The consortium will also build two parallel tunnels, both 1km in length and 14m in diameter to divert water from the Cauca river.
It will also build a powerhouse access tunnel which will be 1km long, with a 140m-long gallery.
The hydroelectric power station will be one of the largest in the country on completion, scheduled in 2013, the company said.
Ferrovial Agroman is the construction subsidiary of Ferrovial.
