What are concrete storm drainage pits in multi-story parking structures called?

In multi-story parking structures, concrete storm drainage pits are referred to as graded drains. These drains are designed to facilitate the collection and removal of surface water runoff, ensuring efficient water drainage and reducing the risk of flooding or water accumulation in parking areas. Graded drains are strategically sloped to direct water towards the drainage system, promoting effective water management.

The term "graded" highlights the sloped design which aids in the flow of water into the drainage system. This feature distinguishes graded drains from other types of drainage solutions, which may not necessarily incorporate a slope or angle, impacting their efficiency in managing stormwater in a vertical space like a multi-story garage.