On Tue, 19 Nov 2002 16:54:21 EST, Barry Shein said:
Before we get too, too, smug about this if you view the Manhattan skyline, particularly downtown (e.g., SOHO/Tribeca) you'll see house-sized water tanks on many, many buildings, particularly 3-10 story older buildings. I assume due to inadequate water pressure but I honestly don't know why they're there, but they're all over.
They're there only to guarantee enough water pressure to make the sinks work on the 30th floor, and to make sure you have enough water to flush the toilets even if the supply goes belly-up. That's a long way from using it as a power source - take a look at the spillway of a hydro dam sometime. Incidentally, plumbing a high-rise is non-trivial - the naive approach causes a pressure differential of 14PSI for every 32 feet, which means if you have enough pressure to make water come out on the 60th floor, the first-floor bathrooms have 250PSI water. ;)