Weserwehr, Navigation lock in Hemelingen, Germany

Weserwehr is a lock and weir facility on the Weser River in Hemelingen that manages water flow and supports inland shipping traffic. The installation combines multiple chambers and control structures that work together to maintain navigable conditions for commercial vessels.

Built between 1906 and 1911, this facility created artificial boundaries for tidal currents to improve river navigation for commercial traffic. The structure represented a major step in developing the Weser as a reliable inland shipping route.

The weir's name is used locally for the whole barrage, and the adjacent fish pass, built after the new weir opened in 1993, lets fish migrate past the structure. A second fish pass was added with the Weserkraftwerk on the right bank. The weir's operating bridge connects to the lock bridges, so walkers and cyclists cross the entire barrage.

The facility is easily visible from elevated viewpoints, and there are areas where you can observe the lock system in operation. Visiting is possible year-round, though the level of activity varies depending on river traffic.

The weir's five 30-metre-wide fields can each be sealed with emergency closures and pumped dry for maintenance. A walkway bridge about five metres above the upper water connects to the lock bridges, so pedestrians and cyclists can cross the whole barrage. The old 1911 weir was only designed for 2,300 m³/s; the new one handles 3,400 m³/s.