Soru

Read the passage below and answer the question that follows:

The Kainji Dam, constructed between 1964 and 1968 across the River Niger in Kwara State, Nigeria, was designed to generate hydroelectric power, control downstream flooding, and enhance navigation. Spanning a total length of 10 kilometers, including its saddle dams, the reservoir formed by the dam created Kainji Lake, which covers an area of roughly 1,300 square kilometers. To facilitate upstream and downstream water transport, a dual-lock system was integrated into the dam structure, allowing cargo barges to bypass the rapids. Although initially commissioned with four generating turbines producing a combined capacity of 320 megawatts, space was reserved within the powerhouse for eventual expansion up to twelve turbines.

Which specific feature was integrated into the Kainji Dam structure to enable cargo barges to bypass the rapids?