With climate change, cities are facing more extreme weather events, such as heavy rainfall, heat waves, and droughts 1 . Cities are particularly vulnerable due to their high proportion of sealed surfaces 2 . Pavement reduces the infiltration of rainwater and increases heat stress, which contributes to heat islands and increased risks of flooding 1,3 . The city of Zurich is no exception; an increase in hot days and tropical nights, prolonged dry periods, and heavy rainfall events occasionally overloading the sewage system are forcing the city to rethink its water management 4 . One approach to deal with these challenges is the implementation of the sponge city concept 1 . What is a sponge city? A sponge city is an urban planning concept that aims to minimise surface water runoff. This concept envisions cities reacting similarly to a sponge by enabling local infiltration, storage, and evaporation of water. This not only reduces flooding but also keeps water available du...