As Deutsche Welle described the bridge upon its completion in 2003:
Taking six years to build and costing around half a billion euros, the massive undertaking will connect Berlin's inland harbor with the ports along the Rhine river. At the center of the project is Europe's longest water bridge measuring in just shy of a kilometer at 918 meters. The huge tub to transport ships over the Elbe took 24,000 metric tons of steel and 68,000 cubic meters of concrete to build.
The water bridge will enable river barges to avoid a lengthy and sometimes unreliable passage along the Elbe. Shipping can often come to a halt on the stretch if the river's water mark falls to unacceptably low levels.
Links: www.snopes.com, en.wikipedia.org, ritemail.blogspot.com