The Danube is of great economic importance to the countries that border it, all of which variously use the river for freight transport, the generation of hydroelectricity, industrial and residential water supplies, irrigation, and fishing.
The movement of freight is the most important economic use of the Danube, and such cities as Izmail, Ukraine; Gala?i and Br!ila, Rom.; Ruse, Bulg.; Belgrade, Serb & MonteNgr..; Budapest; Bratislava, Slov.; Vienna; and Regensburg, Ger., are among the major ports.
Since World War II, navigation has been improved by dredging and by the construction of a series of canals, and river traffic has increased considerably. The most important canals - all elements in a continentwide scheme of connecting waterways - include the Danube-Black Sea Canal, which runs from Cernovad!, Rom., to the Black Sea and provides a more direct and easily navigable link, and the Main-Danube Canal, completed in 1992 to link the Danube to the Rhine and thus to the North Sea.
The Danube has been tapped for power, mainly in its upper course. The process, however, has spread downstream. One of the largest hydroelectric projects - the Djerdap High Dam and the Iron Gate power station - was built jointly by former Yugoslavia and Romania. Not only does the project produce hydroelectricity but it also makes navigable what was once one of the most difficult stretches on the river.
Industrial use of Danube waters is made at Vienna, Budapest, Belgrade, and Ruse. The main irrigated areas are along the river in Slovakia, Hungary, Serbia, and Bulgaria. The river, however, has nearly become unfit for irrigation as well as for drinking water because of the tremendous increase in pollutants; pollution has also diminished the once-rich fishing grounds, although some of the fish have moved to side lakes and swamps.