More and more towns break open culverts to reveal hidden rivers in the heart of the city, such as Freiburg im Breisgau did already in the 70ies en more recently London and Zurich. According to the World Economic Forum (WEF) the reasons to uncover hidden rivers are the “social, environmental and economic benefits” like “public desire to recapture lost spaces and improve quality of life in the city”. The economic advantage of having clean water flowing through the city instead of jamming sewage works is the reduction of wastewater treatment costs.
The 2005 Cheonggyecheon stream project in Seoul is an almost 11km-long artificial water corridor that diverts water from an underground river, that is a flood relief channel and touristic attraction. In addition, the WEF states that these daylighted waterways can help cool cities and reduce the Urban Heat Island effect, and bring benefits for urban wildlife. In the Dutch city of Apeldoorn the urban stream of the Grift has been daylighted successively from 2002 and the inner city segment will be finalized in 2020 as last piece.
Read more in an article of the WEF and see the detailed plans of Apeldoorn (Dutch only).