Kalkutan

The Kalkutan () or Koluton () is a river of the Akmola Region, Kazakhstan. It has a length of and the size of its basin is .

==Course== The Kalkutan is a right tributary of the Ishim. It has its sources in lake Shortankol, by Novorybinka village. The river flows roughly westwards all along its course. It joins the right bank of the Ishim a little to the north of Kalkutan railway station. Its main tributaries are the long Talkara, the long Boksyk, the long Ashchysai, and the long Arshaly from the right.