The Assiut Barrage is a dam on the

Nile River The Nile (also known as the Nile River or River Nile) is a major north-flowing river in northeastern Africa. It flows into the Mediterranean Sea. The Nile is the longest river in Africa. It has historically been considered the longest river i ...

in the city of

Assiut AsyutAlso spelled ''Assiout'' or ''Assiut''. ( ' ) is the capital of the modern Asyut Governorate in Egypt. It was built close to the ancient city of the same name, which is situated nearby. The modern city is located at , while the ancient city i ...

Upper Egypt Upper Egypt ( ', shortened to , , locally: ) is the southern portion of Egypt and is composed of the Nile River valley south of the delta and the 30th parallel North. It thus consists of the entire Nile River valley from Cairo south to Lake N ...

(250 miles to the south of

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 ...

). It was completed in 1903.

Background

It was designed by the famous British engineer Sir William Willcocks who also concurrently designed and built the Aswan Low Dam, the first Nile

reservoir A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of wa ...

, about up-stream. The

dam was constructed between 1898 and 1903, and in conjunction with the reservoir, provided for the diversion of river water into

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 ...

's largest irrigation canal, the Ibrahimiya Canal, during the low water season. The dam was estimated to cost £525,000 but by the time of its completion it actually cost £870,000. The main contractor for the project was the British contractor John Aird & Co.Egypt bond
The project's massive size involved 2,400,000 cubic yards of earthwork, 125,000 cubic yards of concrete, 85,000 cubic yards of masonry, 125,000 cubic yards of pitching and more than 4,000 tons of cast iron pipes. The dam consists of a masonry dam about long extended on both sides by earthen banks, making a total length of about . There are 111 arched openings of span in the masonry dam. They can be closed by steel sluice-gates high. The piers and arches are founded upon a masonry platform wide by thick. This platform is protected on its up-stream and down-stream sides by a continuous and impermeable line of cast iron tongued and grooved sheet-piling with cemented joints. This piling extends into the sand bed of the river to a depth of below the upper surface of the platform and prevents it from being undermined. The river bed is protected against erosion for a width of upstream by a stone paving laid on a puddle clay blanket to check infiltration, and on the downstream side for the same width by a stone paving having an inverted filter bed underneath, so that any springs that may be caused by the water above the sluices shall not carry sand with them from beneath the paving. The piers between the openings have a length of up and down stream and are wide with the exception of every thirtieth pier, which has double this width. The roadway is above the top of the masonry platform. The dam has a maximum height of about , the maximum head of water retained being about . It is constructed of granite, the foundation platform mentioned above being of concrete. A lock long by wide and capable of passing the largest Nile cargo ships and barges was constructed at the dam. The Ibrahimiya head regulator structure, which was built at the same time when the Assiut Barrage was being constructed, was of similar design to the barrage except having only nine 5 m wide sluices, and a 9 m wide lock.

Assiut Barrages Repairs and Upgrades

Between 1934 and 1938 the Egyptian Government carried out extensive remodeling works at the barrage and the Ibrahimiya head regulator, principally extending the piers, grouting, extending the approach slabs and updating the hydro-mechanical equipment. The dam was remodeled in 1938 to increase the permissible head to from the head that was allowed under its original design. In 1956 works were carried out at the Ibrahimiya head regulator as a result of significant scour holes that developed downstream of the structure. Extensions to downstream concrete apron were completed as well as lengthening of the southern lock wall. Some further grouting works and replacement of the lock gates took place in the 1970s. In 1979 a reinforced concrete pedestrian footbridge was constructed on the downstream side of the head regulator. Between 1984 and 1986 a program of cement grouting works was undertaken at the barrage, though there are no records of the head regulator receiving similar treatment. After more than 100 years in service, the civil works have been affected by age and also by tailwater erosion as a consequence of a modified river regime after the construction of the

Aswan High Dam The Aswan Dam, or Aswan High Dam, is one of the world's largest embankment dams, which was built across the Nile in Aswan, Egypt, between 1960 and 1970. When it was completed, it was the tallest earthen dam in the world, surpassing the Chatug ...

The Planned New Dam

Along with the Aswan Low Dam, the Assiut Dam today remains in service as the oldest dam on the Nile in Upper Egypt. The two other old dams (Naga Hamadi and Isna Barrages) were replaced with new dams in the 1990s. Between 2000 and 2005, the Egyptian government commissioned an extended Feasibility Study (FS) financed by the German government to investigate the options of rehabilitation of the existing Assiut Barrage and the Ibrahimiya head regulator against reconstruction of a new barrage with a hydro-power plant. German Consultants financed by the Kreditanstalt für Wiederaufbau (KfW) conducted the study and concluded that a new dam with power generating capabilities would be the most economic option. This new dam would provide an increase in the allowed head, allowing more water discharges into the Ibrahimiya Canal and will improve navigation conditions. The new dam will also include a low head hydropower plant providing about 40 Megawatts. The decision taken upon the results of the feasibility study was to proceed with the project of constructing a new barrage 200-300m downstream of the existing barrage. The proposed dam components are: #Sluiceway: 8 radial gates, 17m wide #Hydropower plant: 4 turbines x 8MW #Additional navigation lock: 120 x 17m chamber #Closure dam: embankment type, 11m high #Rehabilitation of the existing navigation lock; and #Rehabilitation of the existing Ibrahimiya head regulatorEgypt Ministry of Water Resources and Irrigation, ''Invitation for the Pre-qualification Process for the Consulting Services for Final Design and Construction Supervision of the New Assiut Barrage and Hydropower Plant Project'' There is a concern that the new maximum pool level will increase the groundwater levels in Assiut city and in some areas in the upstream. Dealing with this situation, different layouts of the project have been studied in the feasibility study and some mitigation measures have been suggested.

References

{{coord, 27.20292, 31.19021, format=dms, display=title, type:landmark Dams in Egypt Dams on the Nile Barrages (dam) Dams completed in 1903 Masonry dams 1903 establishments in Egypt