The Chatkal is a river of Jalal-Abad Region, Kyrgyzstan and Tashkent Region in Uzbekistan. It is the left source river of the Chirchiq in the Syr Darya basin. In its upper course it is called Karakulja. The length of the river is 223 km, with a basin area of 7110 km2. It originates at the point where Chatkal Range adjoins Talas Ala-Too Range. Its largest tributaries are the Aksuu, Kokuybel, Avletim, Ters and Nayza (Oqbuloq) from the left, and the Karakysmak, Beshterek, Chandalash and Köksuu from the right. The average rate of water flow near the mouth is 122 m3/s, with a maximum 920 m3/s.