Tigris–Euphrates river system border. Since the 1960s and in the 1970s, when Turkey began the GAP project in earnest, water disputes have regularly occurred in addition to the associated dam's effects on the environment. In addition, Syrian and Iranian dam construction has also contributed to political tension within the basin, particularly during drought. The general climate of the region is subtropical, hot and arid. At the northern end of the Persian Gulf is the vast floodplain of the Euphrates, Tigris, and Karun Rivers, featuring huge permanent lakes, marshes, and forest. The aquatic vegetation includes reeds, rushes, and papyrus, which support numerous species. Areas
Water politics in the Jordan River basin Water quality is variable in the river basin. The three tributaries of the upper Jordan have a low salinity of about 20 ppm. The salinity of water in Lake Tiberias ranges from 240 ppm in the upper end of the lake (marginal for irrigation water), to 350 ppm (too high for sensitive citrus fruits) where it discharges back into the Jordan River. The salt comes from the saline subterranean springs. These springs pass through the beds of ancient seas and then flow into Lake Tiberias, as well as the groundwater sources that feed into the lower Jordan. Downstream of Tiberias,