What is the purpose of a detention basin?

The primary purpose of a detention basin is to temporarily store storm runoff. These basins are designed to collect excess rainwater and allow it to gradually drain out at a controlled rate. This helps to mitigate flooding, protect downstream waterways from sudden surges of water, and manage stormwater flow during and immediately after rain events. By temporarily holding water, detention basins assist in reducing the peak flow rates that can lead to erosion and other negative impacts on the surrounding environment.

While detention basins can contribute indirectly to improving water quality by allowing sediment and pollutants to settle before the water is released, their primary function is focused on the temporary storage aspect. The other options, such as permanent storage or providing recreational space, are not the main characteristics of detention basins, which are specifically engineered for controlling storm runoff dynamics.