In this study, it is aimed to determine the irrigation water required due to solar radiation in high technology greenhouses where soilless cultivation is carried out according to TS825 standards, and to determine the annual water consumption and storage capacity with the harvested rainwater. As a result of the calculations made for Turkey Mediterranean region, it has been determined that if 90% of the rainfall in the western Mediterranean region is harvested, 72% of the annual water consumption can be met, and 45% in the eastern Mediterranean region. In the inner regions where the terrestrial climate is dominant, 22%–32% of the annual water consumption can be met with 90% of the rain harvested depending on the amount of rainfall. The required storage volume in the western Mediterranean is 0.420 m3.m-2, while it is 0.096 m3.m-2 in the eastern Mediterranean and 0.044 m3.m-2 in Kırşehir, where the continental climate prevails.