The climate changes experts predict a drying of 20 to 30% of the water available in the Great Lakes area in the next century, a forecast already in progress. Environment Canada predicts a 24% flow decreasing. The second part of the book present the "Northern Water" project aiming t doverse an important flow of water from the James Bay to the St.Lawrence basin and protecting both regions from the future cliamtic effects and adding an very important production of energy.