What is the function of Detention Storage?

Detention storage functions primarily to temporarily hold stormwater runoff during heavy rainfall events before releasing it at a controlled rate. This process helps to manage peak flow rates into drainage systems, preventing flooding and erosion in downstream areas. The primary goal is to mitigate the impact of sudden increases in water volume, allowing for a more gradual release that aligns better with the existing capacity of the drainage systems or natural water bodies.

While enhancing groundwater recharge, purifying water, and controlling evaporation rates are all relevant to stormwater management and water resources, they are not the core purpose of detention storage. Detention systems are specifically designed to address the immediate need for managing excess runoff and reducing potential flood risks. Hence, the correct answer emphasizes the key role of detention storage in flood control during heavy rainfall.