Flood protection walls are used to control, reduce or prevent the deleterious effects of rising water levels. By using concrete interlocking building blocks, an excellent modular flood protection wall can be created. The precast concrete elements are stacked on top of each other and do not require mortar (dry-lay). The blocks have studs and notches that interlock them. Due to their mass and the presence of studs and recesses, they will not move and therefore do not require the use of a bonding material such as mortar. Precast concrete products are widely used to build new dams, construct floodplain protection or raise river banks. These walls can be constructed without special equipment and provide a reliable, economical and easy to erect solution.