Sadd el-Kafara

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Coordinates: 29 ° 47 ′ 43.9 "  N , 31 ° 25 ′ 55.3"  E

Map: Egypt
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Sadd el-Kafara​
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Egypt

The Sadd el-Kafara dam ( Arabic سد الكفرة, DMG Sadd al-Kafara  'dam of the heathen') was built between about 2600 and 2500 BC. Built in Wadi Garawi in Egypt . Other data speak from 2950 to 2750 BC. Chr.

The structure was a kind of stone rubble dam with step-shaped stones on the outside and rubble, gravel and rubble inside. Others refer to the structure as a gravity dam because of its up to 24 m thick walls . It was most likely intended to be used to regulate floods and irrigation.

Construction and dimensions

The dimensions of the structure are given differently in different sources. The dam had a height of about 14 m and the length of the dam crest was 113 m, a base length of 81 m, an upper width of 56 m and a lower width of 98 m. The slope inclinations were about 1: 1.7 on the water side and 1: 1.3 on the air side . The storage volume was between 465,000 and 620,000 cubic meters, depending on how high it was and the catchment area had an extension of 185 km².

Remnants of a bottom outlet or a flood relief system are not visible. Either they were in the destroyed part of the dam or they weren't there at all. The dam core consists of rubble, gravel and weathered material, while the embankments are filled with stones on both sides. On the water side, there is also a top layer of limestone blocks that lie on top of the stone fill like a staircase. The construction time is assumed to be 10 to 12 years.

history

The dam was probably built in the 3rd or 4th Dynasty of the Old Kingdom within 10 to 12 years. On the Palermostein under King Snefru for the "year after the 6th time the count" is reported about the construction of a "wall of Upper and Lower Egypt". So it is possible that the Sadd el-Kafara dam is meant. Since the Wadi Garawi is located directly opposite the necropolis of Dahshur on the western bank of the Nile, the dam could have served as a protective barrier for the necropolis. Ceramic finds that were made in its ruins and that were built in the 3rd to 4th dynasty speak in favor of equating the building mentioned in the Palermostein with the dam .

The dam may never have been completed. Since hardly any sediments were found in the reservoir , it is assumed that the dam was destroyed by an extraordinary flood before or shortly after its completion. This led to a flood disaster in the areas downstream of the construction site in the direction of flow, as there was no diversion for this amount of water. The disaster was apparently so great that the dam was not rebuilt. The Egyptians stopped building dams for at least 800 years, maybe thousands of years.

The remains of the dam or the dam on the eastern bank of the Nile near Helwan , 30 km south of Cairo , were rediscovered in 1885 by Georg Schweinfurth (1836–1925) and can now be viewed together with a recognizable breach 46 m wide.

Robert B. Jansen in "Dams from the Beginning" mentions the reign of Khufu (Pharaoh approximately from 2900 to 2877 BC) as a possible construction time . But Khufu is actually Cheops and ruled from 2620 to 2580 BC. Chr.

See also

literature

  • Georg Schweinfurth: An old dam from the pyramid era. Berlin 1906.
  • Norman Smith: A History of Dams. Davies, London 1971.
  • Garbrecht: Historical dams. Wittwer, Stuttgart 1987, ISBN 3-87919-145-X .
  • Wilhelm von Wölfel: canals, bridges and cisterns. In: Structural Engineering. (Special issue). Ernst and Son, 1999.
  • Nicholas J. Schnitter: A History of Dams, The Useful Pyramids. AA Balkema, Rotterdam 1994, ISBN 90-5410-149-0 .

Web links

Individual evidence

  1. ↑ Camel: Kemet. Issue 2/2002, p. 7.
  2. ↑ a b Günther Garbrecht: The oldest dam in the world. Leichtweiß Institute for Hydraulic Engineering , Braunschweig
  3. ^ Günter Dreyer : Wadi Garawi . In: Lexicon of Egyptology. Vol. 6, Harrassowitz Verlag, Wiesbaden 1986, Sp. 1097.