The Nussdorf weir and lock are works of hydraulic engineering located in the Viennese suburb of Nussdorf at the point where the Donaukanal leaves the Danube. The weir and lock were built following the adoption of a new law in July 1892, which also authorised the construction of the Vienna Stadtbahn and the transformation of the Donaukanal into a winter harbour.
The weir and lock in Nussdorf are commonly confused with one another, although they are actually two separate constructions built to serve the same purpose.
The weir and lock are located behind the Nussdorf station of the Emperor Franz Joseph Railway. Although they are named after a suburb in the 19th district of Vienna, Döbling, they actually fall within the jurisdiction of the 20th district, Brigittenau.
Before the construction of the weir and lock in Nussdorf, the Donaukanal was protected from floating ice and to a large extent also from flooding by the Wilhelm von Eng