page_title: Dam
section_title: Roman engineering
hierarchical_section_title: Dam / History / Roman engineering
caption_attribution_description: English: Roman-built Band-e Kaisar ("Caesar's dam") in Shushtar, Iran, said to have been built by Roman prisoners during the reign of Shapur I (ca. 260−270 AD). The dam bridge, the most eastern Roman engineering structure, was the first of its kind in Iran. Deutsch: Der römische Band-e Kaisar ("Caesars Damm") in Schuschtar (Iran), der laut der persischen Überlieferung unter der Herrschaft von Schapur I. von römischen Kriegsgefangenen errichtet wurde (um 260−270 n. Chr.). Der Brückendamm, der östlichste jemals errichtete römische Ingenieurbau, war der erste seiner Art in Iran.
context_page_description: A dam is a barrier that stops or restricts the flow of 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 water or for storage of 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 earliest known dam is the Jawa Dam in Jordan, dating to 3,000 BC.
  The word dam can be traced back to Middle English, and before that, from Middle Dutch, as seen in the names of many old cities. The first known appearance of dam occurs in 1165. However, there is one village, Obdam, that is already mentioned in 1120. The word seems to be related to the Greek word taphos, meaning "grave" or "grave hill". So the word should be understood as "dike from dug out earth".
context_section_description: Roman dam construction was characterized by "the Romans' ability to plan and organize engineering construction on a grand scale." Roman planners introduced the then-novel concept of large reservoir dams which could secure a permanent water supply for urban settlements over the dry season. Their pioneering use of water-proof hydraulic mortar and particularly Roman concrete allowed for much larger dam structures than previously built, such as the Lake Homs Dam, possibly the largest water barrier to that date, and the Harbaqa Dam, both in Roman Syria. The highest Roman dam was the Subiaco Dam near Rome; its record height of 50 m (160 ft) remained unsurpassed until its accidental destruction in 1305.
  Roman engineers made routine use of ancient standard designs like embankment dams and masonry gravity dams. Apart from that, they displayed a high degree of inventiveness, introducing most of the other basic dam designs which had been unknown until then. These include arch-gravity dams, arch dams, buttress dams and multiple arch buttress dams, all of which were known and employed by the 2nd century AD (see List of Roman dams). Roman workforces also were the first to build dam bridges, such as the Bridge of Valerian in Iran.
  In Iran, bridge dams such as the Band-e Kaisar were used to provide hydropower through water wheels, which often powered water-raising mechanisms. One of the first was the Roman-built dam bridge in Dezful, which could raise water 50 cubits in height for the water supply to all houses in the town. Also diversion dams were known. Milling dams were introduced which the Muslim engineers called the Pul-i-Bulaiti. The first was built at Shustar on the River Karun, Iran, and many of these were later built in other parts of the Islamic world. Water was conducted from the back of the dam through a large pipe to drive a water wheel and watermill. In the 10th century, Al-Muqaddasi described several dams in Persia. He reported that one in Ahwaz was more than 910 m (3,000 ft) long, and that it had many water-wheels raising the water into aqueducts through which it flowed into reservoirs of the city. Another one, the Band-i-Amir dam, provided irrigation for 300 villages.
caption: Remains of the Band-e Kaisar dam, built by the Romans in the 3rd century AD
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