A new ‘green screen’ has been developed to tackle both issues as well as offer architectural qualities by handling rainwater run-off in vertical evaporation elements. The rimary hydrologic mechanism is evaporation so its carbon footprint is low and space requirements and CO2-onerous soil disposals are reduced. It prevents pollution of the aquatic environment and issues with high groundwater levels are avoided. With its multifunctional design, it also contributes to noise reduction, improved air quality, heat island mitigation, enhanced habitat quality and urban space activation.

The concept was first demonstrated in 2019 with a modular solution in a neighbourhood next to one of Copenhagen’s busiest roads with 45,000 vehicles per day. Here, a 80 m long and 3 m high screen receives rainwater run-off from 240 m2 roof surface. It is dimensioned to handle a 10-year rainfall event – the same as the public sewerage system. The introduction of vertical elements for handling rainwater
run-off opens up a new type of green city structures.