Mže
The Mže is a river in the Czech Republic and shortly in Germany. It flows through Bavaria in Germany and through the Plzeň and Central Bohemian regions. It is the upper course of the Berounka, but usually is considered a separate river. Until its confluence with the Radbuza in Plzeň, when it further continues as Berounka, the Mže is long.
Etymology
According to one theory, the name is of Slavic origin and is derived from the verb mžít. According to the second theory, the name is of Germanic origin and is connected with the root mighia. There is also a theory that the name is of Celtic origin, derived from the word mŏsā and related to the names of the rivers Mieß, Maas and Mosel.Originally, the entire stream including the Berounka was called Mže and the name first appeared in the 12th century in Chronica Boemorum. The name was written as Mse, Msa and Mzye.
From the 17th century, the lower course started to be named Berounka, but the name Mže still appeared as a name for the entire stream at the end of the 19th century. In order to avoid confusion, an initiative was created in 2008 to rename the lower course back to the historical name Mže, but it was unsuccessful due to the strongly adopted current name.
Characteristic
From a water management point of view, the Berounka and Mže are two different rivers with separate numbering of river kilometres. The Mže originates in the territory of Mähring in the Upper Palatine Forest at an elevation of, forms the state boundary for a short distance of and then flows to Plzeň, where it merges with the Radbuza River at an elevation of and continues as Berounka. It is long, of which is in Germany. In the Czech Republic, it is long, which would make it one of the 25 longest rivers in the country, even if taken separately from the Berounka. Its drainage basin has an area of, of which is in the Czech Republic.The longest tributaries of the Mže are:
| Tributary | Length | River km | Side |
| Kosový potok | 46.4 | 67.3 | left |
| Úhlavka | 41.4 | 44.5 | right |
| Úterský potok | 35.8 | 31.3 | left |
| Hamerský potok / Hammerbach | 33.8 | 75.5 | left |
| Vejprnický potok | 23.2 | 2.5 | right |
| Sedlišťský potok | 20.8 | 80.7 | right |
| Žebrácký potok | 13.8 | 27.2 | left |