Mahama explained that the government of Brazil provided $250 million for the project while Ghana government provided $50 million.
He has described as false allegations that his administration diverted funds intended for the Pwalugu dam.
Addressing delegates of the National Democratic Congress (NDC) in the Bolga Central constituency as part of his 3-day tour, he said funds secured by his government were rather intended for the Juale dam on the Oti River between the Ghana-Togo border and financed by Brazil and the Ghana government at a cost of $300 million.
The Pwalugu dam is part of an effort, which began in 1992, to build 3,000 MW capacity.
He said "So, for only 50-60 megawatts power, the over $400 million was not looking very feasible and it was agreed with the Brazilians that the money should be applied to a different project but should be in the area where the dam was going to be located so that it will benefit the people.
"Then somebody goes and says they have diverted the Pwalugu money'; that is not true because Pwalugu did not reach the stage where the fund had been signed onto."