Associated Press cited Cambodia Prime Minister Hun Sen as saying that the Chinese-built project is expected to help supply electricity for underserved villages and factories.
Sen said: "The dam will provide great benefits to both households and business establishments."
Located on the Stung Russei Chrum River in western part of Koh Kong province, the Russei Chrum Krom project consists of 206MW upper hydropower station and the 132MW lower station and generates output of 1.199 billion kWh (average) annually.
The upper dam, which was put into operation in 2013, is a concrete-face rockfill dam with the maximum height of about 124m, while the lower dam is a roller-compacted concrete gravity dam with the maximum height of 58.5m.
The project has been constructed with an investment of approximately $500m by China Huadian, under a 35-year build-operate-transfer (BOT) agreement with the Cambodian government.
Power generated from the hydro project will be sold to state-owned Electricity of Cambodia at a rate of 7.35 cents/kWh.
Sen was quoted by Xinhua as saying: "The government will earn tax revenue of 12.5 million U.S. dollars a year from the project."
