The Magdeburg Water Bridge in Germany deserve special mention. Opened in October 2003 and part of the Magdeburg crossing of waterways, it connects the Elbe-Havel Canal to the Mittellandkanal, crossing over the Elbe River. At 918 meters, it's the longest navigable aqueduct in the world.
The Elbe–Havel Canal and Mittelland Canal canals had previously met near Magdeburg but on opposite sides of the Elbe, which was at a significantly lower elevation than the two canals. Ships moving between the two had to make a 12-kilometre detour, descending from the Mittelland Canal through the Rothensee boat lift into the Elbe, then sailing downstream on the river, before ascending to the Elbe-Havel Canal through Niegripp lock. Low water levels in the Elbe often prevented fully laden canal barges from making this crossing, requiring time-consuming off-loading of cargo.
The reunification of Germany and establishment of major water transport routes made the Water Bridge a priority again. Work started in 1997, with construction taking six years and costing €500 million. The water bridge now connects Berlin’s inland harbour network with the ports along the Rhine river.