A news says 100 million hectares of plains in Iran suffer from water crisis. According to ORSAM Water Research Program, Iran is located in one of the most arid areas of the world. The average annual precipitation rate is 252 mm. This figure constitutes one third of the global precipitation rate. Under current climatic conditions; 179 mm (71 percent) of the rainfall evaporates. The average annual evaporation rate in Iran ranges between 1500 mm and 2000 mm. This figure is 1/3 of the world average. While this figure is 2000 mm/year in northern highlands of the country, it is 20 mm/year in desert area. Two thirds of Iran receives less rainfall than the average precipitation rate.