I'm having some trouble mapping this area out. Perhaps someone could help me.
How do you get access to the basement? I believe it's from the staircase since you need to restore the power before activating the elevator. However, I believe that this is only the case for Elza. I have not yet understood if Leon is supposed to gain access to it through the manhole by traveling across the second floor and going outside (like Elza's sewer entrance), or if he gets through the staircase.
Here's what I believe that might be the basement area and respective entrances, and a brief explanation why.
Let's begin with the staircase:
Take a look at the texture and knob of the door. It seems to be the same. Also note that in the second image, there's an emergency(?) exit signal. Now, let's look at the morgue:
Although the placement might seem morbid (next to the staircase?), the door texture matches, and so does the door knob. It seems awkward to have the morgue placed so close to the staircase, especially considering the kennel, firing range and garage are located in the basement. However, the placement doesn't force the officers to go to the morgue. To get to the morgue you take the left after existing the staircase, and travel the corridor to go there. It seems that if you take the right, you get access to the hallway where the power room, armory, firing range and kennel are located.
The power room. Not much to say..
The armory. I can't understand if it's the same hallway as the power room or an entirely new one. However, the lights from above seem to be suspended too, so I think all these locations are placed in the same hallway. From what I understand, the firing range is located next to the armory, so I'll just skip it (I don't believe there's any image of its door in the hallway, but I could be mistaken).
The jail? I'm not sure about this one... I don't think it's the kennel, the door doesn't match its shape, or the firing range's.
Finally, the kennel and the garage. I was under the impression you'd get access to the garage through the kennel, but upon closer inspection, the door knob doesn't match it. The shape is the same, though. Still, it makes me wonder where the second door in the kennel leads to.
I didn't include the service area because I don't know how you gain access to it or where it's located. I believe it's in the basement, but I'm under the impression that it's completely unrelated to every other location found, like off-limits. But I'm probably mistaken. And that's all, I guess.