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
Tigris–Euphrates river system stations. On September 19, 2009, Turkey formally agreed to increase the flow of the Euphrates River to 450 to 500 m³/s, but only until October 20, 2009. In exchange, Iraq agreed to trade petroleum with Turkey and help curb Kurdish militant activity in their border region. One of Turkey's last large GAP dams on the Tigris – the Ilisu Dam – is strongly opposed by Iraq and is the source of political strife. The Mesopotamian Marshes in southern Iraq were historically the largest wetland ecosystem of Western Eurasia. Their drainage began in the 1950s, to reclaim land for agriculture and