Case Study Of The Akosombo Hydroelectric Dam Environmental Sciences Essay

The construction of Akosombo dam on the Volta river basin in Ghana created Volta Lake the largest man-made lake by surface area in the World. The purpose of this study was to examine the benefit and consequences of the dam on social, environmental and health issues. Critical analyses of primary literature over five decades were reviewed and some management solutions were outlined. The Akosombo hydroelectric project (HEP) contributed to accelerating of Ghana’s economic development through industrial and mining sectors as well as for providing cheap electricity for domestic and commercial consumer. Fishing, transportation and tourism were positive benefit from the dam. However, negative impacts like the resettlement of 80 000 people, increase in health problem like the high rate of HIV, socio economic deprivation and injustice and destruction of the ecosystem. The greatest challenge facing Akosombo is management and lack of research on the aquatic systems at the basin. Key recommendation includes environmental compensatory approach and research into environmental flows of the Volta River. Ultimately, it is important for future HEP in Ghana be precede and adheres to EIA reports and involves stakeholders from planning to post construction stage to maximize overall development benefits, encompassing economic, social, and environmental impacts

INTRODUCTION

Hydro-electric power is an important source of energy for many countries especially in the tropical countries without advance technological development. In 2007, 3.2 % of global energy consumption and 20% of electricity generated came from hydropower (IEA, 2010). In many countries especially in Central America and Sub-Sahara Africa over half of all electricity generated comes from HEP (Anderson et al. 2006a and Gyau-Boakye 2001). The major advantages of HEP which makes it a preferred renewable energy sources are cost, zero air pollution, longer life span of plant, the low level of expertise for running and maintenance of HEP and lack of post production storage problems. Perhaps the biggest advantage hydropower enjoys over other sources is the fact that the cost per unit of electricity generated from hydro is cheaper than any other source.

Globally, the trend of newly constructed hydropower has shifted from the temperate region to the tropical regions in the last two decades (Pringle et al., 2000). Dams construction is expected to double in developing countries due to expanding human populations, increasing rural electrification, and growing demands for electricity in the developing countries (Anderson et al. 2006a). Although the bulk of hydrodams constructed recently have been in the developing countries with China leading the number of newly constructed dams, the recent announcement of a major dam to be constructed in Alaska indicate the pull of hydro even as undaming of major rivers is taking place. It is projected that hydropower production would grow by nearly 60% in 2050 if the current rate of construction is maintained.(dams.org, 2010)

Despite the numerous advantages, hydro-electric power (HEP) causes more ecological damage than all the rest of the renewable energy put together. The damage done to the natural flow system of rivers and associated impact on the ecosystem are documented in many studies (Anderson et al., 2006b; Pingle et al., 2000; Craig, 2000). They include natural flow alteration of a river, destruction of hydrologic connectivity, impeding the migration of fish and other aquatic biota effects. Asides the ecological impact, there is also the issue of social impact on the communities which includes changes in the landscape leading to flooding, displacement of local residents, increase in health risk factors as a result of the dam and reported deaths from dam failures.

The Volta River Basin is located in West Africa and covers an estimated area of 400,000 km2 and is spread over six West African riparian countries (Burkina Faso, Ghana, Togo, Benin, Cote d’Ivoire and Mali). There are a number of dams located within the Basin of which three large ones, Akosombo, Bagre and Kompienga, are solely for hydropower purposes. The Akosombo dam, which was constructed from 1962 to 1966 in Ghana, is by far the most significant structure built in the basin since the resulting lake is the one of the largest man-made lake in the world (Barry et al., 2005) and covers 4% of the surface area in Ghana however, the actual reservoir only has a surface area of about 8500 km2, an average depth of about 18.8m and a shoreline of about 5,500 km (Barry et al., 2005).

The formation of the lake led to the generation of economic activities like transportation, fishing and tourism along the lake (Kumi, 1973). Although the primary purpose of the Akosombo hydrodam was to supply electricity for Volta Aluminum Smelting Company (VALCO) located 80km from the dam at Tema, Ghana, it contributed to accelerating of Ghana’s economic development through industrial and mining sectors after its construction as well as for domestic and commercial consumers. Currently the dam supplies around 85% of Ghana’s electricity need providing an average annual output of 6100 GWh. Despite the benefit of the dam to the country the long term environmental and social cost has been staggering.

