Urban drainage refers to the system designed to manage rainwater and surface water in cities. It includes a network of drains, sewers, and culverts that collect and transport excess water away from streets and buildings to prevent flooding and waterlogging. Proper urban drainage is essential for maintaining public safety and protecting infrastructure. Effective urban drainage systems also help improve water quality by filtering pollutants before they reach natural water bodies. They can include features like retention ponds and green roofs that absorb rainwater, reducing runoff and promoting sustainable water management in urban areas.