Al Wahda Dam, formerly known as M'Jaara Dam, is an

embankment dam An embankment dam is a large artificial dam. It is typically created by the placement and compaction of a complex semi-plastic mound of various compositions of soil or rock. It has a semi-pervious waterproof natural covering for its surface and ...

on the Ouergha River near M´Jaara in

Taounate Province Taounate ( ar, تاونات) is a province in the Fès-Meknès region. It is situated in northern Morocco, north-east of Fes. It had a population of 668,232 in the 2004 Census. Largest towns *Taounate (32,380 inhabitants) * Bouhouda (26,124) *Tamed ...

Morocco Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to ...

. It was constructed 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 ...

irrigation Irrigation (also referred to as watering) is the practice of applying controlled amounts of water to land to help grow Crop, crops, Landscape plant, landscape plants, and Lawn, lawns. Irrigation has been a key aspect of agriculture for over 5,00 ...

water supply Water supply is the provision of water by public utilities, commercial organisations, community endeavors or by individuals, usually via a system of pumps and pipes. Public water supply systems are crucial to properly functioning societies. Thes ...

and

hydroelectric Hydroelectricity, or hydroelectric power, is electricity generated from hydropower (water power). Hydropower supplies one sixth of the world's electricity, almost 4500 TWh in 2020, which is more than all other renewable sources combined and ...

power production. It is the second largest dam in Africa and the largest in Morocco. It was described by Land Ocean Interactions in the Coastal Zone (LOICZ) as "the second most important dam in Africa after the High Aswan dam."

Background

In 1988, the Board of Water and Climate considered the dam and eventually it was recommended for development. Construction began in 1991, the dam began to create its reservoir in 1996 and was inaugurated on March 20, 1997, by

King Hassan II Hassan II ( ar, الحسن الثاني, translit=al-Ḥasan aṯ-ṯhānī;), with the prefix "Mulay" before his enthronement 9 July 1929 – 23 July 1999) was the List of rulers of Morocco, King of Morocco from 1961 until his death in 1999. H ...

. A total of of material were excavated during construction.

Specifications

The dam is an earthen embankment type made of of material and of concrete. It is tall at its highest point and the main portion of the dam is long. Directly to the north and adjacent to the spillway is a saddle dam that is long and high. The dam's

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 tha ...

, in its center is controlled by six

floodgate Floodgates, also called stop gates, are adjustable gates used to control water flow in flood barriers, reservoir, river, stream, or levee systems. They may be designed to set spillway crest heights in dams, to adjust flow rates in sluices and c ...

s and has a discharge capacity in excess of .

Power plant

The power plant, at the dam's toe and adjacent to the spillway is supplied with water via a diameter and long pipe which in turn transfers the water into three

penstocks A penstock is a sluice or gate or intake structure that controls water flow, or an enclosed pipe that delivers water to hydro turbines and sewerage systems. The term is inherited from the earlier technology of mill ponds and watermills. Hyd ...

. Each of which is in diameter in length. This scheme provides of

hydraulic head Hydraulic head or piezometric head is a specific measurement of liquid pressure above a vertical datum., 410 pages. See pp. 43–44., 650 pages. See p. 22. It is usually measured as a liquid surface elevation, expressed in units of length, ...

and up to to the

Francis turbine The Francis turbine is a type of water turbine. It is an inward-flow reaction turbine that combines radial and axial flow concepts. Francis turbines are the most common water turbine in use today, and can achieve over 95% efficiency. The proces ...

s. Each turbine powers an

generator Generator may refer to: * Signal generator, electronic devices that generate repeating or non-repeating electronic signals * Electric generator, a device that converts mechanical energy to electrical energy. * Generator (circuit theory), an eleme ...

for a total installed capacity of .

Impacts

The dam has had a positive impact downstream by supplying water for drinking and

. In addition, it has helped reduce floods in the Gharb region along the Ouergha and

Sebou River Sebou (Berber language, Berber: Asif en Sbu, ar, سبو) is a river in northern Morocco. At its source in the Middle Atlas mountains it is known as the Guigou River (Berber: Asif n Gigu). The river is 496 kilometers long and has an average wat ...

s by 90%. It provides water for the potential irrigation of over . Electricity produced by the dam's hydroelectric power station also alleviates the burning of of fossil fuels a year along with serving peak energy demand. The dam's reservoir though has a high rate of

siltation Siltation, is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary or ...

and it is estimated to lose of storage each year. The silt trapped in the reservoir also doesn't reach the coastal estuary which increases erosion along the coast.

References

{{Reflist Dams completed in 1997 Energy infrastructure completed in 1998 Hydroelectric power stations in Morocco Dams in Morocco Earth-filled dams

Background

Specifications

Power plant

Impacts

See also

References