Sadd el-Kafara ("Dam of the Infidels") was a
masonry
Masonry is the building of structures from individual units, which are often laid in and bound together by mortar; the term ''masonry'' can also refer to the units themselves. The common materials of masonry construction are bricks, building ...
embankment dam on
Wadi al-Garawi
Sadd el-Kafara ("Dam of the Infidels") was a masonry embankment dam on Wadi al-Garawi 10 km southeast of Helwan in Helwan Governorate, Egypt. The dam was built in the first half of the third millennium BC by the ancient Egyptians for floo ...
10 km southeast of
Helwan in
Helwan Governorate
Helwan Governorate was one of the governorates of Egypt. It was located in Lower Egypt.
History
The Helwan Governorate was split from the Cairo Governorate in April 2008. It was created through a presidential decree in order to ease the burden ...
,
Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medit ...
. The dam was built in the first half of the third millennium BC by the
ancient Egyptians for
flood control
Flood control methods are used to reduce or prevent the detrimental effects of flood waters."Flood Control", MSN Encarta, 2008 (see below: Further reading). Flood relief methods are used to reduce the effects of flood waters or high water level ...
and is the oldest dam of such size in the world.
Never completed, the dam was under construction for 10–12 years before being destroyed by a flood. It was rediscovered by
Georg Schweinfurth
Georg August Schweinfurth (29 December 1836 – 19 September 1925) was a Baltic German botanist and ethnologist who explored East Central Africa.
Life and explorations
He was born at Riga, Latvia, then part of the Russian Empire. He was edu ...
in 1885.
Specifications
The
dam
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 ...
was not finished but was about 111m long and 14m tall with a base width of 98m and crest width of 56m. The dam's core was 32m wide and consisted of 60,000 tons of earth and rock-fill. Surrounding the core were two loosely filled rubble and rock-fill layer-walls. The downstream wall was about 37m wide, the upstream wall about 29m wide and they encompassed of material. Encasing the dam were upstream and downstream walls created from
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
ashlars. The ashlars were set but not mortared in stepped rows. Each ashlar was roughly high, wide, long and roughly .
Destruction
Because of erosion on the downstream face of the incomplete dam and its lack of a
spillway
A spillway is a structure used to provide the controlled release of water downstream from a dam or levee, typically into the riverbed of the dammed river itself. In the United Kingdom, they may be known as overflow channels. Spillways ensure th ...
, it is believed that a flood destroyed it. In addition, there was no evidence of a trench or tunnel that would have diverted water in the wadi around the construction site. Construction on the upstream side of the dam was mostly complete but the downstream side was much less developed. The crest of the dam sloped towards the center which the engineers may have intended to use as a spillway. However, as the top of the dam was not beheaded it was not protected from flood water that would over-top the crest. The dam's proximity to the fertile
Nile River and distance from populations indicates it was built for protection against such events, similar to those that still occur today.
If complete, the dam would have stored – of water and flooding would have caused the reservoir to flood into adjacent parallel wadis. The dam's failure likely made Egyptian engineers reluctant to construct another for nearly eight centuries.
Another indication that the dam may have been diminished due to flooding, or an overflow, is that the dam, itself, did not contain high quantities of silt, implying that the dam did not last long enough for the river to leave an obvious residual fingerprint on it.
See also
*
Jawa Dam
References
{{reflist
Dams in Egypt
Archaeological sites in Egypt
3rd-millennium BC architecture