Kuhrang

Koohrang also known as Kouhrang and Kurang is the name of a river, originating in the Zagros mountains of western Iran, which joins the Dez River to form the Karun, Iran's largest (by volume) river. A series of tunnels (Kuhrang Tunnels) have been built since the 1950s to redirect some of the Kuhrang's water toward the Zayandeh River to meet the demands of increased population in Esfahan and Yazd provinces.