The (, the right tributary to the
Sava river.
The Kolubara originates as the ''Obnica'', in the
Podgorina region of the western Serbia, on the
Povlen mountain under the ''Medvednik'' peak. It flows to the north, next to the village of Bobova, bends to the west (in this part the river is also known as ''Jadar''), and at the city of
Valjevo , it meets the river ''Jablanica'' from the south and forms the Kolubara, as the river is known for the remaining course. The Obnica is 25 km long.
The Jablanica also originates from the Povlen mountain, just few kilometers away from the Obnica, under the ''Jablanik'' peak. It curves around the
Parač mountain and next to the village of Balinović, before it meets the Obnica at Valjevo. The Jablanica is 24 km long.
This is also the beginning of the 90 km long region of the Kolubara valley, divided in two large parts, referred to as Upper (''gornja'') Kolubara and Lower (''donja'') Kolubara (around the
Belgrade 's suburb of
Obrenovac ).
At Valjevo, the Kolubara receives the river
''Gradac'' from the right and forms the Valjevo valley) between the surrounding mountains, in which it spills in several parallel flows. After Valjevo, the most populous city in western Serbia, there are no major settlements on the river, except for the villages of Mlađevo and Slovac and the river receives the right tributaries of ''Ribnjača'' and ''Lepenica'' and the left tributary of ''Rabas'' . At Slovac, near the confluence of the right tributary of the ''Toplica'', the Kolubara carved the epigenetic ''Slovačka sutjeska'' , which separates Upper and Lower Kolubara. Upper Kolubara constitutes most of the modern
Kolubara District of Serbia.
The Kolubara turns north and continues to flow in several parallel flows, receiving in this section its major tributaries: ,
Jabučje ,
Lazarevac ,
Šopić , Skobalj,
Vreoci , Mali Borak,
Veliki Crljeni ,
Draževac ,
Mislođin and
Barič , where it flows into the Sava.
Lower Kolubara itself is divided in two sub-regions, the (upper) Kolubara coal basin and the (lower) Obrenovac micro-region.
In
Neogene , the region of Kolubara was a huge bay of the
Pannonian Sea (''Kolubarski zaliv'') As a result of abundant vegetation in the ancient sea, region of Kolubara and neighboring Tamnava (around Kolubara's longest tributary) today are immense
Lignite field which covers over 1.200 km&
2. It is estimated that coal deposits are as much as 4 billion tons, with coal layers being to 50 m deep, and over 20 million tons of coal are being extracted each year. Major mines are ''Rudovci'', ''Kolubara'' (at Veliki Crljeni) and ''Kosmaj'', with many surface digs being developed lately.
A series of coal based power stations are built in the basin, including ''Kolubara'' (130 MW, at Veliki Crljeni), ''
Nikola Tesla B-1'' (in 1983) and ''Nikola Tesla B-2'' (both 615 MW, in Obrenovac).
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.
Due to the lots of long tributaries which create branchy system within the river's drainage area, the short Kolubara drains relatively large area of 3.639 km&
2. It belongs to the
Black Sea Drainage Basin .
The river is not navigable, but its valley is very important for transportation. Here are located Belgrade-Valjevo road, parts of Belgrade-
Šabac road, Ibarska magistrala (Highway of
Ibar ) and the
Belgrade-Bar Railway .
The Kolubara was the site of one of the major battles on the
Balkans in the
World War I , the
Battle Of Kolubara in 1914.
- ''Mala Prosvetina Enciklopedija'', Third edition (1985); Prosveta; ISBN 86-07-00001-2
- Jovan Đ. Marković (1990): ''Enciklopedijski geografski leksikon Jugoslavije''; Svjetlost-Sarajevo; ISBN 86-01-02651-6
