Reclaimed water to face agricultural water scarcity in the Mediterranean area: An overview using Sustainable Development Goals preliminary data

Climate change is exacerbating the existing water scarcity issue in the Mediterranean area, leading to unprecedented pressure on water supply, especially in arid regions. Current changes and future scenarios all indicate significant and increasing water demand during the coming decades. Water demand is further aggravated by the population growth, which consequently increases demand for crops and agricultural products. The use of reclaimed water (RW) seems to be a promising alternative and valuable water resource, particularly for agriculture, which is currently the main user of renewable water resources. In addition to preserving freshwaters, the use of RW for irrigation would represent a source of nutrients, namely nitrogen, phosphorus, and other salts, which are necessary for the physiological growth of crops. For the Mediterranean area, it was possible to investigate on the significance of the RW use through the comparison of different data such as the total amount of generated wastewater, which represents the potential of using RW as an irrigation source, and irrigation water requirement, respectively. The analysis showed that the use of RW could significantly decrease the current pressure on total renewable water resources, and therefore help to face water scarcity and climate change issues. Nevertheless, for the Mediterranean area, there are still limiting elements such as the non-existence of a univocal regulatory framework on the use of RW for irrigation purposes as well as a lack of data on real quantities of wastewater that are safely treated, collected and generated.