The Akosombo Dam, also known as the Volta Dam, is a hydroelectric dam on the Volta River in southeastern Ghana in the Akosombo gorge and part of the Volta River Authority.[1] The construction of the dam flooded part of the Volta River Basin and led to the subsequent creation of Lake Volta. Lake Volta is the largest man-made lake in the world by surface area. It covers 8,502 square kilometres (3,283sqmi), which is 3.6% of Ghana's land area. With a volume of 148 cubic kilometers, Lake Volta is the world's third largest man-made lake by volume; the largest being Lake Kariba which contains 185 cubic kilometers of water.[2]
The primary purpose of the Akosombo Dam was to provide electricity for the aluminium industry.[3] The Akosombo Dam was called "the largest single investment in the economic development plans of Ghana."[4] The dam is significant for providing the majority of both Togo and Benin's electricity, although the construction of the Adjarala Dam (on Togo's Mono River) hopes to reduce these countries' reliance on imported electricity.[5] The dam's original electrical output was 912 megawatts (1,223,000hp), which was upgraded to 1,020 megawatts (1,370,000hp) in a retrofit project that was completed in 2006.[6]
The flooding that created the Lake Volta reservoir displaced many people and had a significant impact on the local environment,[7] including seismic activity that led to coastal erosion; a changed hydrology caused microclimatic changes with less rain and higher temperatures. The soil surrounding the lake is less fertile than the soil under it, and heavy agricultural use has required the use of fertilizers, which in turn has led to eutrophication, which caused, among others, the explosive growth of an invasive weed that renders water navigation and transportation difficult, and form a habitat for the vectors of water-borne illnesses such as bilharzia, river blindness and malaria. Resettlement of the displaced inhabitants proved complex and in some cases unsuccessful; traditional farming practices disappeared and poverty increased.
Design
The dam was conceived in 1915 by geologist Albert Kitson, but no plans were drawn until the 1940s.[8] The development of the Volta River Basin was proposed in 1949, but because funds were insufficient, the American company Volta Aluminum Company (Valco) lent money to Ghana so that the dam could be constructed. President Kwame Nkrumah adopted the Volta River hydropower project[4] and commissioned Australian architect Kenneth Scott to design a residence for him overlooking the dam.[9]
The dam is 660m (2,170ft) long and 114m (374ft) high, comprising a high rock-fill embankment dam. It has a base width of 366m (1,201ft) and a structural volume of 7,900,000m3 (10,300,000cuyd). The reservoir created by the dam, Lake Volta, has a capacity of 148km3 (120,000,000acre⋅ft) and a surface area of 8,502km2 (3,283sqmi). The lake is 400km (250mi) long. Maximum lake level is 84.73m (278.0ft) and minimum is 73.15m (240.0ft).[10] On the east side of the dam are two adjacent spillways that can discharge about 34,000m3/s (1,200,000cuft/s) of water. Each spillway contains six 11.5-metre (38ft)-wide and 13.7-metre (45ft)-tall steel floodgates.[11][12]
The dam's power plant contains six 170-megawatt (230,000hp)Francis turbines. Each turbine is supplied with water via a 112–116-metre (367–381ft) long and 7.2-metre (24ft) diameter penstock with a maximum of 68.8m (226ft) of hydraulic head afforded.[10]
The final proposal outlined the building of an aluminumsmelter at Tema, a dam constructed at Akosombo to power the smelter, and a network of power lines installed through southern Ghana. The aluminum smelter was expected to eventually provide the revenue necessary for establishing local bauxite mining and refining, which would allow aluminum production without importing foreign alumina. Development of the aluminum industry within Ghana was dependent upon the proposed hydroelectric power.[4] The proposed project's aluminum smelter was overseen by the American company Kaiser Aluminum and is operated by Valco. The smelter received its financial investment from Valco shareholders, with the support of the Export-Import Bank of the United States. However, Valco did not invest without first requiring insurances from Ghana's government, such as company exemptions from taxes on trade and discounted purchases of electricity. The estimated total cost of the project was $258million.[4]
Construction
Akosombo dam with open spillways
In May 1960, the Ghana government called for tenders for construction of the hydroelectric dam. In 1961, an Italian consortium, Impregilo which had just completed the Kariba Dam, won the contract. In 1961, the Volta River Authority (VRA) was established by Ghana's Parliament through the passage of the Volta River Development Act. The VRA's fundamental operations were structured by six Board members and Nkrumah as chairman. The VRA's primary task is to manage the development of the Volta River Basin, which included the construction and supervision of the dam, the power station and the power transmission network. The VRA is responsible for the reservoir impounded by the dam, fishing within the lake, lake transportation and communication, and the welfare of those surrounding the lake.[2]
