The legal basis for the renaturation measure is the European Water Framework Directive, which obliges member states to achieve what is known as "good status" for their water bodies. As part of the "Blau Plus" campaign, the state of Rhineland-Palatinate has granted the city of Mainz a 90 percent subsidy for the renaturation of the Aubach, a third-order water body.

A 530-meter section of the Aubach was restored to a largely natural state by removing existing concrete fortifications, flattening steep embankments, and removing existing weirs.

The earthworks and hydraulic engineering work began in October 2024 in the area between "Am Elmerberg" and "Altes Wasserwerk" in Mainz-Finthen and was completed at the end of February 2025. Among other things, concrete channels were removed and flatter bank areas were created as floodplains. On the south side of the Aubach, riverside properties were acquired by the state capital of Mainz in 2018 and used to create widenings, islands, and zones of alternating moisture with appropriate initial planting, i.e., targeted initial planting of native species. This planting and vegetation work, such as the planting of native meadow and softwood species, followed the earthworks and hydraulic engineering work until the beginning of June 2025. 

The renaturation measure was approved by the water authorities on July 31, 2025.