if this is metered, have your plumber arrange with your water company
to change the meter which is probably not the culprit. he can check the
system for leaks and also replace all old main shutoffs with new full
throttle opening lever operated water ball valves to permit easy
shutoffs for the repairs or replacement of blocked stop-and waste
valves [replace with ball valves] and clogged elbows and clogged
fixtures. also consider an upgrade to 3/4" from 1/2" copper to improve
water flow throughout the home.
depending on your climate and the positioning of the water lines, if
there is no water meter because you are flat rate or on a well you
could use an inexpensive screw on water pressure meter with adapters to
the aerators of the fixtures to see if you have an unseen leak. listen
for pipe noise with stethoscope. or just let the plumber do it all, the
more experience and age the better. take out all aerators and
showerheads, run water while banging on all pipe elbows if galvanized
to knock any buildup loose but carefully to use large hose cock opened
starting the bang it thru at rear of house first to let out large
debris.
measure the pressure and the gallon flow, both determine how much water
comes thru the rear yard hose and to each device.


Marc wrote:
I have high water pressure at the front yard spigot, however, the
pressure drops substantially inside the house and even further at the
rear yard spigot. I have checked the house water filters and unit,
they are clean and fully functioning. I have replaced the water
pressure control valve in the front as well. The house is on a slab
and there is no evidence of a leak. Any ideas as to the source of the
problem?