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Iskar (river)

geography Maturity 7-9 Next article →

The Iskar is a major river in Bulgaria. It is 368 km long. This length makes it the longest river that stays entirely within Bulgaria. Other rivers, such as the Danube, are longer. However, those rivers flow through multiple countries. The Iskar is a right tributary to the Danube. It also forms part of the Black Sea river basin. This river is unique because it is the only one that starts in southern Bulgaria and flows north through the Balkan Mountains. These mountains act as a water divide. They separate the Black Sea basin in the north from the Aegean Sea basin in the south.

Geologically, the Iskar is the oldest river in the Balkan Peninsula. It is also the only river to keep its original direction. This happened despite many significant geological changes over time. The river's watershed drains an area of 8,617 km2. This area covers parts of six Bulgarian provinces. These include Sofia, Sofia City, Vratsa, Lovech, and Pleven. About 1,600,000 people live within the Iskar basin. The river flows through nine towns and many villages.

IskaratGerman
IskaratGerman

The river begins as three separate forks in the Rila mountain range. Rila is the highest mountain range in Bulgaria. The first fork is the Cherni Iskar. It is 23 km long and is considered the main stem. It starts at Chamovsko Lake at an altitude of 2,500 m. The second fork is the Beli Iskar. It is the longest fork at 28 km. Its springs are at the Redzhepitsa Peak. The Musalenska Bistritsa is a tributary of the Beli Iskar. It begins at the Musala Lakes near the highest summit in the Balkan Peninsula.

Central Rila Reserve3
Central Rila Reserve3

The third fork is the Levi Iskar. It is the smallest fork at 18 km long. These three forks eventually join to form the Iskar proper.

As the river moves, it passes through several important features. The Iskar flows through the Samokov valley at 950 m altitude. It then fills the Iskar Reservoir. This is the largest artificial lake in Bulgaria. After the dam, the river forms the 22 km long Pancharevo Gorge. This gorge divides the Vitosha and Plana Mountains from the Sredna Gora range.

IskaratGerman
IskaratGerman

The middle course begins near the village of German. Here, the river enters the Sofia Valley. The river flows through the eastern suburbs of Sofia. It even crosses the runway of Sofia International Airport. In this valley, the riverbed changes. It carries rough gravel upstream and sand downstream.

The Iskar then enters the Balkan Mountains at Novi Iskar. It forms the spectacular Iskar Gorge. This gorge is 84 km long. The rock walls are very high. They reach heights between 200 m and 500 m.

Panoramic view of Iskar gorge
Panoramic view of Iskar gorge

The river flows through different types of rock here. In some places, it runs through mesozoic limestone. This makes the gorge look like a narrow canyon. At Lakatnik, the river turns east. It flows through very eroded rocks. The gorge is wide here and has river terraces. These terraces are 110 to 120 m high.

Стара Планина Искърски пролом 003
Стара Планина Искърски пролом 003

After the mountains, the river enters the Danubian Plain. It flows north-east until it meets the Danube. This confluence is near the villages of Baykal and Gigen.

The Iskar is very important for the economy of Bulgaria. It provides water for the capital city, Sofia. It also provides water for many manufacturing plants. People use the water for irrigation and for generating electrical energy. The river is not navigable for large boats. However, the Iskar Gorge is a vital transportation route. It is one of only three passes in the Balkan Mountains used by a railway.

Panoramic view of Iskar gorge
Panoramic view of Iskar gorge

The scenic gorges and rock formations also attract people for recreation.

Many animals live in the Iskar river system. There are more than 50 species of fish. These include jawless fishes and ray-finned fishes. Some fish are endemic, meaning they are found only in certain areas. For example, the Cottus haemusi lives in the upper Iskar and Vit drainages. The wels catfish is the only member of its order in Europe. The river also supports various amphibians like frogs and newts. You can also find reptiles such as turtles and several types of snakes.

IskaratGerman
IskaratGerman

The headwaters of the river are located inside Rila National Park. Parts of the river are also protected by the Natura 2000 network.

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🖼️ Images & Media (4)
File:Central Rila Reserve3.jpg
Central Rila Reserve3.jpg
File:Panoramic view of Iskar gorge.jpg
Panoramic view of Iskar gorge.jpg
File:IskaratGerman.JPG
IskaratGerman.JPG
File:Стара Планина Искърски пролом 003.jpg
Стара Планина Искърски пролом 003.jpg
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