This paper seeks to review the impact of hydrodams in the Volta Basin with primary focus on the Akosombo dam. The aim of this study explores the biodiversity challenges facing the basin as a result of the HEP construction and review the impact on the social and the ecological aspects of the basin. Primary literature would be used to assess how the dam has positively or negatively affected the socio-environment aspects [the ecosystem (physical components, the biological community and water quality), social, health and economic impacts] of the basin. The study would focus specifically on the Akosombo but inference would be drawn from other dams across the basin in the analysis. Based on the study, outlined recommendations and solutions would be made for existing and future dams that might be constructed on the Volta River

THE AKOSOMBO HYDROELECTRIC PROJECT

The Volta Basin lies within latitudes 5°.30 N and 14°.30 N and longitudes 2°.00 E and 5°.30W. It is located in West Africa with six riparian countries (Ghana (42%) and Burkina Faso (43%) and the remaining 15% in Mali, Côte d’Ivoire, Togo, and Benin) with Ghana occupying the downstream of the basin (figure 1). The building of the Akosombo dam follows almost a period of two decades of planning which began in 1947 when the first feasibility studies were conducted on the potential for volta river as a hydropower source. The bulk of the funding for the project estimated $ 260 million. was secured by Kaiser Aluminum from a US bank under persuasion from President Eisenhower in face saving from public relation disaster (GW 2010) The HEP was directly linked to efforts made to develop the huge Ghana’s integrated bauxite to aluminium industry. The actual construction of the dam took place within1962-1972 under the management of the Volta River Authority (VRA) who were legally mandated by the Act 46 to be caretakers of all Volta River related activities in Ghana. The Volta River Authority (VRA), a government owned utility, is largely responsible for electricity generation and transmission in Ghana. There were three phases of the project, phase one was the installation of 588MW unit of electricity which was completed in 1966m. The second phase involved an addition of 304MW electricity which resulted in total of 912 MW at the Akosombo dam. The last phase of the project was the setting up of a smaller HEP dam, 21km downstream, at Kpong. In terms of dam classification, the Akosombo dam is often classified as large dam whiles that of Kpong is classified as small hydro dam. Today a total of 1072MW of electricity is generated by the Akosombo HEP (VRA, 2010).

The first phase of the projected resulted in the creation of Lake Volta (man-made lake) which is the most significant water body in the Volta basin. The lake covers an estimated area of 8500 km2, a length of 400 km and a shoreline of 5500km (Gyau-Boakye 2001) but rather shallow with a maximum depth of 113m. It receives flows from three rivers – Oti, Black Volta and White Volta and discharges into the lower Volta river and then the Atlantic Ocean. The maximum capacity is around 150,000 million m3 of water at its peak of 278 feet. (VRA 2010)

The main objective of HEP production is to make VALCO energy sufficient so that its activity which is mainly aluminum smelting would be proceed without interruption. The other objectives were to supply electricity for both domestic and industrial use and also export to the basin sharing countries (Benin and Togo). The Volta River Authority (VRA) a government owned entity was established in 1961 under the Volta River Development Act 46 and tasked with the management, maintenance and sustainability of the Volta River and HEP production. The act also gave the VRA the responsibility to generate and transmit electricity as well as safe-guarding the health and socio-economic well being of the inhabitants of the communities alongside the lake. Prior to the flooding stage of the dam, the VRA had to relocate people inhabiting traditional, administrative and all other lands that were to be inundated.

BENEFITS OF HYDROPOWER FOR GHANA

The construction of the Akosombo HEP and the creation of the Volta Lake have provided several positive benefits. The Akosombo HEP provides over 85% of all electricity generated in Ghana (Winston et al., 2006). The electricity generated has encouraged economic and industrial development in Ghana. Prior to the construction of the Akosombo HEP, Ghana’s total power usage was around 70MW and this was isolated with individual standalone power supply system which was owned by industrial establishment such as the mines, factories and other major institutions (Aryeetey, 2005).and assess to electricity was restricted to less than 3% of the population. Today an estimated 60% of the population has access to electricity including 20% of the rural communities (ECG, 2008). Over two-thirds of all the electricity generated goes to industries and commercial entities; this led to rapid expansion and immigration of industries into Ghana from other West African countries to take advantage of the cheap electricity available from the HEP. As a result Ghana’s economy is twice the average of the West African sub region (IMF, 2010). In years of drought where HEP energy generation has been poor, unemployment rate rises exponential attesting to a positive externality of the Akosombo dam.

