Most apartments in NY pay for their own gas and electric, unless they’re mother-in-law basement/attic marginally legal accommodations.
And as noted above, you wouldn’t be able to get much power from the water stream.
(In Manhattan the biggest of the buildings are on the ConEd steam system but not the smaller ones. For example, the 25-storey building I live in has an oil-burning boiler. All the brownstones have their own boilers. Tapping into the steam system, and the equipment that can use the high-pressure steam, is major infrastructure and not worth the expense for a smaller building.)