Tony wrote:

I'm in Houston and all municipal water is gravity fed - that is, the
pressure is determined by the height of the water towers. There is
no way for any central location to know directly what the water
pressure is anywhere in the city.

I would think that if they know the pressure at one place, depending
on the elevation they should know what it is everywhere. The
exception being if there is a large demand in one area and not
elsewhere, then they would have a drop in pressure due to
restrictions in the pipes.

That could happen. Last year, my power went out. After fussing a bit, I
stepped outside. There were FORTY TWO pieces of FIRE EQUIPMENT* in front of
my house dealing with an apartment house fire across the street. My
neighbor, who was trying to get home, circled the neighborhood looking for a
way in. She said that every time she got within about three blocks of the
fire, she spotted a pumper hooked up to a fire plug - we guessed wainting
for a call for more water.

Anyway, with all that commotion I didn't notice a drop in water pressure. I
do have, however, a humongous water tower about two blocks from me (and the
apartment house), so I guess if the fire was at the end of the service run,
there might be a drop-off.

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* These 42 pieces of equipment (I counted them) included your ordinary
pumpers, a nozzle truck that could reach up to the 47th floor (the apartment
house was two stories), a visit-god ladder truck that could reach even
higher, supervisor cars, a cascade unit, special operations vans, and a
bus-looking vehicle resembling the one that takes seniors to the neighboring
Indian Casino for a day of gambling labeled "City of Houston Mobile Command
Center." I didn't bother counting the cop cars or ambulances.