Due to the many long tributaries creating a branchy system within the river's drainage basin, the short Kolubara drains relatively large area of 3,639 km2 (1,405 sq mi).

It flows eastward, through the villages of Suvodanje, Bobova, Majinović, Pričević and Zlatarić, and at the city of Valjevo meets the river Jablanica and forms Kolubara.

However, many large villages and towns are located in the vicinity of the Kolubara: Lajkovac, Jabučje, Lazarevac, Šopić, Skobalj, Vreoci, Mali Borak, Veliki Crljeni, Draževac, Mislođin and Barič, where it flows into the Sava.

Major mines are Rudovci, Kolubara (at Veliki Crljeni) and Kosmaj, with many surface digs being developed lately.

Because of its importance for industry and economy in general, the municipality of Lazarevac, to which the coal basin mainly belongs, was attached administratively to the City of Belgrade in 1971.

[4] The mining projects at Kolubara have been plagued with corruption: in 2011, 16 current and former members of Elektroprivreda Srbije, the operator, were arrested on suspicion of embezzlement.

[3] The process of displacement of the Kolubara river bed in an effort to make possible exploitation of the "Veliko polje G" coal seam began in 2007.

Phase 2 of the project was finished in July 2017 when another 2.6 km (1.6 mi) of the river was conducted into the new, displaced bed.