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Akosombo Dam
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The Akosombo Hydroelectric Project (Akosombo HEP), usually referred to as the Akosombo Dam, is a hydroelectric dam in southeastern Ghana. The dam is specifically located at the Akosombo gorge, on the Volta River. The construction of the dam resulted in the flooding of the Volta River Basin, and the subsequent creation of Lake Volta. Lake Volta is the world's largest man-made lake and covers about 3.6% of Ghana's total land area .
The primary purpose of the Akosombo HEP was to provide electricity for the Aluminum Industry .
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Encyclopedia
The Akosombo Hydroelectric Project (Akosombo HEP), usually referred to as the Akosombo Dam, is a hydroelectric dam in southeastern Ghana. The dam is specifically located at the Akosombo gorge, on the Volta River. The construction of the dam resulted in the flooding of the Volta River Basin, and the subsequent creation of Lake Volta. Lake Volta is the world's largest man-made lake and covers about 3.6% of Ghana's total land area .
The primary purpose of the Akosombo HEP was to provide electricity for the Aluminum Industry . The Akosombo HEP was called "the largest single investment in the economic development plans of Ghana" . Its original electrical output was 912 MWe, which was upgraded to 1020 MWe in a retrofit project that was completed in 2006.
The flooding of land to create the Lake Volta reservoir, displaced many people and had a significant impact on the environment .
In the beginning of 2007, there were concerns over the electricity supply from the dam due to lower water levels in the Lake Volta reservoir. Some sources say these are due to problems with drought that are a consequence of global warming. During Q3-Q4 of 2007, much of this concern was abated when heavy rain fell in the catchment area of Volta River.
About
The idea for the dam originated in 1915 with the Geologist Albert Ernest Kitson but it was not until the 1940s that plans for the dam began to be drawn. The dam provides electricity to Ghana and its neighboring West African countries, including Togo and Benin. The dam is 660 Metres wide and 114 Metres high. It cost £130 million to build. It was built between 1961 and 1965. Its development was undertaken by the Ghanaian government and funded in part by the International Bank for Reconstruction and Development of the World Bank, the United States, and the United Kingdom.
In periods of drought, the water in Lake Volta is rationed and less electricity is generated. During these times, cities in Ghana are subjected to rolling blackouts to lessen their consumption of electricity. Ghana's Volta River Authority has contracts with neighbouring countries for electricity. These contracts are given higher priority than the customers in Ghana's own cities. Though Kaiser Aluminum is a major user, and the dam was constructed in part for the smelting of local bauxite, the economics have turned out such that raw materials have to be imported to keep the industry running. The Volta Aluminum Company(VALCO) is another major user. Valco had said previously that they would use the local bauxite. When the dam was built, they instead imported the necessary material (alumina, what bauxite is made into) from Jamaica.
It is interesting to note though that, the Akosombo Dam directly provides Ghana with only 20% of its energy capacity, with the rest of the 80% being generated for the benefit of the American-owned Volta Aluminium Company. Furthermore, the Ghana Government was compelled, by contract, to pay for over 50% of the cost of Akosombo’s construction. However, the country was allowed to benefit from just 20% of the power generated. Some commentators are concerned that this is an example of neo-colonialism.
Background
The development of the Volta River Basin was initially proposed in 1949,but because they didnt have the sufcient money, the american company Valco lended them enough so that the dam was managed to be built. under the British Colonial Administration . Formerly known as the Gold Coast until 1957, when Ghana became the first sub-Saharan nation to gain its independence from colonial rule . At that time, Ghana’s limited economy was sustained solely by the country’s cocoa production . As a newly independent country, Ghana became motivated to expand the economy by way of industrial development. The elected Prime Minister of independent Ghana, Dr. Kwame Nkrumah, adopted the Volta River hydropower project to grandly represent the beginning of a new and growing economy .
The final proposal outlined the building of an aluminum smelter 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 for aluminum production without foreign importing of the bauxite employed in smelting. Development of the aluminum industry within Ghana was dependent upon the proposed hydropower.
The proposed project’s aluminum smelter was overseen by the American company, Kaiser Aluminum, and is operated by the Volta Aluminum Company (Valco). The smelter received its financial investment from Valco shareholders, with the support of the Export-Import Bank of Washington. 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 dam, on the other hand, received its funding through loans provided by the World Bank, and support from both the U.S. and the U.K. These loans came to a total of about $40 million (48 million cedis), while the government of Ghana supplied the other $69 million (84 million cedis) necessary for constructing the hydropower plant at Akosombo. The estimated total cost of the project, in its entirety, was estimated at $258 million (313.7 million cedis).
