Sustainable urban drainage

Sustainable drainage systems (Suds) are a natural approach to managing drainage in and around properties and other developments. SuDs work by slowing and holding back water that runs off a site (perhaps during heavy rainfall), this allowing time for natural processes to help breakdown some pollutants and helps reduce the risk of flooding

Source of definition

https://www.netregs.org.uk/environmental-topics/water/sustainable-drainage-systems-suds/what-are-sustainable-drainage-systems/