– 14th century The development of arch dams throughout history began with the
Romans in the 1st century BC and after several designs and techniques were developed, relative uniformity was achieved in the 20th century. The first known arch dam, the
Glanum Dam, also known as the Vallon de Baume Dam, was built by the Romans in
France and it dates back to the 1st century BC. The dam was about high and in length. Its radius was about , and it consisted of two masonry walls. The Romans built it to supply nearby
Glanum with water. The Monte Novo Dam in
Portugal was another early arch
dam built by the Romans in 300 AD. It was high and long, with a radius of . The curved ends of the dam met with two winged walls that were later supported by two buttresses. The dam also contained two water outlets to drive mills downstream. The earliest known surviving arch dam is the
Iron Gate above
Antioch, which combined the functionalities of a
road bridge, an
aqueduct bridge, a
city wall, and a dam. The Iron Gate still functions as a dam in the present day. The
Dara Dam was another arch dam built by the Romans. The historian
Procopius wrote of its design: "This barrier was not built in a straight line, but was bent into the shape of a crescent, so that the curve, by lying against the current of the river, might be able to offer still more resistance to the force of the stream." introducing the concept of
elasticity during the construction of the
Montsalvens arch dam in Switzerland, thereby improving the dam profile in the vertical direction by using a parabolic arch shape instead of a circular arch shape. in the Caucasus of
Georgia Pensacola Dam, completed in the state of
Oklahoma in 1940, was considered the longest multiple arch dam in the United States. Designed by
W. R. Holway, it has 51 arches. and a maximum height of above the river bed. The total length of the dam and its sections is while the multiple-arch section is long and its combination with the spillway sections measure . Each arch in the dam has a clear span of and each buttress is wide. Arch dam designs would continue to test new limits and designs such as the double- and multiple-curve. Alfred Stucky and the U.S. Bureau of Reclamation developed a method of weight and stress distribution in the 1960s, and arch dam construction in the United States would see its last surge then with dams like the 143-meter double-curved
Morrow Point Dam in Colorado, completed in 1968. By the late 20th century, arch dam design reached a relative uniformity in design around the world. The longest multiple arch with buttress dam in the world is the
Daniel-Johnson Dam in
Quebec,
Canada. It is high and long across its crest. It was completed in 1968 and put in service in 1970.
Pensacola Dam was one of the last multiple arch types built in the United States. Its NRHP application states that this was because three dams of this type failed: (1) Gem Lake Dam,
St. Francis Dam (California),
Lake Hodges Dam (California). None of these failures were inherently caused by the multiple arch design. == Design ==