Concrete detention tanks are much more expensive to construct than stormwater ponds.  Consequently, they are rarely used for stormwater control if space for a pond or wetland is available.  In older developed areas, however, space is usually scarce, and the only place left to install facilities is underground.

Stomwater or combined sewer overflows captured by these facilities is usually conveyed to water pollution control plants for treatment after each rain event.  When the flow volume exceeds the tank capacity, the overflow typically drains directly to receiving waters or is pumped offshore.