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 Dr. 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 lake reservoir behind the dam, the fishing available within the lake, lake transportation and communication, and the welfare of those approximate to the lake.
The construction of the Akosombo dam required the flooding of the Volta River Basin and its upstream fields, resulting in the creation of Lake Volta which covers 3.6% of Ghana’s total land area . Lake Volta was formed between the years of 1962 and 1966, and necessitated the relocation of 80,000 people into 52 resettlement villages two years prior to the lake’s completion; the resettlement program was under the direction of the VRA . The 80,000 people, that represented 1% of the population, made up 700 villages prior to resettlement . Two percent of the resettlement population were riparian fishers and most were subsistence farmers . The Eastern Region of Ghana and the populations incorporated within its districts, was most subject to the project’s effects. At least two districts within the Eastern Region represent indigenous ethnic groups .
Impacts of the Akosombo HEP
- DDGenerally, the Akosombo Hydroelectric Project (HEP) benefited some industrial and economic activities from the addition of lake transportation, increased fishing, new farming activities along the shoreline, and tourism . The power generated has provided for primary interests within Ghana, while also supplying power to the neighboring countries of Togo and Benin . However, Ghana’s industrial and economic expansion triggered an even higher demand for power, beyond what could be provided by the Akosombo HEP. By 1981, a smaller dam was built at the town of Kpong, downstream from Akosombo and further upgrades to Akosombo have become necessary for maintaining hydropower output . 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 . Increasing demands for power are beyond what can be provided by current electricity allocation and generation. Power demands, in correlation with unforeseen environmental trends, have resulted in the experience of rolling blackouts and major power outages . A trend of decreasing lake levels has been observed, which sometimes results in level below what’s required for the minimum operation of the Akosombo dam . In response, speculation upon further sites for dam construction and installment, such as the proposed Bui Dam, still continues along Volta tributaries .
Biological Habitat
In the time following the construction of the dam at Akosombo, there has been a steady decline in agricultural productivity along the lake and the associated tributaries . 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. Upstream agricultural systems are losing soil fertility without the periodic floodings that brought nutrients to the soil before the natural river flow was halted by the dam . 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 . The nutrient enrichment, in combination with the low water movement, has allowed for the invasion of aquatic weeds (Cerratophyllum). These weeds have become a formidable challenge to water navigation and transportation .
Human welfare
The presence of aquatic weeds along the lake and within the tributaries has resulted in even greater devastation 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 and malaria . Since the installment of the dam, these diseases have increased remarkably. In particular, resettlement villages have showed 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 . Children and fishermen have been especially hard hit by this rise of disease prevalence . Additionally, the degradation of aquatic habitat has resulted in the decline of shrimp and clam populations . 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 .
Socioeconomics
The loss of land experienced by the 80,000 people forcibly relocated meant the loss of their primary economic activities from fishing and agriculture, loss of their homes, loss of their loved ones’ grave sites, loss of community stability, and the eventual loss of important social values . The resettlement program demonstrated the social complexities involved in establishing “socially cohesive and integrated” communities . The high death rate among the elderly community members following their resettlement is representative of the psychological and social burdens accompanying a resettlement program . Insufficient planning resulted in the relocation of communities into to areas that were not capable of providing for their former livelihoods and traditions . The loss of the naturally fertile soils beneath Lake Volta essentially led to the loss of traditional farming practices . 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 . Increased economic risks and experiences of poverty are associated with those communities most impacted by the Volta River’s development . The extensive human migration and degradation of natural resources within the Volta-basin area, are the products of poverty in conjunction with population pressure .
Disease
Increased human migration within the area has been driven by poverty and unfavorable resettlement conditions . This migration enabled the contraction of HIV and has since led to its heightened prevalence within Volta Basin communities . The districts of Manya Krobo and Yilo Krobo, which lie within the southwest portion of the Volta Basin, are predominately indigenous communities that have attained a disproportionate prevalence of HIV . 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 . Ten percent of the child-bearing females from these two districts migrated out of their districts during this time . In 1986, “ninety percent of AIDS victims in Ghana were women, and ninety-six percent of them had recently lived outside the country” .
Physical Environment
Future conditions are likely to worsen. Earthquakes have already become more common due to the crustal re-adjustments from the added weight of the water within Lake Volta . There is an eastward shift of the river’s mouth from the changes to the river’s delta zone 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.
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