The dam
The Genale Dam should be remembered not so much for the intrinsic importance (though fairly innovative by the 1920s, being built with reinforced concrete) but especially for the difficulties in the realization and for the great improvements for the social and economic life of the area. The dam also improved the image of colonial Italy in the world. [2]
Reinforced concrete (RC) (also called reinforced cement concrete or RCC) is a composite material in which concrete's relatively low tensile strength and ductility are counteracted by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars (rebar) and is usually embedded passively in the concrete before the concrete sets. Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made of steel, polymers or alternate composite material in conjunction with rebar or not. Reinforced concrete may also be permanently stressed, so as to improve the behaviour of the final structure under working loads. In the United States, the most common methods of doing this are known as pre-tensioning and post-tensioning.
Regarding the construction difficulties, the following are only the most significant among those who had to overcome the Italian builders according to Gaetano De Angelis: [3]
- The weather was inclement with frequent floods of the river, which naturally slowed the process and forced to work often 24 hours a day and with artificial light rather poor.
- The foundation ground was muddy and forced to work with the nearly continuous use of pumps.
- There were no cranes, excavators etc.: the work was done with shovels, buckets and especially "man strength". At certain times to remove 40,000 cubic meters of soil worked together more than 1,000 indigenous workers.
- The material necessary to the work came from Mogadishu, mainly for the iron and timber needed. The bulk (crushed stone, cement, sand, etc.) came from Merca (about 14 km away) and because to reach this small town there was the need to bypass interposed moving sand dunes (in the 1920s there were no roads there), transportation was done with "caravans" of camels because the trucks could not be used. So, were required 120,000 transports by camel (or a caravan of 350-400 camels per day for the duration of the work).
Mogadishu, locally known as Xamar or Hamar, is the capital and most populous city of Somalia. Located in the coastal Banadir region on the Somali Sea, the city has served as an important port for millennia. As of 2017, it had a population of 2,425,000 residents. Mogadishu is the nearest foreign mainland city to Seychelles, at a distance of 835 mi (1,344 km) over the Somali Sea.
Construction began in January 1926 and despite the difficulties mentioned, ended in October of the same year. The inauguration took place on October 28, 1926 (anniversary of Fascism in Italy) and was christened by the countess Rina De Vecchi of Val Cismon, to whom the workers made homage of the model of the dam.
Fascism is a form of radical, right-wing, authoritarian ultranationalism, characterized by dictatorial power, forcible suppression of opposition, and strong regimentation of society and of the economy, which came to prominence in early 20th-century Europe. The first fascist movements emerged in Italy during World War I before it spread to other European countries. Opposed to liberalism, Marxism, and anarchism, fascism is placed on the far-right within the traditional left–right spectrum.
Actually for some experts (like Tripodi [4] ) the question arises how it all could get to the end in such a short time and without major incidents: no loss of life happened. Fascist propaganda pinpointed that the dam was done without enhancing the distinction of class or color - although the work was done in very difficult conditions.
Data
The Shebelle ("river of leopards" in Somali), in the area of Genale where the dam was built, flows in a vast plain between 65–70 meters above sea level and is 13.5 km from the Indian Ocean (point of minimum distance, near Merca). Between the plain and the sea, however, there are sand dunes that are partly movable and rise in height up to 100–130 meters above sea level by preventing the river flowing into the Indian Ocean and forcing it to get to the Jubba river: there the Shebelle river flows only in the rainy periods because normally the water disperses before reaching the Jubba, forming swampy areas.
Until a few years before the intervention in this stretch of plain, although composed of fertile land, there were mainly shrubs and bushes of various tree species. Furthermore, mainly along the banks of the river, there were small groups of huts and little land cultivated by the natives.
In periods of peak demand of water for irrigation, the flow of the river was over 100 m3 per second; therefore - if the dam subtracted from that amount the flow rate of 40 m3/s necessary to irrigate 25-30,000 hectares of land, that were supposed to be the area of agricultural concessions - this fact did not let dry the Shebelle river.
The water flow of the river went down below 40 m3/s only during periods when irrigation did not appear necessary (from January to March). For this reason, the dam was not built with the task of accumulation of water but was to serve as a weir or "intake structure" - to send water toward the distribution channels - to a level quota to allow the water to reach the whole area.
The water channeling - for an initial length of 45 km, that later reached 80 km - is separated upstream of the dam, redistributing into two basic channels:
- A first, called "main" channel, with a capacity of 25 m3/s (and a trapezoid section) with an average width of 13.5 m and 3 m deep.
- A second, called "1st secondary", with a capacity of 15 m3/s (and a trapezoid section) with an average width of 8 m and 3 m deep.
