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 flood ...

10 km southeast of Helwan in Helwan Governorate,

Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a List of transcontinental countries, transcontinental country spanning the North Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via a land bridg ...

. 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 in 1885.

Specifications

The dam 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 w ...

ashlar Ashlar () is finely dressed (cut, worked) stone, either an individual stone that has been worked until squared, or a structure built from such stones. Ashlar is the finest stone masonry unit, generally rectangular cuboid, mentioned by Vitruv ...

s. 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, 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 The Nile, , Bohairic , lg, Kiira , Nobiin: Áman Dawū is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa and has historically been considered the longest riv ...

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.

References

{{reflist Dams in Egypt Archaeological sites in Egypt 3rd-millennium BC architecture

Specifications

Destruction

See also

References