In what climate? Will the area be subject to freezing while you are away?
At the least, do turn off the main valve. Do turn off the power or gas to the water heater. Do not drain the heater. Do open all the faucets. Do this even in a warm climate This will offer some protection against freezing damage in cold climates
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Here is a link that might be useful: Tips

this is a cold climate. the water heater is in the basement. the heat will remain on at 55 or greater. we do have a cold sensor in the basement that will warn if heat falls below 40. My concern is not about freezing. we do not plan to drain the pipes or water heater. we will not be turning off gas to the water heater or house.

Turn the water heater down. There should be a 'vacation' or a 'pilot' setting. You don't want it to boil away the water over the 2 months you are gone.