The Jubba River is a river in southern Somalia. It begins at the border with Ethiopia, where the Dawa and Ganale Dorya rivers meet, and flows directly south to the Somali Sea, where it empties at the Goobweyn juncture.
Italian Somaliland, sometimes also referred to as Italian Somalia, was a colony of the Kingdom of Italy in present-day northeastern, central and southern Somalia. Ruled in the 19th century by the Somali Majeerteen Sultanate and the Sultanate of Hobyo, the territory was later acquired in the 1880s by Italy through various treaties.
The Shebelle River begins in the highlands of Ethiopia, and then flows southeast into Somalia towards Mogadishu. Near Mogadishu, it turns sharply southwest, where it follows the coast. Below Mogadishu, the river becomes seasonal. During most years, the river dries up near the mouth of the Jubba River, while in seasons of heavy rainfall, the river actually reaches the Jubba and thus the Somali Sea.
Hydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids, principally water and sewage. One feature of these systems is the extensive use of gravity as the motive force to cause the movement of the fluids. This area of civil engineering is intimately related to the design of bridges, dams, channels, canals, and levees, and to both sanitary and environmental engineering.
Lake Iseo or Iseo lake or Sebino [seˈbiːno] is the fourth largest lake in Lombardy, Italy, fed by the Oglio river.
The Catholic Church in Somalia is part of the worldwide Catholic Church, under the spiritual leadership of the Pope in Rome.
Millerton Lake is an artificial lake near the town of Friant about 15 mi (24 km) north of downtown Fresno. The reservoir was created by the construction of 319 ft high Friant Dam on the San Joaquin River which, with the lake, serves as much of the county line between Fresno County to the south and Madera County to the north.
The Ajuran Sultanate, also spelled Ajuuraan Sultanate, and often simply as Ajuran, was a Somali empire in the medieval times that dominated the Indian Ocean trade. They belonged to the Somali Muslim sultanate that ruled over large parts of the Horn of Africa in the Middle Ages. Through a strong centralized administration and an aggressive military stance towards invaders, the Ajuran Sultanate successfully resisted an Oromo invasion from the west and a Portuguese incursion from the east during the Gaal Madow and the Ajuran-Portuguese wars. Trading routes dating from the ancient and early medieval periods of Somali maritime enterprise were strengthened or re-established, and foreign trade and commerce in the coastal provinces flourished with ships sailing to and coming from many kingdoms and empires in East Asia, South Asia, Southeast Asia, Europe, Middle East, North Africa and East Africa.
Economic history of Somalia is related to the development of Somalia's economy in the last two centuries.
Christianity is a minority religion in Muslim-majority Somalia, with an estimated 10,000 practitioners in a population of over eight million inhabitants. Most Christian adherents come from the Bantu ethnic minority group, or are descended from Italian colonists and belong to the Evangelical and Wesleyan Church of the Nazarene. There is one Catholic diocese for the entire country, the Diocese of Mogadishu.
The Bimaal or Bimal, official name: Jamal, is one of the sub-clans of the major Dir clan family. This clan is widely known for leading a resistance against the colonials in southern Somalia for decades which can be compared to the war of the Sayyid in northern Somalia. The Biimaal mainly lives in Southern Somalia, the Somali region of Ethiopia, which their Gaadsen sub-clan mainly inhabits and in the NEP region of Kenya.
The Ganale Doria River is a perennial river in southeastern Ethiopia. Rising in the mountains east of Aleta Wendo, the Ganale flows south and east to join with the Dawa at the border with Somalia to become the Jubba. The river's tributaries include the Welmel, Weyib, Dumale, Doya, Hawas and the Hambala. The Del Verme Falls is a notable feature of its middle course.
Italian Somalis are Somali descendants from Italian colonists, as well as long-term Italian residents in Somalia.
Vittorio Tedesco Zammarano was an explorer and writer.
Janale is a town in the southeastern Lower Shebelle region of Somalia.
The Royal Corps of Somali Colonial Troops was the colonial body of the Royal Italian Army based in Italian Somaliland, in present-day northeastern, central and southern Somalia.
The Port of Merca, also known as Merca Port, is the official seaport of Merca, situated in southeastern Somalia. It is classified as a jetty class port.
Mogadiscio circuit was a car race done in the main streets of Mogadiscio, that was created in 1938 Italian Somalia.
Vittorio di Africa was a small town in southern Italian Somalia, created by Italian colonists in the late 1920s near the southern Shebelle river.
Genale is a town founded by Italian colonists in the southeastern Lower Shebelle region of Italian Somalia. Actually it is called Janaale..
