Vltava

Vltava from Bohnice viewing point

The Vltava river is 430.3 kilometres (267.4 mi) long and drains an area 28,090 square kilometres (10,850 sq mi) in size, over half of Bohemia and about a third of the Czech Republic's entire territory.[7][6] As it runs through Prague, the river is crossed by 18 bridges (including the Charles Bridge) and covers 31 kilometres (19 mi) within the city.[8] The water from the river was used for drinking until 1912, when the Vinohrady Water Tower ceased pumping operations.[9] It is, however, the source of drinking water in case of failures of or repairs to the water supply from the Želivka and Kárané sources. The Podolí water processing plant is on standby for such cases with the long section of the river upstream of the Podolí plant under the stricter, second degree of pollution prevention regulations.

The height difference from source to mouth is about 1,016 metres (3,333 ft) and the largest stream at the source is named Černý Potok (Black Brook) or Teplá Vltava (Warm Vltava). The Vltava itself originates by a confluence of two streams, the Warm Vltava (Teplá Vltava), which is longer, and the Cold Vltava (Studená Vltava), sourcing in Bavaria. Along its course, Vltava receives many tributaries, the biggest being Otava and Berounka from the left and Lužnice and Sázava from the right side.

"Náplavka Smíchov" ferry dock in Prague

Between the confluence with the Elbe at Mělník and Prague, the river is navigable by vessels of up to 1,000 tonnes (980 long tons; 1,100 short tons) displacement. Most of the river upstream of Prague as far as České Budějovice is currently navigable by craft of up to 300 tonnes (300 long tons; 330 short tons) displacement, but such vessels cannot pass the dams at Orlík and Slapy, and are also restricted by a low bridge at Týn nad Vltavou. Work is planned to complete boat lifts, planned for but never completed, at the two dams, and to rebuild the bridge, in order for them to navigate throughout. Much smaller craft, of up to 3.5 tonnes (3.4 long tons; 3.9 short tons) displacement and under 3 metres (9.8 ft) beam and 3 metres (9.8 ft) air draft, can avoid these obstacles.[10]

Upstream of České Budějovice, the river's section around Český Krumlov (specifically from Vyšší Brod to Boršov nad Vltavou) is a very popular destination for water tourism.[11][12]

Historic Centre of Český Krumlov near Vltava river

Nine hydroelectric dams have been built on the Vltava south of Prague to regulate the water flow and generate hydroelectric power, starting in the 1930s. Beginning at the headwaters, these are: Lipno, Lipno II, Hněvkovice, Kořensko, Orlík, Kamýk, Slapy, Štěchovice and Vrané. The Orlík dam supports the largest reservoir on the Vltava by volume, while the Lipno dam retains the largest reservoir by area. The Štěchovice Reservoir is built over the site of the St John's Rapids.

The river also features numerous weirs that help mitigate its flow from 1,172 metres (3,845 ft) in elevation at its source near the German border to 155 metres (509 ft) at its mouth in Mělník.

The Vltava basin has flooded multiple times throughout recorded history. Markers have been created along the banks denoting the water line for notable floods in 1784, 1845, 1890, 1940, and the highest of all in 2002.[13][14][15]

In August of that year, the basin was heavily affected by the 2002 European floods when the flooded river killed several people and caused massive damage and disruption along its length, including in Prague. It left the oldest bridge in Prague, Charles Bridge, seriously weakened, requiring years of work to repair.[14]

Prague was again flooded in 2013. Many locations within the Vltava and Elbe basins were left under water, including the Prague Zoo, but metal barriers were erected along the banks of the Vltava to help protect the historic city centre.[16][17]

The Vltava as it flows along the north side of central Prague, taken from the Stalin Monument socle in Letná Park

One of the best-known works of classical music by a Czech composer is Bedřich Smetana's Vltava, sometimes called The Moldau in English. It is from the Romantic era of classical music and is a musical description of the river's course through Bohemia (listen).

A minor planet 2123 Vltava discovered in 1973 by Soviet astronomer Nikolai Stepanovich Chernykh is named after the river.[18]

Smetana's symphonic poem also inspired a song of the same name by Bertolt Brecht. An English version of it, by John Willett, features the lyrics Deep down in the Moldau the pebbles are shifting / In Prague three dead emperors moulder away.[19]

• Moldavite

• Geographic data related to Vltava at OpenStreetMap