Originally Posted by theatretch85
Actually thats not a phone line, it runs to unit on the outside of the house that the meter readers can read the meter with. I have yet to see a water meter that connects to your phone line to read the meter. Usually the unit on the outside of the house is near the spigot in the front of the house or gas meter, etc, its usually near an existing opening.
Since the water utilities are municipally owned and the bill comes from the city, each city area is going to have their own system. Up north, it's impossible to put the water meter outdoors in an accessible area, because they would freeze in the winter. Therefore, the water meter is usually located in the basement. In the olden days, the meter reader would knock on your door once a month (or every three months in Minneapolis where I grew up), you'd let them in to do their thing, and ten seconds later, they'd be gone. Obviously, this presented problems for the utilities when nobody was home, so remote displays and automated reading systems were developed.
My dad's houses in Bloomington had the remote displays on the front of the house. The city of Minneapolis installed phone line systems in the 80's that "call home" with a reading once per month. The city of Columbia Heights has electronic devices attached to their meters that respond to a radio signal sent by meter-reader from the street.
So that could be a phone line, it could lead outdoors to a remote display, or it could be an antenna wire.
The gas company has similar remote reading methods for indoor-mounted gas meters, but in the olden days, they sent meter readers to your door as well. (These days, the gasco prefers to mount the meters outdoors--I suppose they've figured out how to make them read correctly in all temperatures.)