Allerwehr Celle

Large weir, view from the stevedore house of the rolling mill towards the Ratsmühle

The Allerwehr Celle in downtown Celle is the end point of a federal waterway developed Aller . It consists of two weirs at a fork in the river above the port of Celle. The slope of the Aller has been used here as a stacking place and for water mills since the Middle Ages. The weir system is operated and maintained by the Lower Saxony State Agency for Water Management, Coastal Protection and Nature Conservation ( NLWKN ).

The Herrenmühle is on the northern weir and the Rathsmühle on the southern weir .

Weir on the Aller-Nordarm with Herrenmühle

1994–96 refurbished roll weir with machine house, new stilling basin and cast toothed sleepers

The weir on the all-north arm consists of a movable roller weir system with a machine house, cottage a weir 1904 as well as two-stage from the solid large overflow weir . The listed roller weir system was built in its current form from 1937 to 1939 on previous structures. From 1994 to 1996, after a basic overhaul of the steel structure of the roller body, damaged steel structures were replaced and connected with hot rivets. The stilling basin was refurbished, the tooth sleepers re-cast. The former drive was replaced by a new technology. The old roller winch from 1937 was exhibited on the right bank of the Aller. The Herrenmühle, founded in 1616, is located on the north bank of the Aller and adjacent to the weir .

Weir on the Aller-Südarm with Rathsmühle

Fish pass at the Rathsmühle

The small two-tier weir is located on the Aller-Südarm. Since the weirs with a concrete base and edging and a drop height of 3 m prevent the migration of aquatic life, a fish pass was built at the weir of the Rathsmühle in Celle in 2012 . In 2014, the opposition criticized that their efficiency had not been adequately checked. In addition, a fish-friendly horizontal screen was installed in connection with a new free-flood system to enable fish to migrate into the underwater.

In the course of the relocation of the principality's residence from Lüneburg to Celle in 1378, a grain mill was built on the Aller . The current four-story Rathsmühle building in neoclassical style dates back to 1899. Up until 2009, several hundred tons of flour were produced here every day for the Swedish crispbread manufacturer Wasa . The city of Celle bought the former Rathsmühle with the water rights after it was closed. A use is being sought for the vacant building, while the hydropower plant in the basement was completely renovated from 2012 to 2013. In the municipal hydropower plant Rathsmühle , around 2.7 million kilowatt hours of electricity are generated annually with the help of three turbines under the management of Stadtwerke Celle.