Control of the dam is split between ISIL and forces friendly to the United States.
The author also notes the dam in Iraq that could make that casualty count appear minor league if ISIL or some other jihadis hit that hard enough. I've mentioned my worries on that issue.
On the bright side, ISIL's effort to drive friendly militias away from the Syria dam failed:
U.S. backed Syrian forces repelled a major counter-attack by Islamic State militants holding out at the country's largest dam and in the nearby town of Tabqa, the group and activists said on Sunday.
ISIL is going down. Will they in desperation try to pull everything down around them in the hope that somehow God will allow them to survive and emerge victorious from the calamity?