The Little Zab or Lower Zab (Arabic: الزاب الاسفل‎, al-Zāb al-Asfal; Kurdish: Zêy Koya‎ or Zêyê Biçûk; Persian: زاب کوچک‎, Zâb-e Kuchak; Syriac: ܙܒܐ ܬܚܬܝܐ‎, Zāba Taḥtāya) is a river that originates in Iran and joins the Tigris just south of Al Zab in the Kurdistan region of Iraq. It is approximately 400 kilometres (250 mi) long and drains an area of about 22,000 square kilometres (8,500 sq mi). The river is fed by rainfall and snowmelt, resulting in a peak discharge in spring and low water in summer and early fall. Two dams have been built on the Little Zab, regulating the river flow, providing water for irrigation and generating hydroelectricity. The Zagros Mountains have been occupied since at least the Lower Palaeolithic, but the earliest archaeological site in the Little Zab basin, Bar