| Two water filled tubes or columns placed side by side will assume their natural shapes. If pressure is applied to one side, the water is displaced in the first tube and causes it to roll. As the first tube rolls, it pushes on the second tube moving the water from one side to the other and the two tubes roll together. |
 | The AquaDam® is able to offer a stable wall by containing two water columns in a single outer tube. The contained water columns are unable to assume their natural position and form a vertical wall in the middle as they press against each other. The pressure inside the tubes applies a substantial force to both sides of this vertical wall. |
 | As water begins to build on one side of the structure the inner tube naturally tries to roll. However, the friction between the vertical walls of the inner tubes and between the inner and outer tubes opposes the rolling tendency and the structure remains fixed. |
