Which type of dam uses a curved shape to withstand water pressure?

An arch dam is designed with a curved shape that effectively transfers the pressure of the water to the canyon walls or the ground beneath it. This characteristic allows the dam to withstand large amounts of water pressure using less concrete compared to other dam types. The curvature of the dam helps distribute the stresses caused by the water behind it in a way that enhances its stability and structural integrity. When water pressure pushes against the dam, the arch shape means that forces are directed towards the sides, which can be stronger than the pressures pushing straight forward on a flat structure.

In contrast, other dam types, such as embankment dams, rely on weight and mass to resist water pressure, while gravity dams are designed to resist horizontal forces purely through their weight. Roller-compacted dams are built using a different construction method and are not inherently designed around a curved shape to handle water pressure. Therefore, the arch dam's unique design is what makes it particularly efficient in managing water pressure in suitable geological contexts.