The creation of the Volta Lake led to increase in fishing stock thereby making fishing a lucrative business to the inhabitants along the lake. Similarly, farming activities also intensified along the 5500 km shoreline especially locations downstream of the lake as a result of water availability for the purposes of irrigation and more importantly alluvium sediment deposition which is very fertile and has high content of organic matter. Also the navigation on the Volta river has changed significantly serving as a mean for transportation for goods and people across the lake where road are poor or unavailable. To the inhabitants creation of the transportation route on the lake which stretches from south to north has been one of the important benefits to the communities. The direct tourism impact resulting from the lake includes opening up part of hitherto inaccessible attractions (because of the location of the dam, the sight of the lake the environment, etc.) to both local and international travelers. The lake and its designated national park Digya located at the west shore of Lake Volta and the resort island have provided a popular holiday destination.

CONSEQUENCES OF AKOSOMBO HYDROPOWER

Like all hydropower dams constructed the Akosombo HEP have had a social, environmental and physical impact on the communities upstream, downstream, the project site and even beyond the extent of the dam.

On the social front the most prominent problem that is directly linked to the HEP is the displacement of 80,000 people across 700 villages in low lying areas and resettle them into 52 new villages (Kalitsi,2000). The lost of the original communities resulted in many socio-physiological problems in the communities including high death rate among the aged, breakdown of cultural practices and breakdown of traditional law and order (Gyau-Boakye, 2001). The higher death rate is attributed to the “grieving for the lost land syndrome” (Okoh, 1986). The Volta lake creation leads to a loss of 3.6% of the total land surface of Ghana including forest land to the reservoir.(Fobil et al. 2001) The lost land lead to decline in the primary economic activities of crop and livestock farming for most of the communities both downstream and upstream of the dam. As a result of less arable land to farm the men switch to fishing while most of the women (a taboo for women to fish in Ghana) were involved in prostitution as a profession to satisfy the male workers whom were building the dam. (Suave et al. 2002) In terms of the standards of living the inhabitant of the project site Akosombo enjoy the best living condition not only in the entire Volta basin but better than the major urban centers in Ghana. Surprisingly, the upstream communities and downstream communities are among the poorest in the country lacking access to basic necessities like hospital, roads, proper sanitation and water facilities. Perhaps the most ironic social injustice to the communities upstream and downstream is that it took three decades to be connected to the national electricity grids.

The HEP have increased the health related issues among the communities living around lake except in the town of Akosombo (Zakhary, 1997). Sam (1993), in his survey concluded increases in diseases such as schistosomiasis (bilharzia), malaria, onchocerciasis are directly due to Akosombo HEP. This is dues to the presence of aquatic weeds and increase in the population of water-born vectors like mosquitoes, black fly and snails.(Gyau-Boakye, 2001) Specifically, Urinary schistosomiasis (Bilharzia) has seen the increase of the incidence from 2% to 32% at Mepe,( downstream) and 0.5% to 27.4% at Adawso/ Okradjei, (upstream) along the lake (Zakhary,1997). Malaria has increased by an average of 10% both upstream and downstream since the construction of the dam. The fly, Simulium damnosum which cause Onchocerciasis (river blindness) also increased downstream in Kpong between 1970 to 1980 due to the new breading grounds created by the Akosombo dam, however the fly was not found again after completion of the smaller dam in Kpong in 1982 (Gyau-Boakye, 2001). As stated earlier

The period between after the construction of the dam (1970-1980) coincide with the worst economic period in Ghana and the associated political uncertainty forcing the migration of the young women whom were inducted into prostitution during the dam construction to the various neighboring countries. Sauve´ et al 2002 concluded that the high HIV prevalence rate (14.1% compare to 3% for the country) in Manya Krobo and Yilo Krobo districts located west and south of the Akosombo dam to a greater extent, a consequence of construction of the Akosombo dam in the 1960s prompted economically driven migration, specially to Côte d’Ivoire, where many migrants became infected with HIV. This is surprising and rather peculiar to find a prevalence of HIV in semi-urban area that is much higher than those found in the country’s major cities. (Sauve´ et al 2002).

