Flood wall

A floodwall is a freestanding, permanent, engineered structure designed to prevent encroachment of floodwaters.

[1] Floodwalls are mainly used on locations where space is scarce, such as cities or where building levees or dikes (dykes) would interfere with other interests, such as existing buildings, historical architecture or commercial use of embankments.

[clarification needed] Floodwalls are nowadays mainly constructed from pre-fabricated concrete elements.

Floodwalls often have coupures, which are large openings to provide passage of traffic except during periods of flooding, when they are closed.

The substantial costs of floodwalls can be justified by the value of commercial property thus protected from damage caused by flooding.