Sub-metering for water on mulifamily

[Ardel Alegre]

Just got under contract for my first investment property! The property does not come with submetering for water. Is it best to install a submeter, and how much does that usually cost? I also read somewhere that there may be some monthly fee to get someone to go out to the property to read and reset the meter. Is this true? Or is it normal to just charge some flat rate on top of the rent for water?