In terms of the physical geomorphology, the dam have created physical environmental problem. The most obvious is the increase in seismic activities around the dam since the construction of the lake. 4 major earthquakes of magnitude 5 or higher have been recorded in the area. Since there is no geological fault zone present in the lake, it is believe the earthquakes are due to the overloading of the geological bedrock underlying the lake with which is triggering the active Akwapim fault (Gyau-Boakye, 2001). Kumi (1973) concluded that the earthquakes might be due to readjustment associated with the lake in-filling. Another physical observation is that, sediments load have decrease by about 60mg/l downstream of the dam as a result of the impoundment (Barry, 2005). The lack of sediment has lead to the erosion of the coastline in the neighboring Togo and Benin at a rate of 10-15m/y (Gyau-Boakye, 2001). Another evidence of change is that the morphology of the delta have shifted 12 km eastward from the original lower Volta entre point to the sea leading to coastal erosion at Ada.(Arp and Baumgaertel, 2005). In accordance with the behavior of tropical dam microclimate the temperature and rainfall in the south eastern part of Ghana is higher than the average in other parts of the basin and this is squarely attributed to the Akosombo HEP (Kumi, 1973, Rosenberg et al., 1990 .Opoku-Ankomah and Amisah 1998).

The Akosombo HEP impact on the ecosystem unlike social and health issues have not been fully investigated and well. Fish and other aquatic biota are very sensitive to the hydropower operation due to the ability of the dam to alter and or blocking the migration resulting in genetic disconnect between species population (Baxter, 1977 and Pringle et al., 2000). The first compressive study sixteen (16) months after the construction of the dam by Petr (1967) showed that relative abundance of fish in the Lake were compared with those obtained from fish landings on the Black Volta and from the Niger river survey (Petr 1967). However the study did indicate an increase in plankton feeders, shell fish, Tilapia and a decrease Mormydiad and Alestes along the north-south axis of the river (Petr 1967). In 2000, about 87,500 metric tons of fish catch were recorded from the lake representing 98 % of the inland fresh water fish in Ghana (Braimah, 2001).Current fish estimated yield are 42-52 kg/ha/year based on catch statistics with Tilapia dominating the catch. However, the current trend of removal of standing timber in the forest which became part of the lake, in conjunction with overfishing, has negatively impacted the fish stocks especially in shell fish. Recent studies involving 165 fish sample covering 9 species in both the Akosombo and Kpong dam with Lake Bosomtwe (a pristine lake in Ghana) for mercury concentration showed levels below World Health Organization limit of 0.5 μg g−1.suggesting no mercury in the HEP lakes mercury (Agorku et.al. 2009). Unlike newer dams constructed with EIA both the Akosombo and the Kpong dams do not have any fish ladders available for fish migration.

In terms of the damage done to the ecosystem are unique and site-specific but generally the impacts invariably affect biota and biodiversity (Anderson 2006a). The Akosombo HEP is ranked in the top ten in terms of both social and environmental damage index (dams.2010). Flooding in the downstream communities is an annual event. The Afraim plain is a low lying rich farm land area suffers annually from the flow of the spillway river. A river flow is highly circumvented leading break in river connectivity. Although not unique to Akosombo, studies have shown that the large-scale impoundment may eliminate unique wildlife habitats and affect populations of endangered species. The Dibgya National Park close to the lake is a wildlife refuge site and it would be interesting to know how the lakes have affected wildlife in the park. Contrary to popular belief that HEP are emission free, scientific fact indicates that large dam projects and their reservoirs produces very significant greenhouse gases (carbon dioxide, methane and nitrous oxide ) from the rotting of organic matter. The advocacy group International Rivers (formerly known as International Rivers Network concluded from their study Figure 2 that tropical dams in some case might be dirtier then fossil fuel in terms of GHG emission (IR, 2008) .Takeuchi (1997) concluded from his global survey of dams that the damage done to the ecosystem and electricity generated from Akosombo is very disproportionate. These impacts include loss of the actual wetlands as they are modified to suit particular irrigation practices and associated losses in biodiversity. (Takeuchi (1997)

CRITICAL ASSESSMENT OF THE AKOSOMBO DAM50 YEARS LATER

The Akosombo dam in 50 year of operation has been the cornerstone of Ghana’s economic and industrial development. Likewise the HEP has cause and continues to remind us daily of the socio-environmental negative impact of living with dam.

