While it was a common practice to ground a single family dwelling electrical system on the metallic piping (copper or galvanized) of the water service pipe on your property, City staff are warning to use caution with repairs.
With replacements or on-site water service pipe upgrades, the piping material currently used is non-metallic (PEX, Poly Ethylene, Municipex). If your electrical system was formerly grounded to the water service pipe it may no longer be properly grounded with this change in piping material. This adversely affects your electrical system and can affect city water meters.
If you have, or are planning to, repair, replace or upgrade your water service pipe it is advised to contact an electrical contractor to review how your electrical system is grounded.