The dam was built between 1961 and 1965.[10] Its development was undertaken by the Ghanaian government and funded 25% by the International Bank for Reconstruction and Development of the World Bank, the United States, and the United Kingdom.[13] Impreglio carried out the dredging of the river bed and dewatering of the channel, and completed the dam a month earlier than scheduled despite flooding of the Volta River in 1963 which delayed work over three months. Between 1961 and 1966, 28 workers of Impregilo died during the construction of the dam. Memorials in Akosombo township and St. Barbara Catholic Church have been put up in their honor.[citation needed]
The construction of the Akosombo Dam resulted in the flooding of part of the Volta River Basin and its upstream fields, and in the creation of Lake Volta which covers 3.6% of Ghana's total land area.[2] Lake Volta was formed between 1962 and 1966 and necessitated the relocation of about 80,000people, who represented 1% of the population.[14] People of 700villages were relocated into 52resettlement villages two years prior to the dam's completion; the resettlement program was under the direction of the VRA.[2][3][7][15] Two percent of the resettlement population were riparian fishers, and most were subsistence farmers.[3] The Eastern Region of Ghana and the populations incorporated within its districts were most subject to the project's effects.[16]
The dam provides electricity to Ghana and its neighboring West African countries, including Togo and Benin.[16] Initially 20% of Akosombo Dam's electric output (serving 70% of national demand) was provided to Ghanaians in the form of electricity, the remaining 80% was generated for Valco. The Ghana government was compelled, by contract, to pay for over 50% of the cost of Akosombo's construction, but the country was allowed only 20% of the power generated. Some commentators are concerned that this is an example of neocolonialism. In recent years the production from the Valco plant has declined with the vast majority of additional capacity in Akosombo used to service growing domestic demand.[17]
Initially, the dam's power production capabilities greatly overreached the actual demand; while the demand since the dam's inception has resulted in the doubling of hydropower production.[18] Ghana's industrial and economic expansion triggered a higher demand for power, beyond the Akosombo's power plant capabilities. By 1981, a smaller dam was built at Kpong, downstream from Akosombo, and further upgrades to Akosombo have become necessary for maintaining hydropower output.[2]
Increasing demands for power exceed what can be provided by the current infrastructure. Power demands, along with unforeseen environmental trends, have resulted in rolling blackouts and major power outages.[2][18] An overall trend of lower lake levels has been observed, sometimes below the requirement for operation of the dam.[18]
In the beginning of 2007, concerns were expressed over the electricity supply from the dam because of low water levels in the Lake Volta reservoir.[19] During the latter half of 2007, much of this concern was abated when heavy rain fell in the catchment area of Volta River.[20] In 2010, the highest-ever water level was recorded at the dam. This necessitated the opening of the flood gates at a reservoir elevation of 84.45m (277ft), and for several weeks, water was spilled from the lake, causing some flooding downstream.[21]
Impacts
The hydroelectric power plant on Lake Volta
The Akosombo Dam benefited some industrial and economic activities from the addition of lake transportation, increased fishing, new farming activities along the shoreline, and tourism.[7]
In the time following the construction of the dam, there has been a steady decline in agricultural productivity along the lake and the associated tributaries.[7] The land surrounding Lake Volta is not nearly as fertile as the formerly cultivated land residing underneath the lake, and heavy agricultural activity has since exhausted the already inadequate soils. Downstream agricultural systems are losing soil fertility without the periodic floods that brought nutrients to the soil before the natural river flow was halted by the dam.[18] The growth of commercially intensive agriculture has produced a rise in fertilizer run-off into the river. This, along with run-off from nearby cattle stocks and sewage pollution, has caused eutrophication of the river waters.[7] The nutrient enrichment, in combination with the low water movement, has allowed for the invasion of aquatic weeds (Ceratophyllum). These weeds have become a formidable challenge to water navigation and transportation.[2]
Human welfare
The presence of aquatic weed along the lake and within the tributaries has resulted in even greater detriment to local human health. The weeds provide the necessary habitat for black-fly, mosquitoes and snails, which are the vectors of water-borne illnesses such as bilharzia, river blindness and malaria.[7][22] Since the installation of the dam, these diseases have increased remarkably. In particular, resettlement villages have shown an increase in disease prevalence since the establishment of Lake Volta, and a village's likelihood of infection corresponds to its proximity to the lake.[3] Children and fishermen have been especially hard hit by this rise of disease prevalence.[3] Additionally, the degradation of aquatic habitat has resulted in the decline of shrimp and clam populations.[2] The physical health of local communities has been diminished from this loss of shellfish populations, as they provided an essential source of dietary protein. Likewise, the rural and industrial economies have experienced the financial losses associated with the decimation of river aquaculture.[7]
