The wet season from June through August should allow the state-owned Ethiopian Electric Power Office, or EEPO, to begin producing 187 megawatts of electricity from one of the 10 turbines installed at Africa’s tallest dam, he said by phone on Tuesday from Addis Ababa, the capital. The dam is 243 meters (797 feet) high.

“Gibe III will start power generation after the rainy season,” Alemayehu said. “It will be this year.”

The 1,870-megawatt capacity Gibe III is the latest of four large-scale Ethiopian dams built by the government since 2004 to supply nascent manufacturing industries and produce surplus electricity to sell to neighboring countries. Ethiopia is seeking to capitalize on its hydropower-generating capacity of 45,000 megawatts, which the World Bank ranks as Africa’s second-largest after the Democratic Republic of Congo.

EEPO plans to bring a turbine online every month after the plant starts generation, though that will depend on the amount of rainfall in the Gibe-Omo river basin, Alemayehu said.

“If there is sufficient water in the reservoir it will be possible to generate the maximum,” he said. “If there’s no water, you will limit the number of turbines.”

Regulated Flow

The dam will store 11.8 billion cubic meters (3.1 trillion gallons) of water that can be released downstream for power generation or other purposes, according to the project’s website. The Three Gorges Dam in China, the world’s largest hydropower dam, holds 39.3 billion cubic meters.

Ethiopian officials say that in addition to power generation, Gibe III will regulate water flows to end annual flooding in the southwestern South Omo region and provide a year-round supply for downstream irrigation projects.

The flow into Lake Turkana, which is mostly in neighboring Kenya, will be reduced by about two-thirds for an estimated three years while the reservoir is being filled, International Rivers, a Berkeley-based non-profit organization that campaigns against large dams, said last month.

The group also says that the approximately 28 percent of the river’s annual flow drawn off for 150,000 hectares (370,658 acres) of Ethiopian state-owned sugar plantations in the South Omo region will exacerbate shortages at Lake Turkana and threaten the livelihood of as many as 300,000 people.

Conflict Risk

The rapid construction of plantations and the arrival of “hundreds of thousands” of migrant laborers “may significantly increase the risk of conflict” in ethnically diverse South Omo, the Development Assistance Group of donors to Ethiopia, said this month.

Gibe III’s electro-mechanical works were built by China’s Chengdu-based Dongfang Electric Corp. using a $470 million loan from the government’s Industrial and Commercial Bank of China. An electricity-transmission line from Ethiopia to Kenya may be finished in 2018, Alemayehu said. The entire project cost 1.47 billion euros ($1.6 billion), according to the Gibe III website.