The Czech Republic has three river basins:
The Labe (Elbe) River Basin (drains into the North Sea) - 51,399 sq.km. Main rivers: Labe, Vltava
The Odra (Oder) River Basin (drains into the Baltic) - 4,721 sq.km. Main rivers: Odra, Opava, Ostravice and Olše
The Dunaj (Danube) River Basin (drains into the Black Sea) - 22,744 sq. km. Main rivers: Morava, Dyje
The river basins intersect at Kralický Sni3ník on the Polish border.
Lakes and ponds
There are 455 natural lakes in the Czech Republic, 350 of which are river lakes that have formed in the grasslands of larger rivers.
A characteristic feature of the Czech landscape is the large number of artificial lakes created for fish-farming.
They number 21,800 in total and cover about 41,000 hectares. The largest of them are Lake Rozmberk and Lake Bezdrev in southern Bohemia.
The abundance and quality of mineral springs in the Czech Republic makes the country a world leader in this area.
Many large and renowned spas have been founded around natural or drilled mineral water springs, including the spa in Karlovy Vary, as well as in Mariánské Lázne, Františkovy Lázne, Podebrady, Luhacovice, Jáchymov, and many others which are smaller but still therapeutically important.
The warmest Czech springs include the famous Thermal Spring in Karlovy Vary (72oC), and springs in Teplice (42oC) and Janské Lázni (29.6oC).
The waters from former uranium mines in Jáchymov have the highest radioactivity in the world (5,085 Mach units, .08 oz.Rn/gal.)