Behind it, a reservoir eight miles long holds eleven billion cubic metres of water
According to Engineering News-Record, its actually 12.5 billion cubic meters, but that may have been before the maximum water level was reduced to remove stress: http://web.archive.org/web/20030808092931/http://enr.construction.com/news/front2003/archives/030505.asp
extending nearly two miles from embankment to embankment.
Actually barely 1.5 miles https://www.google.com/maps/place/Mosul+Dam/@36.6149345,42.7910522,13164m/data=!3m1!1e3!4m6!3m5!1s0x40087171c23c189f:0x341308438b886b05!4b1!8m2!3d36.6325324!4d42.8170276
twenty-five miles north of Mosul
Measurable with Google Maps - https://www.google.com/maps/place/Mosul+Dam/@36.2120055,42.2766295,210279m/data=!3m1!1e3!4m6!3m5!1s0x40087171c23c189f:0x341308438b886b05!4b1!8m2!3d36.6325324!4d42.8170276
Two months earlier, ISIS had captured Mosul, a city of nearly two million people, as part of a ruthless campaign to build a new caliphate in the Middle East.
Mosul was captured by ISIS forces by June 10th, 2014. https://en.wikipedia.org/wiki/Fall_of_Mosul