water pressure

So I've only had a dribbling of water pressure for the last 4 days. This was one of the reasons I needed to get my haircut, so I could get my hair washed. I called about it after day 2 and was told there was a broken pipe somewhere in the building. At day 4 I called again. A fix-it guy came to the apartment and asked me a lot of questions in Chinese (after putting little plastic booties on to not contaminate my floor with his cooties). I walked to the tub with him and turned the water on and said 'bo how' (no good). He walked back out of the apartment telling me what the problem was in chinese. He opened a little cabinet door in the hallway outside my apartment and flipped a switch. We came back in the apartment and everything worked fine. I haven't checked yet to see if the switch is labeled 'if you want normal water pressure, flip this switch'. And what exactly is that switch doing to raise or lower my water pressure. My engineering mind is curious, but I have a sneaking suspicion I will never find out and even if I did I wouldn't believe the answer.
I also got my 100 RMB's money worth last night at the Germany/Argentina match at the hotel Beer Garden. Turns out there are a lot of Germans living in this town and only one dude from Argentina. He had a rough night.