The company expects to invest some US$3.05bn on the dam alone, Herrera said during EPM's first quarter results conference. The utility previously estimated project costs at US$2.8bn.
The eight-turbine dam will be built on the Cauca river and be the country's largest hydroelectric plant. EPM is developing the project as part of a JV with the Antioquia department government.
An SPV named EPM Ituango was created in March to manage development of the project, which is expected to begin operations in 2018.
Earlier this week, EPM announced the approval of US$391mn in financing for the subsidiary.
Herrera added that EPM plans to invest US$2.2bn in energy and water projects through end-2012.