The Emschergenossenschaft was founded in 1899 to remedy the desolate sewage situation in the Ruhr region that had arisen in the previous decades as a result of industrialization and urbanization. By the 1920s, the river and its tributaries had been converted into an open sewer system with sewage treatment plants and pumping stations. This state remained until the early 1990s. The ecological conversion of the Emscher system was finally decided in 1992 and will be largely completed in 2022. At the heart of the project are the underground Emscher sewer, four river treatment plants and the renaturation of the surface waters, which are now free of untreated sewage.

The publication, which is being published on the occasion of the 125th anniversary of the Emschergenossenschaft, is aimed at the general public and traces the most important stages of development since the mid-19th century in an illustrated overview text. The numerous challenges and technical solutions of the Emschergenossenschaft are presented in an understandable way over the course of time and integrated into the political, economic and social framework.

Extensive photo series show the Emscher region from its source to its mouth in the Rhine and illustrate the transformation of the river landscape through a combination of historical and contemporary images. The structure is based on the communities along the river in order to focus on local developments and to highlight the special features of the individual communities and cities.