Increased human migration within the area has been driven by poverty and unfavorable resettlement conditions.[7][18] This migration enabled the contraction of HIV and has since led to its heightened prevalence within Volta Basin communities.[16] The districts of Manya Krobo and Yilo Krobo, which lie within the southwest portion of the Volta Basin, are predominantly indigenous communities that have attained a disproportionate prevalence of HIV.[16] The situation underlines the strength of the local factors upon these districts. Commercial sex work was established in response to the thousands of male workers that were in the area for building the dam.[16] Ten percent of the child-bearing females from these two districts migrated out of their districts during this time.[16] In 1986, "90% of AIDS victims in Ghana were women, and 96% of them had recently lived outside the country".[16]
Socioeconomics
The loss of land experienced by the 80,000people forcibly relocated meant the loss of their primary economic activities from fishing and agriculture, loss of their homes, loss of their family grave sites, loss of community stability, and the eventual loss of important social values.[7] The resettlement program demonstrated the social complexities involved in establishing "socially cohesive and integrated" communities.[7] Insufficient planning resulted in the relocation of communities into areas that were not capable of providing for their former livelihoods and traditions.[7] The loss of the naturally fertile soils beneath Lake Volta essentially led to the loss of traditional farming practices.[7] The poor living conditions provided within the resettlement villages has been demonstrated by population reductions since resettlement. One resettlement village in particular experienced a greater than 50% population reduction in the 23 years following relocation.[7] Increased economic risks and experiences of poverty are associated with those communities most impacted by the Volta River's development.[2] The extensive human migration and degradation of natural resources within the Volta-basin area, are the products of poverty in conjunction with population pressure.[18]
Physical environment
Reservoir-induced seismicity has been recorded because of the crustal re-adjustments from the added weight of the water within Lake Volta.[7] There is an eastward shift of the river's mouth from the changes to the river's delta, and this has led to continuing coastal erosion. The changes in the river hydrology have altered the local heat budget which has caused microclimatic changes such as decreasing rain and higher mean monthly temperatures. All of these larger scale environmental impacts will all further compound the problems surrounding disruptions to local economic activities and associated, difficult human welfare conditions.[7] A case study by the International Federation of Surveyors has indicated that the dam has had a significant impact on the shoreline erosion of the barrier separating the Keta Lagoon from the sea. Dr. Isaac Boateng has calculated the reduction of fluvial sediment as being from 71 million cubic metres per year to as little as 7 million cubic metres per year.[23]
Until 2023, the last time Akosombo dam community experienced flooding as a result of controlled spillage of the dam was in 2010.[24]
On September 15th, 2023, the Volta River Authority (VRA) initiated a controlled spillage of water from the Akosombo and Kpong dams situated in the Eastern Region. This controlled spillage led to flooding in communities located along the lower Volta Basin leading to power interruptions. Many victims lost their belongings and livelihood due to the floods.[25] The losses include farmlands, houses and properties which were destroyed by the floods.[26]
Ghana is a West African country in Africa, along the Gulf of Guinea.
The Volta River is the main river system in the West African country of Ghana. It flows south into Ghana from the Bobo-Dioulasso highlands of Burkina Faso. The main parts of the river are the Black Volta, the White Volta, and the Red Volta. In the northwest, the Black Volta forms the international borders between the Ivory Coast, Ghana, and Burkina Faso. The Volta flows southward along the Akwapim-Togoland highlands, and empties into the Atlantic Ocean at the Gulf of Guinea at Ada Foah. One of its smaller tributaries, the Oti River, enters Ghana from Togo in the east. The Volta River has been dammed at Akosombo for generating hydroelectricity. The reservoir named Lake Volta stretches from Akosombo Dam in the south to the northern part of the country, and is the largest man-made reservoir by area in the world.
Lake Nasser is a vast reservoir in southern Egypt and northern Sudan. It was created by the construction of the Aswan High Dam and is one of the largest man-made lakes in the world. Before its creation, the project faced opposition from Sudan as it would encroach on land in the northern part of the country, where many Nubian people lived who would have to be resettled. In the end Sudan's land near the area of Lake Nasser was mostly flooded by the lake. The lake has become an important economic resource in Egypt, improving agriculture and touting robust fishing and tourism industries.
