JUBAISH, Iraq  Throughout the marshes, the reed gatherers, standing on land they once floated over, cry out to visitors in a passing boat.

“Maaku mai!” they shout, holding up their rusty sickles. “There is no water!”

The Euphrates is drying up. Strangled by the water policies of Iraq’s neighbors, Turkey and Syria; a two-year drought; and years of misuse by Iraq and its farmers, the river is significantly smaller than it was just a few years ago. Some officials worry that it could soon be half of what it is now.

The shrinking of the Euphrates, a river so crucial to the birth of civilization that the Book of Revelation prophesied its drying up as a sign of the end times, has decimated farms along its banks, has left fishermen impoverished and has depleted riverside towns as farmers flee to the cities looking for work.

The poor suffer more acutely, but all strata of society are feeling the effects: sheiks, diplomats and even members of Parliament who retreat to their farms after weeks in Baghdad.