After the end of World War II, the growth of transport by inland waterways in Europe, coordinated by the various international authorities, resulted in an enlarged and integrated network brought up to a minimum common standard for craft of 1,350 tons. With the Rhine, the Moselle, and their tributaries dominating the German system and providing outlets for the Dutch and Belgian systems and connecting with the French network, main improvements were concentrated on the international Main-Danube Canal and on improving the north-south route of the Nord-Sud Canal (or Elbe-Seitenkanal). The latter canal (completed in 1976) leaves the Elbe about 32 km (20 miles) above Hamburg and, running south, joins the Mittelland Canal near Wolfsburg, Germany, reaching a total of 115 km (71.5 miles) and shortening the route between Hamburg and the Ruhr by 216 km (134 miles).

The Main-Danube waterway connecting the Rhine with the Black Sea was completed in 1992 and provides a route for traffic between eastern and western Europe through Germany, accommodating craft of 1,350 tons throughout its length. Following the Main River to Bamberg in Germany, the route proceeds by artificial waterway, including a section of the Regnitz Canal to Dietfurt, thence by the Altmühl River to a point below Kelheim, where it joins with the Danube, crossing the Austrian border at Jochenstein. The 71-km (44-mile) Bamberg-to-Nürnberg canal section, completed in 1972, includes seven locks with a combined lift of 82 metres (268 feet). All locks are 190 metres (623 feet) long and able to accommodate vessels of 1,500 tons. Improvements of the channel of the German Danube, begun in 1965, include a pair of locks at Kachlet, just above Passau. In Austria four pairs of locks to take 1,350-ton craft have been built.

The damming of the Danube at Ðerdap (1970–72), the Iron Gate rapids, on the border between Serbia and Romania, was undertaken in conjunction with the improvement of navigation through these dangerous waters; it incorporates vast hydroelectric power plants. Two locks, with two chambers each, were built to facilitate passage through the Iron Gate. Journey time for ships traveling from Black Sea ports upstream to Belgrade, Vienna, and central Europe were reduced from approximately 100 to 15 hours by this project.

France’s waterway network of nearly 8,050 km (5,000 miles) is based primarily on its rivers, but many of the low-capacity canals are being raised to the 1,350-ton standard. A major development in the 1970s in cooperation with West Germany was the construction to this standard of the North Sea–Mediterranean waterway via the canalized Rhône and Rhine rivers. With four existing locks built for the Grand Canal d’Alsace, a projected lateral canal between Huningue and Strasbourg, the project was modified in 1956, and the four remaining dams were built on the Rhine itself and bypassed with short canals including four locks, three with two chambers each. Canalization of the Rhône started with the building of the Port of Edouard-Herriot downstream from Lyon, and work proceeded on 12 locks and dams. Two new ports, serving Valence and Montélimar, were constructed. Improvements were also made on the Marne-Rhine waterway, which provides an important internal trade route connecting the Paris Basin with the industrial regions of Alsace-Lorraine. The improvements included major works on either side of the Vosges summit level, replacing 23 old locks. At Réchicourt a new lock with a lift of 10 metres (32.5 feet) bypasses six locks and a winding section of the old canal; on the other side of the summit a new canal section bypasses 17 locks, which formerly required 8 to 12 hours to navigate. On this section the inclined plane of Saint-Louis-Arzviller deals with a difference in level of 44.5 metres (146 feet) with a horizontal length of 129 metres (422 feet). Two tanks each carry a 350-ton barge. Their 32 wheels run on four rails, and two sets of 14 cables connect the tanks to the two concrete counterweights. Improvements have been made to routes connecting the Seine with the north and east. The Canal du Nord was completed in 1965, and a bottleneck was removed on the Oise Lateral Canal with the building of two locks to accommodate through convoys to Paris.

In the Netherlands the extensive canal system based on large natural rivers and serving the ports of Rotterdam and Amsterdam has required comparatively little modernization, but, to avoid the Maas (Meuse) River, between Roermond and Maastricht, the Juliana Canal was built in 1935 and improved after World War II. The Twente Canal, opened in 1936, improved communication with the industrial east. Most important of the postwar projects was the building of the Amsterdam-Rhine Canal to enhance the capital’s value as a transshipment port. The Noord-Hollandsch Canal from Amsterdam to Den Helder was constructed, and the IJsselmeer was linked with the Ems estuary across the north of Holland. To shorten the distance between Rotterdam and Antwerp by 40 km (25 miles), the Schelde-Rhine Canal was built.

Italy’s waterway system, based on the Po River valley, is cut off from the European network by the Alps but has also been brought up to higher standards.

In Scandinavia there are two major commercial artificial waterways: the first, the Trollhätte Canal, connects the Göta River upward from Göteborg with Lake Vänern and with the Finnish lakes and connecting canals; the second, the Saimaa Canal, in southeast Finland, connecting the vast Saimaa Lake system to the sea, was being reconstructed at the time of World War II. After the Soviet-Finnish War, part was ceded to the Soviet Union, but in 1963 it was leased back to Finland, modernization continued, and the canal, with eight large locks replacing the previous 28, was reopened in 1968.

Water navigation played a major role in the economy of the Soviet Union throughout that country’s existence (1917/22–1991). Its great rivers—the Dnepr, Dvina, Don, Vistula, and Volga—were linked to form an extensive network, making through navigation possible from the Baltic to both the Black Sea and the Caspian Sea. The Black Sea and the Baltic are connected by three different systems, of which the most important is the link between the Dnepr and the Bug, a tributary of the Vistula, by way of the Pripet and Pina rivers, a 204-km (127-mile) canal connecting with the Mukhavets River, a tributary of the western Bug. This system is the sole wholly inland waterway connection to the Caspian and Black seas. When both the Rhine-Danube and Oder-Danube canals are completed, a second route will be provided, via the Berezina River, a tributary of the Dnepr, the Viliya, a tributary of the Niemen, and a 21-km (13-mile) canal, through Latvia to Riga. The last link reaches the Baltic through Lithuania and Poland from the Dnepr by way of the Szara, a tributary of the Niemen; the Jasiolda, a tributary of the Pripet; and a 55-km (34-mile) canal. Other important links are the Volga-Don Canal, 101 km (63 miles) long, completed in 1952, and the Moscow-Volga Canal, built between 1932 and 1937, which flows 129 km (80 miles) from the Volga to the Moscow River at Moscow. The White Sea–Baltic Canal, built in 1931–33, runs from Belomorsk, Russia, on the White Sea, through the canalized Vyg River across Lake Vyg and through a short canal to Povenets at the northern end of Lake Onega, through which it passes to the canalized Svir River, Lake Ladoga, and the Neva River to the southern terminal at St. Petersburg. The total length of the system is 225 km (140 miles), reducing sea passage between St. Petersburg and Arkhangelsk, Russia, by 3,862 km (2,400 miles); through its 19 locks it rises to 102 km (335 feet) above sea level. Elsewhere in former Soviet territory the Ob and Yenisey rivers in Siberia are connected by canal, and the Karakum Canal has been built from Kerki, Turkmenistan, on the Amu Darya, to the Caspian Sea..