Lake Volta, the largest artificial reservoir in the world based on surface area, is contained behind the Akosombo Dam which generates a substantial amount of Ghana's electricity. It is completely within the country of Ghana and has a surface area of 8,502 square kilometres (3,283 sq mi). It extends from Akosombo in the south to the northern part of the country.
The Eastern Region is located in the Eastern part of Ghana and is one of the sixteen administrative regions of Ghana. Eastern region is bordered to the east by the Lake Volta, to the north by Bono East Region and Ashanti region, to the west by Ashanti region, to the south by Central region and Greater Accra Region. Akans are the dominant inhabitants and natives of Eastern region and Akan, Ewe, Krobo, Hausa and English are the main spoken languages. The capital town of Eastern Region is Koforidua.The Eastern region is the location of the Akosombo dam and the economy of the Eastern region is dominated by its high-capacity electricity generation. Eastern region covers an area of 19,323 square kilometres, which is about 8.1% of Ghana's total landform.
Articles related to Ghana include:
Volta Aluminum Company, known as VALCO, is an aluminium company based in Tema, Greater Accra Region founded by Kaiser Aluminum and now wholly owned by the government of Ghana.
The Volta River Authority (VRA) is the main generator and supplier of electricity in Ghana. They are also responsible for the maintenance of the hydro power supply plant.
The Bui Dam is a 400-megawatt (540,000 hp) hydroelectric project in Ghana. It is built on the Black Volta river at the Bui Gorge, at the southern end of Bui National Park. The project was a collaboration between the government of Ghana and Sino Hydro, a Chinese state-owned construction company. Construction on the main dam began in December 2009. Its first generator was commissioned on 3 May 2013, and the dam was inaugurated in December of the same year.
The Kenney Dam is a rock-fill embankment dam on the Nechako River in northwestern British Columbia, built in the early 1950s. The impoundment of water behind the dam forms the Nechako Reservoir, which is also commonly known as the Ootsa Lake Reservoir. The dam was constructed to power an aluminum smelter in Kitimat, British Columbia by Alcan, although in the late 1980s the company increased their economic activity by selling excess electricity across North America. The development of the dam caused various environmental problems along with the displacement of the Cheslatta T'En First Nation, whose traditional land was flooded.
Industry in Ghana accounts for about 24.5% of total GDP. However, Ghana's industrial production is rising at a 7.8% rate, giving it the 38th fastest growing industrial production in the world due to government industrialization policies.
Ghana generates electric power from hydropower, fossil-fuel, and renewable energy sources such as wind and solar energy. Electricity generation is one of the key factors in order to achieve the development of the Ghanaian national economy, with aggressive and rapid industrialization; Ghana's national electric energy consumption was 265 kilowatt hours per each one in 2009.
The Kpong Dam, also known as the Akuse Dam, is a hydroelectric power generating dam on the lower Volta River near Akuse in Ghana. It is owned and operated by Volta River Authority. It was constructed between 1977 and 1982. Its power station has a capacity of 148 megawatts (198,000 hp) with all four units running, though the total nameplate capacity is 160 megawatts (210,000 hp).
The Ministry of Energy and Petroleum is the ministry in charge of extending and ensuring a continuous supply of energy and petroleum services to every division of the Ghanaian economy in an energy sufficient, environmentally friendly manner.
Dodi Princess was a cruise boat on Lake Volta in South Ghana. It was owned by the Volta River Authority and under the management of Volta Hotels. It was the only cruise ship in Ghana. It was built as a cargo ship and later converted into a passenger ship in 1991.
Samuel Okudzeto Ablakwa is a Ghanaian politician who is a Member of Parliament for North Tongu. He was a deputy minister of state under both John Atta Mills and John Mahama.
Louis Casely-Hayford was a Ghanaian chartered engineer who served as the third CEO of the Volta River Authority (VRA) from 1980 to 1991. He was CEO of the VRA when the master-plan for extension of electricity to the northern parts of Ghana was conceived. He led the creation of the VRA Training School, which trained engineers, technicians and other disciplines needed to support the power sector of Ghana. Casely-Hayford also played monumental roles as CEO in the development of Kpong Power Project.
The Akosombo Dam Spillage Flood is a riverine flood that occurred in the south-eastern part of Ghana. This is due to a controlled spillage of the Akosombo Dam and the Kpong Dam by the Volta River Authority to address rising water levels.
Floods in Ghana refer to a series of flood incidents that have caused property damage and loss of life. Floods are caused by excessive rainfall and dam spillages.
Here is a list of all floods which occurred in Ghana in 2023 across all regions.
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