A catch basin is a drainage structure, typically consisting of a grated inlet at street level and an underground chamber, that collects rainwater and snowmelt from roads and directs it into the storm sewer system. The grate allows water to enter while catching larger debris. The chamber below often has a sump that traps sediment before water continues to the storm sewer. Catch basins require periodic cleaning to remove accumulated sediment and debris and ensure proper drainage. Clogged catch basins can cause street flooding during heavy rain. Municipal public works crews maintain catch basins as part of stormwater infrastructure management.