The 37MW hydropower facility is located on the Song Giang river, southwest of Khanh Hoa province, and the tunnel excavated by Cavico is 3,018ft long and 8ft wide.
Upon completion, the power plant is expected to generate 141 million kWh of electricity annually.
The plant, which has a total estimated investment value of approximately $50m, will be connected to the national grid to help ease the electricity supply shortage in the country.
Cavico secured a contract to excavate a 2.8-mile long headrace tunnel, two sub-tunnels, and a 138ft-high surge shaft in January 2009.
