Акосомбо бөгеті және Вольта көлі: құрылысы, әсері мен мәні

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. 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 , 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. The primary purpose of the Akosombo Dam was to provide electricity for the aluminium industry. The Akosombo Dam was called "the largest single investment in the economic development plans of Ghana." The dam's original electrical output was , which was upgraded to in a retrofit project that was completed in 2006. The flooding that created the Lake Volta reservoir displaced many people and had a significant impact on the local environment, 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.

The dam was conceived in 1915 by geologist Albert Kitson, but no plans were drawn until the 1940s. 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. The dam is long and high, comprising a high rock fill embankment dam. It has a base width of and a structural volume of The reservoir created by the dam, Lake Volta, has a capacity of and a surface area of The lake is long. Maximum lake level is and minimum is On the east side of the dam are two adjacent spillways that can discharge about of water. Each spillway contains six wide and tall steel floodgates. The dam's power plant contains six Francis turbines. Each turbine is supplied with water via a long and diameter penstock with a maximum of of hydraulic head afforded. 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. 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. People of 700 villages were relocated into 52 resettlement villages two years prior to the dam's completion; the resettlement program was under the direction of the VRA. Two percent of the resettlement population were riparian fishers, and most were subsistence farmers.

The dam provides electricity to Ghana and its neighboring West African countries, including Togo and Benin. 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. 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. During the latter half of 2007, much of this concern was abated when heavy rain fell in the catchment area of Volta River. 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 , and for several weeks, water was spilled from the lake, causing some flooding downstream.

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. 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.

Until 2023, the last time Akosombo dam community experienced flooding as a result of controlled spillage of the dam was in 2010. 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. The losses include farmlands, houses and properties which were destroyed by the floods. "My entire farm is under the water and so is my house. I was only able to take my clothes. It took me about 14 years to build this house there is nowhere to go, there is no other land to build on," according to one victim.