Water, rivers, lakes

In the Czech Republic, rivers are classified as pluvio-nival and above 800 m above sea level as nival-pluvial. It means that the rainfall and snow are the source of the water in rivers. The rivers with the pluvio-nival regime have a maximum of flow due to the rainfall in spring, the secondary maximum in summer during the period of higher precipitation, the single minimum occurs in autumn. The rivers with nival-pluvial regime have a maximum in spring (March to May) due to the snow melting and minimum at the end of winter. The runoff regime is influenced by the altitude and windward or leeward position of the catchment.

Fig1. Flow diagrams of four main rivers. Spring flow maximum is abundant.

All the Czech streams are perennial, which means that the river has constant stream throughout the year through parts of its stream bed during years of normal rainfall. The perennial streams flows continuously.

The density of the river network is higher in the mountains, on the contrary the low density is in the flat lowland areas in Central Bohemia where is the porous bedrock and higher infiltration of the rainfall. The dendritic river network pattern is dominant.

Fig. 2. River network in the Central Bohemia. Areas of very low network density are visible.

Czech rivers are important sources for public water supply system  and industry. Nevertheless the highest abstraction of surface water is made by the energy sector. That water is used mainly for once-through or circulation cooling of steam turbines. There is also more than 600 km of navigable rivers and channels.

Fig. 3. Boaters. Many of Czech rivers are a frequented tourist destination. Almost every Czech sailed a river on a boat once in his life. The most popular rivers are Vltava, Ohře, Lužnice, Berounka or Morava.