I dont' really remember much about this game, since I never went back to it after making it (except for using Marion and Helga in A House for Alesa 3), so this information might not be 100% accure and I'd recommend to watch a completed playthrough to see those specific puzzles. But if I recall correctly:
-Bar control room: you need to imput a number painted in blood in the dinning area
-Water zone: after you activiate a switch in the barrel control room, barrels will allow you to get to the generator room
-The battery is used in the generator room
-In order to use the main elevator, you must activate the generator in the generator room
-The generator room is just across the area with water in floor 0