Some pavement can let water in and keep everything else out. Cities represent a remarkable transformation of the landscape from natural to human-made. One of the most significant changes to the landscape that comes with urbanization is impervious cover. That's anything that prevents rain from soaking into the subsurface: buildings, sidewalks, driveways, and the biggest culprits - streets and parking lots. Impervious cover is a big issue. When you pave paradise to put up a parking lot, you cause a pretty significant disruption to some really important natural processes in a watershed. But, not all cover has to be impervious. Watch this video and the entire Practical Engineering catalog ad-free on Nebula: https://go.nebula.tv/practical-engineering -Patreon: http://patreon.com/PracticalEngineering -Website: http://practical.engineering/ Writing/Editing/Production: Grady Hillhouse Editing and Direction Help: Wesley Crump This video is sponsored by HelloFresh.