Emscher System
The beginning of the 19th century saw the start of the redesign of the Emscher and its tributaries as "disposal outlets" for the waste water coming from the Ruhr. Because of the many places where coal mining had resulted in subsidence, underground conduit systems for the runoff of waste water were not a possible option. Instead, a surface canal was created, with massive dikes to protect the lower-lying surrounding countryside from flooding.
