This room contains information about barriers that have temporary and permanent features. It also includes barriers that are permanently installed but have features that become visible and functional only when a flood situation exists.

The majority of the system is mounted or installed in response to an immediate flood threat; that part is temporary. These temporary barrier components rely for strength on components that are permanently installed. The permanent portion may be installed out of sight or be very inconspicuous. In some cases, the permanent portion will be quite visible.The permanent portions of demountable barriers provide the strength or foundation of the system and would follow the design principles applied to permanent barriers: levees and floodwalls.