Full Path from The Start of Water Treatment to The Exit
Part #1: Getting to Water Treatment
Go to the safe room on the right and pick up the blue key. Then, go back and find the blue door.
Part #2: Accessing the Yellow Key
Go across the canal and through the offices. You’ll reach an open parking area. Fight across it to find a switch. The switch is in this room. Some players have trouble crossing the electrified canal. You can jump over the canal without any tricks and stand on the grates above the water. If you’re not sure, try sliding forward and jumping during the slide.
Part #3: The Door in Yellow
After using the switch, go back to the offices and down some stairs. A door will be unlocked, and the yellow key is inside. After getting the key, go back out to the yellow door. Once through, click a switch. This switch opens a door in the canal. You can see the switch and the door opening through the glass.
Part #4: Turning off the Generator Featuring Some Platforming
Go back to the canal and walk along the side through the opened gate. In the larger water treatment room, shoot a window and jump through it. Go around the outside of the room and make a few jumps to enter the generator area. Turn it off. Here’s the window you need to shoot and jump through. There’s some easy platforming.
Part #5: Purple Key and Leaving to the Streets
After turning off the generator, the lights will go out. Go back through the treatment area and down the canal. You’ll find a purple key. Take it and go through the loading screen. You’ll find the purple door that lets you leave the area.
I hope the above information was helpful. Happy gaming!
I’m still stuck, even though I tried to follow this. I’m concerned that I might have tripped over a scripted trigger that was meant to unlock the next area because I immediately obtained the purple card key by diving into the electrified water. I’m going to try loading my previous save again to see if that fixes this softlock I’m in.
Never mind, I completely missed the bottom part of Utility Area, feeling pretty silly now 😛