A consortium on Monday began the work of diverting the flow of Colombia's Cauca River, part of the preliminary stage of construction of the Ituango hydroelectric dam, which will be the largest in the Andean nation and the second biggest in Latin America.

"After months of effort, we've arrived at this unique moment, and with the utmost respect for this great river, the time has come to begin this story and not turn back," the manager of the $5.5 billion project, Brazilian engineer Reinaldo Lino, said.

The CCC Ituango consortium is made up of Brazilian construction company Camargo Correa and Colombia's Conconcreto and Coninsa Ramon H.

The Cauca River begins in Colombia's southwest and runs 1,350 kilometers (840 miles) north before flowing into the Magdalena, the country's longest river.

Its course will be temporarily diverted between the northwestern towns of Ituango and Briceño, Antioquia province, via two concrete tunnels measuring 14 meters (45 feet) wide by 14 meters tall.

The tunnels will carry the river's waters a distance of just over 1 kilometer (0.6 kilometers) through the mountains before returning them to their natural course, engineer Julio Zuluaga of the EPM utility, which is managing the project, said.

A 30-meter-high containing wall still must be built to divert the water and create a dry area to construct the dam, which will take four years to build.

"Today, we're making a commitment to the country to finish the project on time, in December 2018," EPM CEO Juan Esteban Calle said in a press conference.

The goal is to have the dam's eight turbines operating by that date.

The hydro plant will have an installed capacity of 2.4 GW and produce 13,900 gigawatt-hours of electricity per year, sufficient to meet 17 percent of the nation's electricity needs at "more competitive rates," Calle said. EFE