What is the function of an underdrain in detention facilities?

The function of an underdrain in detention facilities primarily centers around the management of stormwater runoff. An underdrain system is designed to collect and convey excess water from a detention basin, allowing it to efficiently drain away. This drainage helps to manage the water levels within the detention facility, particularly during heavy rainfall events.

In the context of stormwater management, underdrains play a crucial role in filtering out pollutants and sediment from the water. They typically consist of perforated pipes that are placed in gravel or another porous medium, which acts as a natural filter. As stormwater flows through, the underdrain system removes particulates and potentially harmful substances before releasing the water into the surrounding environment or municipal drainage systems.

In summary, the primary purpose of an underdrain is to enhance the quality of the stormwater being discharged by filtering it and managing water levels in the detention facility, making it an essential feature for effective stormwater management.