You seemed to be asserting that without a major user near the dam, they would need to build more transmission lines or otherwise waste the generating capacity a

You seemed to be asserting that without a major user near the dam, they would need to build more transmission lines or otherwise waste the generating capacity available. This seemed unlikely to me, as transmission grids are built with significant redundancy, especially for the high-voltage networks. For example, the transmission capacity for the 8 500kV circuits from Bruce Nuclear (ignoring 3 230kV circuits) is 1.5 times the generating capacity. I wasn't sure about this particular station, but with a bit of digging, it seems like the Massena-Adirondack lines alone (there are several others) can carry 900MW, which is more than the capacity of the power station. So no additional lines should be needed.