Chu River, river in Kyrgyzstan and Kazakhstan, rising in the Tien Shan at the confluence of the Dzhuvanaryk and Kochkor rivers. It flows north through the Boam Gorge, beyond which it is joined by the Chon-Kyomin; it then flows northwest through the fertile Chu Valley, in which much of its water is used for irrigation, before finally disappearing into the sands of the Moyynqum Desert. The Chu River’s total length is 663 miles (1,067 km), and it drains a basin of 24,150 square miles (62,500 square km).