Should the city or town so absorbed or whose government is extinguished own any waterworks, gas or electric light systems, the city or town so altering or rearranging its boundary lines shall take charge of and operate said waterworks, gas or electric light systems on the same terms and conditions and charge the consumers thereof the same rates or charges as before said absorption by the city or town so altering or rearranging its boundary lines, and said city or town shall have the same use and benefit of said waterworks, gas or electric light systems as that of the city or town so absorbed.