The Isluga River (also known as Sitani or Arabilla) begins at the southern foot of the high Cerro Alpajeres west of the town of Chaguane at the confluence of the Chaguane and Huinchuta. In its upper parts the Isluga River is also known as the Arabilla River. The Chaguane is long and receives water from the Laguna Parinacota, which in turn is nourished from two creeks that join it from the west and north. The Huinchuta (also known as Pasijro) is also long but comes from the northwest and turns south before joining the Chaguane.