What I'm interested in the second picture is the separate rectangle within the larger show room building. I'm guessing that's where the load/unload will take place.
Although I'm fairly certain the pour to the north of the rides is for the waterfall as others have stated, if there will be an outside portion of the boat ride, now is when we should start to see those portions cast in place as well.
With such a large space between the floating mountain facade and the banshee ride, I wonder if the banshee show building exterior will be themed to the 'Tree of Souls' for the boat ride? The building seems to be gaining some additional features that I couldn't discern in the leaked plans.