The original goal of the project in addition to the generation of electric power for industry urban and rural household was to provide opportunities for large-scale irrigation, modernization of agriculture, promotion of factories and industries, and the establishment of tourist facilities. Fifty (50) years later, it appears that the need at the time for the country to have a cheap source of electricity did have overriding priority over other considerations (Arp and Baumgaertel, 2005). The generation of electricity as stated earlier lead to the positive economic and industrial development along the eastern coast of Ghana. Analysis of the project goal and the implementation of the original blue print indicated that the VRA woefully mismanage the dam’s activities starting from the original resettlement scheme to their inability to meet the electricity need of the country. The resettlement of the communities and the compensation promised to the inhabitants were not fully paid, farming lands were insufficient for the villages while a lot of communities downstream whom were not accounted for were ultimately affected by the dam. According to the available data (ECG 2010) and personal observation the VRA after 50 years of operation have failed to meet its goal of providing electricity to the citizenry especially the social injustice that the majority of the affected people by the project were not connected to the national grid until recently .This undoubtedly showed that the authorities neglected the majority of the people affected by the dam to the benefited of the urban dwellers (Girmay, 2002). To their credit VRA undertook some activities towards the fulfillment of non-generation goals like the creation of the Akosombo Textiles Company, Kpong Farms Limited, the Akosombo Hotel Limited and Volta Lake Transport Company Limited (VLTC) to boast jobs and economic activity within the region. The downside to these projects is that inhabitants did not have the specialized skills and education levels required to take advantage of working in textiles industries or operating advanced machinery in the 1960’s. The VRA irrigation and modernization of agriculture programs collapsed after at the implementation stage. Such program would have been more beneficial to the communities living along the dam since prior to the construction of the dam the majority of the people were into farming.

The Akosombo dam and many others constructed in the developing countries before the 1972 Stockholm Conference on the Human Environment were without any environmental impact assessment (EIA) plan. In 1974, Ghana was the first country in Africa to establish an environmental governing body to deal with all environmental issues under one agency known as Environmental Protection Council (Appiah-Opoku, 2001). Ironically, the Kpong dam whose construction began in 1976 did not have EIA in place. In order to combat some of the negative environmental impacts of the project the VRA introduce numerous cut and fix approaches. These programs include afforestation program along the banks of the lakes, weed controlling measures to control bilharzia., dredging activities at Volta estuary and the creation of Resettlement Trust Fund for remediation some of the socio-economic impact mitigation (Girmay, 2002, Fobil et.al. 2003,). The success of these programs is difficult to measure since most of them were subjective in nature. The VRA did have some environmental management programs and policies but they suffered from implementation and enforcement (Girmay, 2002).

The question often asked in the view of the social and environmental damage done by the HEP is if this cost is justifiable. To address these issue in the context of Akosombo HEP present a dilemma. Ghana until recently discovery of oil along it shore did not have any fossil fuel or expertise in nuclear energy to produce electricity from these sources. Hence, the HEP project was the lifeline in meeting part of its energy demand. As stated earlier studies have shown that the amount of greenhouse gasses produces by hydropower is lower than the corresponding fossil electricity (Anderson 2006a). Although critics point to the fact that Ghana’s overreliance on HEP have hamper the development of alternative renewable energy sources which have affected the country in times of drought. The supply of cheap electricity to neighboring countries like Togo and Benin mitigate their coastline erosion by the project.

Ultimately, the amount of electricity produced from the Akosombo/Kpong HEP and the social and environmental damage to the basin is not acceptable. The major destruction of the ecosystem habitats and the negative health and social impact on the upstream/downstream communities is much bigger than comparable dams elsewhere. For example Japan produces 2300MW of electricity from HEP and the damage is a tenth of what occurs in Akosombo (Takeuchi, 1997). Although the HEP have been helpful to the country economically, with proper management and sustainable planning; the level of success would have been higher and the environmental impact greatly reduced. With benefit of time the original proposal should have been implemented and enforced effectively. This would have reversed the trend today which has led to the communities upstream and downstream been among the poorest in the country.

