The earliest known dam is in Jordan named the Jawa Dam. This was gravity dam and was a 9 mt high and 1 mt wide stone wall, which was supported by a 50 mt wide ramp. The structure is dated back to 3000 BC. The word Dam can be traced back to as early as the 11th century. The first known appearance was made in the Middle Dutch era between 1150-1500 CE, in Amsterdam. The other early dams were known to be constructed in Mesopotamia and the Middle East. The dams were used to control the water level in the Tigris and Euphrates rivers that affected the weather of Mesopotamia.
Based on structure and material used, dams are classified as gravity dams, arch dams, barrages, and embarkment dams.
Gravity Dams:
Gravity dams are the dams that holds on to the ground forcefully at its place against the push of the water by virtue of Earth's gravity. The water presses laterally on the dam, tending to overturn the dam; however, the dam's weight counteracts that force, tending to rotate the dam the other way about its toe. Here the designer should ensure that the weight of the dam outweighs the force of water and wins that contest.
Arch dams:
Arch dams are dams that obtain stability by a combination of arch and the gravitational pull. If the upstream face is vertical the entire weight of the dam must be carried to the foundation by gravity and when the upstream face is sloped the distribution is more complicated. While the normal hydrostatic pressure will be distributed, the normal component of the weight of the arch ring may be taken by the arch action.
What are Dams and How to Construct One?
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