The Magdeburg Water Bridge is a navigable aqueduct in Germany that connects the Elbe-Havel Canal to the Mittelland Canal, crossing over the Elbe River. Open in October 2003, this bridge is the longest navigable aqueduct in the world, with a total length of 3,012 feet.
The Elbe-Havel and Mittelland 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 (7.5 mi) detour, descending from the Mittelland Canal through the Rothensee boat lift into the Elbe, then sailing downstream on the river, before ascending up 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.
In addition to the bridge, a double lock was constructed to allow vessels to descend from the level of the bridge and Mittelland Canal to that of the Elbe-Havel Canal.
Additionally a single lock was constructed at Rothensee to allow vessels to descend from the bridge level to the Elbe and the Magdeburg harbour. This lock is parallel to, and replaces the Rothensee boat lift, and can accommodate larger vessels than the lift.