The work deals with the issue of roof gardens in order to emphasize the importance of roof gardens in relation to surface drainage. A significant reduction in surface runoff is perceived very positively, thanks to the ability of roof gardens to cool the urban environment during hot summer days. The work solves the drainage rates of the settlement and calculates the difference in the drainage after the design of the roof gardens. Outflow is calculated and interpreted in m³ / 1 m². The work deals with other positive influences of the roof gardens on their surroundings but also on the building itself. It also addresses other mitigation and adaptation measures on climate change.