This event happens towards the end of the 7 year Tribulation, but clearly we see the making of it now, so the question is “how much closer are we to the beginning….”
And the sixth angel poured out his vial upon the great river Euphrates; and the water thereof was dried up, that the way of the kings of the east might be prepared. Rev 16:12
Saying to the sixth angel which had the trumpet, Loose the four angels which are bound in the great river Euphrates. Rev 9:14
And the four angels were loosed, which were prepared for an hour, and a day, and a month, and a year, for to slay the third part of men. And the number of the army of the horsemen were two hundred thousand thousand: and I heard the number of them. Rev. 9:15-16

Swarms of snakes are attacking people and cattle in southern Iraq as the Euphrates and Tigris rivers dry up and the reptiles lose their natural habitat among the reed beds…..
The collapse in the water levels of the rivers has been swift, the amount of water in the Euphrates falling by three-quarters in less than a decade. In 2000, the flow speed of the water in the river was 950 cubic metres per second, but by this year it had dropped to 230 cubic metres per second.
In the past, Iraq has stored water in lakes behind its own dams, but these reservoirs are now much depleted and can no longer make up the shortfall. The total water reserves behind all Iraqi dams at the beginning of May was only 11 billion cubic metres, compared to over 40 billion three years ago. One of the biggest dams in the country, on the Euphrates at Haditha in western Iraq, close to the Syrian border, held eight billion cubic metres two years ago but now has only two billion.
Looking for that blessed hope, and the glorious appearing of the great God and our Saviour Jesus Christ; Tit 2:13