Ilek (river)

The Ilek (, "Elek", ) is a steppe river at the southern end of the Ural Mountains. It is a left tributary of the Ural and lies in Orenburg Oblast in Russia and Republic of Kazakhstan. It is long, and has a drainage basin of . It rises just south of Orsk, flows south a short distance and then flows westward south of and parallel to the river Ural, with many meanders and oxbow lakes, and joins the Ural about west of Orenburg. Two main cities lie on the banks of the Ilek River: Sol-Iletsk and Aqtöbe (alternate spelling: Aktöbe, Aktyubinsk). 
The Ilek remains the most polluted water body in the Ural-Caspian basin. The content of boron and chromium in the river is caused by the tailing ponds of former chemical plants via ground water. The pollution level varies from "polluted" to "very polluted". Tributaries of the Ilek include the Bolshaya Khobda and the Qarghaly. It is also of archeological significance since it has been discovered as the site of certain Kurgan (Indo-European) burials.
There are catfish, carp, perch, pike, etc. in the Ilek. It is used for water supply of industrial enterprises, irrigation of agricultural lands.