On June 7, 2010 Ontario Power Generation announced that construction of the Lower Mattagami project will begin (PDF - OPG press release). To accommodate the upgrade to the Lower Mattagami hydroelectric generating stations, Hydro One will upgrade the existing 230kV transmission line by adding a second 230kV circuit and modifying some of the existing transmission towers in order to incorporate the additional generation. Construction of the line is scheduled to begin in 2011.