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
Rainworth Water wetland habitats. Typical of such schemes is an area of wetland at Thieves Wood that would allow run-off from the A60 to deposit silt, and chemical contaminants to be removed before the water enters the main river. It would also create a head of water, which would be released into the river more slowly, levelling out the periods of high flow and low flow. The Environment Agency are responsible for measuring water quality of the river systems in England. Each is given an overall ecological status, which may be one of five levels: high, good, moderate, poor and bad. There