Intense cloudbursts and abnormally heavy rains are one consequence of climate change, and they pose a major challenge to existing water infrastructure. In the city of Aarhus, Denmark, some parts of the underground sewage system didn’t have the pipe capacity to handle these increasingly frequent water events. This resulted in untreated wastewater and rainwater overflowing into lakes, streams, and the Bay of Aarhus. 


In the Risvangen and Vorrevangen neighborhoods in the northern part of Aarhus, planners choose to deal with the increasing amount of rainwater by keeping it on the surface for recreational use instead of relying on an underproportioned and unscalable pipe system to transport it away. 


In the two neighborhoods, rainwater is now retained in a system of 21 storm water basins. The basins are designed as rainwater lakes with paths, benches, and fauna, where 100 trees have been planted and roadbeds and water channels established. 

On Risvangs Allé, the main road in the area, a central reserve has been transformed into a large green area with paths, tables, benches, a ball field, and outdoor fitness equipment. In some areas, multiple use has been designed in – for instance, a football pitch can serve as a catchment basin in case of cloudbursts. 

This all means that the increasing amount of rainwater can be delayed, evaporated, or diverted at a pace that the creek running through the downstream Risskov woods can handle. 


The advantages have been twofold. First, managing rainwater from the increasingly frequent precipitation events on the surface is economically comparable to establishing underground pipe solutions. Second, surface water has added environmental and recreational value to the area, improving the quality of life and livability of the neighborhoods.


The project was completed in 2019 as a cooperation between the Municipality of Aarhus and Aarhus Vand, a local public water utility.