A structure called a retention tank—also called a detention tank or retention basin—is used to manage and hold off stormwater runoff. It is a component of stormwater management systems that regulate water flow, prevent flooding, and reduce the likelihood of erosion and water pollution. In metropolitan locations where impermeable surfaces such as buildings and roads hinder the natural absorption of rainfall, retention tanks are frequently utilized. A structure called a retention tank—also called a detention tank or retention basin—is used to manage and hold off stormwater runoff. It is a component of stormwater management systems that regulate water flow, prevent flooding, and reduce the likelihood of erosion and water pollution. In metropolitan locations where impermeable surfaces such as buildings and roads hinder the natural absorption of rainfall, retention tanks are frequently utilized.