Just wondering if its possible to do this?

[OriginalUsername]

You could create something like a flooded stairway. Just place a blockbox with a script_area saying he can't go there because it's flooded. The player has to drain this (Like turning a valve) in another room. So when it's turned, it'll deactivate the blockbox, water, and the script_area. The scripting won't be too hard, but you can always ask if you don't understand!