La Confluencia Hydroelectric Plant

The La Confluencia Hydroelectric Plant began its commercial operation on May 1, 2011. La Confluencia captures the waters of the Tinguiririca, Portillo, and Azufre rivers, as well as four other smaller streams: Estero la Gloria, El Ciruelo, Los Humos, and Riquelme. Its main intakes are Portillo and Tinguiririca.

This plant has two main branches: the Tinguiririca branch and the Portillo branch. The first consists of a reservoir with a capacity of 1.2 million m3, which receives the flow from the Tinguiririca, La Gloria, and El Ciruelo intakes, and has a 12 km-long intake tunnel. The second branch operates with a 9.2 km tunnel and carries the water collected at the Portillo intake and the contributions from the Azufre, Los Humos, and Riquelme intakes. Both tunnels converge at different levels in a vertical shaft that receives the flow and directs it to the pressure tunnel and collector, which carries the water to the powerhouse. Finally, the water is returned to the Tinguiririca River bed or can enter the tunnel of the La Higuera plant, allowing both plants to operate in cascade. The La Confluencia plant has an installed capacity of 155 MW. The generated energy is transported through an 18 km-long transmission line that extends from the La Confluencia substation to the Puente Negro substation, located in the Chimbarongo commune – owned by Celeo Redes – from where it is injected into the National Electric Coordinator (CEN).

Generation GWh/year

MW Installed Capacity

Contractor Constructor Hochtief-Tecsa SA (Chilean-German)