Haven’t seen the episode about the Gate House? Check it out first, it’s where the water from the forebays shown in this episode ends up.
The walkway crossing the Ontario Power Generating Station forebays sits where the Screen House one stood. That structure was used to halt floating debris and ice from entering the three conduits that sit below the Gate House. When hydroelectric generation was running at full capacity, water would flow through the forebays at a rate of 340 cubic meters per second.
The rock excavated the riverside to create the inner and outer forebays has become part of a different Niagara legacy. The 115,000 cubic meters of material was used to build out the nearby (and still very popular) Dufferin Islands recreational area, increasing the size of some of the existing islands and creating several entirely new ones.
The current Screen House walkway is, like so many spots featured on Check In Niagara, part of the Greater Niagara Circle Route.