An arch dam is a concrete dam that is curved upstream in plan. The arch dam is designed so that the force of the water against it, known as hydrostatic pressure, presses against the arch, causing the arch to straighten slightly and strengthening the structure as it pushes into its foundation or abutments. An arch dam is most suitable for narrow canyons or gorges with steep walls of stable rock to support the structure and stresses. Since they are thinner than any other dam type, they require much less construction material, making them economical and practical in remote areas.
The Katse Dam, a 185 m high concrete arch dam in Lesotho.
The Morrow Point Dam is a double-curvature arch dam.
The Idukki Dam in Kerala, India is a double-curvature arch dam
Shāh Abbās Arch near Kurit Dam – 14th century
A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, aquaculture, and navigability. Hydropower is often used in conjunction with dams to generate electricity. A dam can also be used to collect or store water which can be evenly distributed between locations. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions.
The Edersee Dam in Hesse, Germany
The Roman dam at Cornalvo in Spain has been in use for almost two millennia.
Remains of the Band-e Kaisar dam, built by the Romans in the 3rd century AD
An engraving of the Rideau Canal locks at Bytown