Great Zab River

…the left-bank junctions with the Great Zab and Little Zab rivers. During flood time, in March and April, the two Zabs double the volume of the Tigris, but their flow is controlled by the Bakhma and Dukān dams. The rapids of Al-Fatḥah Gorge impede navigation.

…of the Tigris, notably the Great and Little Zab rivers and the Diyālā and ʿUẓaym (Adhaim) rivers. These streams weave tortuously south and southwest, cutting through ridges in a number of gorges, notably the Rū Kuchūk gorge, northeast of Barzān, and the Bēkma gorge, west of Rawāndūz town. The highest…