RECOMMENDATIONS

The positive impacts and the negative effects of the Akosombo have been highlighted in this paper. In view of the negative socio-environmental factors like downstream flooding, resettlement of communities, ecosystem destruction among others it is important strategies are put in place to mitigates these effects and protects the ecosystem from current and future HEP.

One way of mitigating the environmental and social cost is through environmental compensatory project approach or ‘offsets’. For example, the recent plan of the Brazilian government to build a third world largest dam requires the company who wins for the bid to pay an excess of $800 million to offset environmental damage and relocation. Also in India there is a legal requirement that forests flooded by reservoirs must be replanted elsewhere. Introducing such concepts in the planning stages of the dam would really help ensure that significant and unavoidable adverse environmental impacts are counterbalanced by a positive environmental gain, with an inspirational goal of achieving a ‘net environmental benefit’. This approach must be fused with properly developed policies for resettlement and compensation prior to the construction of dam so that all stakeholders know the detail and what to expect or contribute toward the compensated package in cash and in kind. The resettlement costs must cover all inundated properties as well as emotional and psychological cost which is often ignored. The package aside covering individual cost could also be extended to cover basic facilities and infrastructure development such as roads, health centers, schools, potable water, etc.

On the other hand environmental damage could always be factored into the price of electricity through ecological tax in order to reflect the true cost of power. This tax revenue could go into a standing trust fund which would be essential to sustain the programs needed to ensure the effective mitigation and compensation of environmental effects of the hydro development. To protect the integrity of the lake, measures should be taken to check deforestation by protecting the original forests. Additional compensatory measures may include either trust fund established through grants from developers (for example Harvey Basin Restoration Trust, Australia) or trust funds that manage parts of the revenue stream and for environmental purposes. This latter model was proposed for the planned Nam Theun II dam in Laos, with the intention of creating and managing a National Park in the catchment. The plan has the potential to benefit both forest ecosystems and the lifespan of the dam through reduced sedimentation. This approach could certainly benefit Ghana’s fight against deforestation.

In the planning stages of a dam construction, is very important project teams realize the need to maintain adequate water flows and other habitat conditions to sustain river health and associated ecosystem services in river reaches located downstream of dams. When ecosystem services valued by local communities are fully considered and integrated along with all other management objectives, the prospects for optimizing both dam- and ecosystem-related objectives would be greatly enhanced. Project teams can help avoid the loss of ecosystem services by considering environmental flow needs at the very earliest stages of hydropower dam as part of the EIA development. The specification and provision of environmental flows is key to sustainable hydropower development and water management (Scudder, 2005). When environmental flow needs are assessed scientifically, water managers and hydropower dam planners and operators will understand the extent to which historical water flow patterns can be altered by hydropower operations without compromising a river’s health and associated social benefits. Active and early engagement of relevant water managers and dam planners, scientists, and other stakeholders in the planning process will help build a strong and influential constituency and foster a coordinated and consistent vision for the protection and management of a river. (Pingle et al., 2000; Craig, 2000, Anderson et al., 2006a, b Raschid-Sally et.al 2008) With proper input from stakeholders and attention to the needs and values of diverse interests, a tradeoff analysis can be undertaken to explore the optimal balancing of interests (Raschid-Sally et.al 2008)

One current approach the VRA and other operator of dams on the Volta basin is the management of flood to limit its impact. New Dams and even old ones must can be designed or altered for multiple purposes such as flood control and HEP generation. By storing some portion of floodwaters on the floodplain instead of a reservoir, the total volume of necessary flood storage space in the reservoir can be reduced. By protecting or reactivating downstream floodplain areas or allowing agricultural areas to be flooded occasionally, the flood storage requirement in the upstream reservoir can often be reduced substantially. The excess water can be reallocated for hydropower use, water supply, or improved environmental flows downstream of the dam. Reflooding of natural floodplains can bring substantial ecological benefits, such as providing additional spawning and feeding opportunities for fish and enabling the floodwaters to fertilize and moisten floodplain areas used for agriculture or grazing.( Craig, 2000) Likewise , the coordinated operations of cascades of dams: on the Volta river can maximize power generation at upstream dams to enable lower dams to serve more of a re-regulating function, thereby minimizing flow alterations in the downstream river. Currently this approach is been developed by the transboundary water management Volta Basin Authority (VBA) and it is hope the implementation of such approach would be beneficial to the basin communities. The VBA IWMR policies would be the key to protecting the ecosystem in the basin.

