While Iraq's population isn't as large as Turkey's, it is quite a bit larger than Syria's so Iraq should get more water than Syria.
Since not all of Iraq's water is renewable, their a out of water is going to start decreasing.
Iraq uses almost all of their water for agriculture. If they get less water, they will have to cut back on agriculture which could mess up their entire economy.
More of Iraq's water comes from other places than from Iraq. That means that if these other places stop giving them water, they will really be in trouble.
Iraq's population is going to really jump up and if they still don't have much water by then, there will not enough for everyone to survive.