Underground tanks work as retention basins. They can be integrated in the planning process of urban infrastructure in the underground like underground car parks.
Check out the RAINMAN good practice examples:
no good practice example available
- Anneke Bokern (2015): Water squares in Rotterdam, in Topos 90 Resilient Cities and Landscapes, 78-83, URL: http://www.urbanisten.nl/wp/wp-content/uploads/publication_UB_Topos_2015.pdf
Sabine Scharfe, Saxon State Office for Environment, Agriculture and Geology