Early this month the Islamic State of Iraq and Syria (ISIS) closed the gates of the Falujah Dam, which is on the Euphrates five km (3 miles) south of Falujah, Iraq, causing extensive flooding in the Abu Ghraib area east of the dam and west of Baghdad.
The closure of the dam's gates also resulted in a severe decrease in the amount of water downstream, south of the dam, which is vital for irrigation and the generation of electricity.
The ISIS took control of the dam in February and Iraqi government forces have been trying to retake control of the area since then.
Hundreds of thousands of people are reportedly suffering from floods in some areas and water shortages in others due to the ISIS's actions.
From the April 14, 2014 Press Release of the U.S. Embassy in Baghdad:
The U.S. Embassy in Baghdad strongly condemns the ongoing terrorist acts by the so-called Islamic State of Iraq and the Levant (ISIL) and its supporters. In particular, targeting dams and other vital infrastructure victimizes innocent Iraqi citizens. In the past week, hundreds of thousands of innocent Iraqis have suffered from water shortages as a result of ISIL’s actions. This is in addition to ISIL's ongoing campaign of suicide bombings and terrorist attacks targeting innocent civilians.
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http://iraq.usembassy.gov/...
Media reports are a bit unclear but articles about this can be found at these links:
http://america.aljazeera.com/...
http://news.yahoo.com/...
http://www.dailystar.com.lb/...
http://www.aa.com.tr/...