Sadd el-Kafara ("Dam of the Infidels") was a masonry embankment dam on Wadi al-Garawi 10 km southeast of Helwan in

Cairo Cairo ( ; , ) is the Capital city, capital and largest city of Egypt and the Cairo Governorate, being home to more than 10 million people. It is also part of the List of urban agglomerations in Africa, largest urban agglomeration in Africa, L ...

Egypt Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...

. The dam was built in the first half of the third millennium BC by the

ancient Egypt Ancient Egypt () was a cradle of civilization concentrated along the lower reaches of the Nile River in Northeast Africa. It emerged from prehistoric Egypt around 3150BC (according to conventional Egyptian chronology), when Upper and Lower E ...

ians for flood control and is the second oldest dam of the world, after the Marib Dam in Yemen. 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 is a type of carbonate rock, carbonate sedimentary rock which is the main source of the material Lime (material), lime. It is composed mostly of the minerals calcite and aragonite, which are different Polymorphism (materials science) ...

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, 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.

References

{{Authority control Dams in Egypt Archaeological sites in Egypt Buildings and structures completed in the 3rd millennium BC

Specifications

Destruction

See also

References