The urban area is for the most part paved by roads, parking lots, squares, buildings and paved gardens. As a result, the rainwater in the city can only be absorbed by the subsoil to a limited extent. Usually rainwater is drained through the sewer, so that it disappears from the view of the city dweller. But during heavy showers, the sewer system or the treatment plant can become overloaded and cause nuisance.
Header image: Wikimedia Commons - amsterdam
Icon image: Wikimedia Commons - amsterdam