There was a little article in The Columbian (Iraq bans summer crops, AP, July 05, 2018) saying lack of irrigation water has caused the Iraqi government to ban summer crops like rice and corn in the once fertile plains south of Baghdad. Farmers blame the government, lack of rainfall, and the Turks who have dammed the Tigris and Euphrates rivers.
This is the beginning of modern water wars. In Syria, a significant part of the cause of the current civil war is the 2006-2011 severe drought and subsequent lack of farm employment and food. Article -LINK
The concept of war over water is one that has begun to surface in our time. Much of the problem is fueled by global warming or climate change. (We broke many temperature record in the US on July 07, 2018.) If there is no water from rivers or aquifers, there is no irrigation and then there is no food or income. Governmental agencies are typically blamed for bad management of water resources, and civil unrest is fomented.
In the U.S., we already have California wanting more Colorado River water, which is allocated to California and 6 other states, including Arizona. In the Northwest, the U.S. is to begin renegotiation of a 1964 Columbia River treaty with Canada over water and power distribution. Canada controls U.S. flooding with their large dams on the Columbia and in return we supply them with hydroelectric power. The U.S. seems to want more water released for Salmon habitat and less power transferred, to use internally. The U.S. is not negotiating in best form lately.
Arizona is in drought conditions and "could run out of water in six years", says one article. Water shortages are coming. It looks like water recycling, staving off climate change, and water use management are critical issues from now on. Water is becoming political and will no longer be a commodity.