A dynamically deployable, low visibility pneumatic cofferdam for flood mitigation is disclosed. The cofferdam includes a first planar component, a second planar component, an inflatable hermetic airbag sandwiched therebetween, and connection members attached to the first planar component, a second planar component to form a cofferdam unit. The connection members are adjustable to apply and maintain a desired amount of pressure on the airbag to enable a watertight seal to be formed. The cofferdam units may be sized and designed to sealingly mate adjacent cofferdam units in a variety of configurations to form watertight seals. The cofferdam units may also be sized and designed to attach to seawalls, flood walls, sidewalks, or other infrastructure. When in a deployed state, the height of the cofferdam may be adjusted to a desired height to provide flood mitigation. When in an undeployed state, the cofferdam remains in a substantially flat and unobtrusive position.