Assume underground metal water service pipe (10ft...) and a ground rod.

Your original statement was:

Metal water piping is bonded to the electrical system grounding
electrodes to ensure that the metal water piping cannot become live,
*not* to provide a ground for the electrical system

The underground water service pipe is REQUIRED by the 250.50 to be
included as a grounding electrode. It has been thus fire was invented.
Bonding requirements under 250.104-A (not 250.80) have been already met
under the more stringent 250.50. The code clearly requires the water
service pipe to be a grounding electrode. The water pipe clearly
provides “A GROUND FOR THE ELECTRICAL SYSTEM.”

If 250.104 was removed, the connection would still have to be made. If
the water service pipe was plastic 250.104 would prevail.

Both Brad and AZNomad said the water pipe was a grounding electode. So
far no one agrees with you.

You said:
The ground rod is the *primary* grounding
electrode, and the water piping is the supplemental electrode.

250.53-D-2. requires a "supplemental" electrode - your ground rod.
The water pipe is clearly superior based on the size of grounding
electrode conductor required for each electrode and by typical earth
resistances.


You said:
You're also wrong about the reason
The NFPA Handbook said the rod was there because the water pipe might be
replaced in the future with plastic with the rod as a "supplementary"
fall-back.


I'm not sure why you're having so much trouble grasping this.

bud--