There were the levers to close the gates bridges:
Those two were to open/close Mintwalin entrance:
(if you ever wondered what that niche there was for, it's a reminiscence from the ancient times)
And here was supposed to be a lever to close Dwarven Bridge:
Though I believe the last one was never put in game. That is because the coordinates of the bridge in the script don't really match, even taking into account it was flat originally (according to the script, the bridge had to be way more to the north). The placement of a lever itself seems a bit strange too. I guess the script was related only to some early version of Kazordoon that wasn't in game, but their internal test server probably. Might be wrong though.