In terms of operational mode management The VRA can increase its generation of electricity from its Thermal plant in Aboase to ease the pressure on operating HEP at maximum capacity. For example base and peak load have daily and seasonal operation influence the release of water downstream, if alternative power sources are used, limits can be placed on the range within which flow is released from a dam on hourly or daily basis. A minimum flow release requirement can be established to prevent the hydropower dam from shutting off all downstream flow when electricity is not being generated. A maximum release during normal operations can also be set so that high flow releases during peak power production does not damage ecosystems or communities downstream

Another suggesting is passing sediment around or through a dam can also help alleviate dam-related impacts in the downstream river ecosystem In addition to providing dead storage to accommodate sediment deposition in a reservoir; newer dam constructed in future must include features to move sediment around or through the reservoir. Sediment bypass structures are designed to route sediment inflows into a bypass outlet (a channel upstream of or in a reservoir that bypasses the dam and rejoins the river below the dam) and subsequently discharge sediment and water below the dam, thereby keeping sediment from flowing into hydropower turbines.(Anderson 2006b) Sediment flushing involves opening sediment sluice gates or other low-level outlets (usually located near the bottom of a dam) and lowering reservoir levels to cause water in the reservoir to begin to flow through the reservoir and outlets. fish passage structures: used to enable fish and other mobile aquatic organisms to move upstream and downstream of a dam. It is important each species have a specific designed requirement since there is difference in how they move. Aquatic wildlife may migrate along riverbanks, requiring passages on each side of a barrier (Anderson 2006b)

CONCLUSION

There is no doubt that Akosombo HEP has contributed significantly to the economic growth of Ghana but also continues to remind us of the extent of damage caused socially and environmentally. Socially, HEP resulted in the displacement of people, lost of homes and properties, lost of original communities, increased rate of migration and high death rates as a result of “grieving for the lost syndrome” and HIV-AIDS. Another social impact can be linked to the increased rate incidence of diseases such as schistosomiasis (bilharzia), malaria and onchocerciasis associated with the existence of the dam as these diseases has no or insignificant records prior to the construction of the dam. On the whole, the resettled communities especially those upstream and downstream portions of the dam are among the poorest communities in Ghana since they lack access basic amenities facilities like roads hospital, roads, proper sanitation and potable water. Today annual flooding of communities downstream the dam, example Afram Plains, have led to migration to the upstream catchment areas. In terms of the environment, the physical geomorphology was altered hence creating physical environmental problems like erosion (even affected neighboring countries like Togo and Benin), earthquakes (results of increased seismic activities in the area), alteration in the natural flow and flood cycle and alteration of the microclimate in the basin. Another major effect was the impact on the biota within the environment, especially fish, as a result of dam blockage upstream and downstream which lead to genetic disconnection between species.

Analysis of the project’s goals has shown VRA mismanaged the dam and have failed the with regards to almost all the objectives like electricity generation, resettlement and compensation as well as improving the life of communities in the vicinity of the dam. This study has shown that for 50 years of operation, VRA has failed to meet its goal of providing electricity to citizens especially people who were affected by the project. VRA promised the affected communities of creating jobs, accelerating economic activity, improving irrigation and modernizing agriculture in the region which they failed to do. Privatizing and liberalizing the energy generation market would attract investor and encourage competition in the energy sector in Ghana. Although Ghana was the first country in West Africa to establish an environmental body There is very little research down to ascertain the impact of the dam on the ecosystem locally a situation that requires immediate reversal.

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INFORMAL REFERENCE

The World Commission on Dams www.dams.org

Volta River Development Act, 1961

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Volta River Authority http://www.vra.com/

International Monetary Fund http://www.imf.org/external/

Figures

Figure 1.