Seems ever-so-slightly concerning that the mechanisms for preventing the bridge from overflowing are based solely on dams and pumps working. I.e., as opposed to building the bridge to float as necessary. Seems like that would be more versatile and lower-maintenance. *shrug* Then again: 1) it's the Dutch, and 2) it's only a man-made moat/lake, so what's the worst that could happen?
Another, more relevant rabbit hole I'm skirting at the moment is reading about how Holland deals with the potential of mosquito populations, which seems like it could be vast for a country like that.