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 8,502 square kilometres, 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, and 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 is also significant for providing the majority of both Togo and Benin's electricity, although the construction of the Adjarala Dam hopes to reduce these countries' reliance on imported electricity. The dam's original electrical output was 912 megawatts, which was upgraded to 1,020 megawatts in a retrofit project that was completed in 2006.