warka tower is 33, 000 rupees.