OK, joking aside, why are you grounding to the water heater? I am assuming you are talking about running a GEC to it? If that is the case, it is to go to the water within 5 feet of entry into the building.
If you are grounding the water heater, the circuit that feeds the igniter circuit is permitted to ground the water heater.
If you are referring to installing a jumper between the hot and cold pipes, they will be connected together at the sinks, tubs, showers, washers, dish washers, etc. and it is not required to add another one.