The correct answer is Rajasthan.Explanation:Rajasthan is a hot and dry place.The availability of water resources varies over space and time, mainly due to the variations in seasonal and annual precipitation.Due to seasonal and very little rainfall in Rajasthan rainwater harvesting is done on rooftops and with the help of other rainwater harvesting structures.Most of the water that we get as rainfall just flows away.This is a waste of precious natural resources.The rainwater can be used to recharge the groundwater.This is referred to as water harvesting or rainwater harvesting.Additional InformationTanka:Tanka or Tank is a traditional rain-water harvesting technique in Rajasthan.Tanka is a circular or rectangular shaped pond with a life span of 3-4 years.Ranisar and Padamsar in Jodhpur, forest tank of Ranthambhor, Sukhsagar Tank and Padmini Tank are some famous ones.Bawri:Bawri's are deep step wells built into the ground.It was the traditional way of rainwater harvesting.When it rains, the water accumulates in the tank.They are built deep into the ground so that the water does not evaporate easily and can be used during water shortages.Johad:Johads are small earthen check dams that capture and conserve rainwater, improving percolation and groundwater recharge.A johad, also known as a pokhar or a percolation pond.3000 johads spread across more than 650 villages in Alwar district, Rajasthan.