I was a Marine in Iraq from 06-09. We constantly built plans for the inevitable demise of this dam. Mostly just estimates of how screwed people would be.
I'm surprised it's not blown yet, I was constantly worried someone would bomb it somehow, but 7 years later, it's still standing, so I'm unsure about any estimates given now - the Iraqis were fairly liberal in their estimates in 2006 (it'll fall by 2007) and the same predictions followed every year. Of course, they wanted vast quantities of money to fix it (and skim off the top for themselves) so there was some bias.
Check out the Haditha Dam too. Another large body of water held back by aging infrastructure further destroyed by looters who dismantled huge pieces of machinery to sell as scrap for $0.05/lb.