Project co-owner EPM reiterated "its willingness to collaborate with everything that is pertinent" to the investigation by the attorney general's office.
The A-1 and A-2 tenders are scheduled to take place in December.
According to weather institute Ideam, there is a 70% probability that El Niño will affect Colombia with light or moderate intensity between the fourth quarter this year and early 2019.
Meanwhile, Lima's "first" electric bus hits the streets.
The plant would treat 70Mt of accumulated waste to generate power for the city's metro system.
The planned power plants total 1,500MW.
Protests over blackouts are reportedly increasing.