The Dam of Avolsheim, also nicknamed "Small and large gates", was built in 1682 on the artificial waterway of the Bruche designed by French architect Sébastien Vauban. This channel was used to transport sandstone blocks from the quarries of Soultz-les-Bains and Wolxheim to the city of Strasbourg, during the construction of its citadel. The dam was there to keep the water level high enough to supply the nearby canal. This impressive piece of work, with its gates, supplies the channel in water from the Bruche river. The location has not been chosen by accident since it is here that a small tribute, the Mossig river, flows into the Bruche. When the latter is flooded, a portion of the overflow goes into the river bed of the Mossig. Downstream, both banks of the Bruche are made of flood risk areas such as meadows, called "rieds", which are unbuildable.