# Ohře

The Ohře (Czech pronunciation: ), also known in English and German as Eger (German pronunciation: ), is a river in Germany and the Czech Republic, a left tributary of the Elbe River. It flows through the Bavarian district of Upper Franconia in Germany, and through the Karlovy Vary and Ústí nad Labem regions in the Czech Republic. It is 304.6 km (189.3 mi) long, of which 256 km (159 mi) is in the Czech Republic, making it the fourth longest river in the country.

## Etymology

The name is of Celtic or pre-Celtic origin. In the 9th century, it appeared as Agara. According to one theory, its meaning was 'salmon river' (composed of the words ag, eg – 'salmon', and are, ara – 'flowing water'). Another theory suggests that the name was derived from agriā and meant a fast-moving, fast-flowing river. In the 12th century, Ohře was written as Egre, Oegre and Ogre.

## Course

The Ohře originates in the territory of Weißenstadt in the Fichtel Mountains at an elevation of 752 m (2,467 ft), below the Schneeberg mountain. It flows to Litoměřice, where it enters the Elbe River at an elevation of 143 m (469 ft).
The Ohře flows through the Fichtel Mountains in an eastward direction, through Lake Weissenstadt (Weißenstädter See) and through the towns of Röslau and Marktleuthen, and, after almost 50 km, reaches the Czech-German border near Hohenberg an der Eger. It then flows through the historic region of the Czech Republic which was known until 1945 as Egerland. The river passes the towns of Cheb, (German: Eger, like the river), Loket, Sokolov, Karlovy Vary, Klášterec nad Ohří, Kadaň, Žatec, Louny, Libochovice, Budyně nad Ohří and Terezín before flowing into the river Elbe at Litoměřice.
The river is 304.6 km (189.3 mi) long, of which 256 km (159 mi) is in the Czech Republic, making it the fourth longest river in the Czech Republic. The German part of the river (including the border section) is 49.8 km (30.9 mi) long.
The highest volume flow rate occurs in spring. The average volume flow rate at the mouth is 37.94 m³/s. The lower part of the river flows through areas with the lowest average precipitation in the Czech Republic (400–500 mm).

### Drainage basin

The Ohře's drainage basin has an area of 5,606.1 km$^2$ (2,164.5 sq mi). The area of the drainage basin in the Czech Republic is 4,601.1 km$^2$ (1,776.5 sq mi), in Bavaria is 920.4 km$^2$ (355.4 sq mi). The rest of the drainage basin is in Saxony.
The drainage basin is divided to further third-level basin areas:
| Basin code | Basin name | Area (km$^2$) |
| 1-13-01 | Ohře to the confluence with Teplá | 2,471.0 |
| 1-13-02 | Teplá and Ohře to the confluence with Liboc | 1,147.1 |
| 1-13-03 | Liboc and Ohře to the confluence with Chomutovka | 1,262.7 |
| 1-13-04 | Ohře from Chomutovka to the mouth | 725.3 |

### Tributaries

The longest tributaries of the Ohře are:
| Tributary | Length (km) | River km | Side |
| Wondreb / Odrava | 66.1 | 224.1 | right |
| Teplá | 65.1 | 175.3 | right |
| Blšanka | 50.8 | 81.3 | right |
| Chomutovka | 50.4 | 65.8 | left |
| Röslau / Reslava | 46.4 | 252.3 | right |
| Liboc | 46.4 | 91.1 | right |
| Svatava / Zwota | 41.0 | 203.0 | left |
| Rolava | 36.6 | 177.4 | left |
| Libocký potok | 31.8 | 219.4 | left |
| Bystřice | 29.6 | 153.8 | left |
| Plesná / Fleißenbach | 29.1 | 226.6 | left |
| Prunéřovský potok | 24.7 | 126.4 | left |
| Hasina | 24.4 | 69.8 | right |
| Smolnický potok | 23.6 | 47.0 | right |
| Libava | 22.7 | 216.9 | right |
| Chodovský potok | 22.7 | 178.0 | left |
| Slatinný potok | 20.8 | 236.0 | left |
| Lobezský potok | 20.0 | 202.7 | right |

## Use

The Ohře is primarily used for irrigation and hydroelectric energy. There are two reservoirs: Skalka (built in 1962–1964, area 378 ha (930 acres)) and Nechranice (built 1961–1968, area 1,338 ha (3,310 acres)).