Any city of the second class owning or maintaining a municipal water system may extend its water mains into territory beyond the boundaries of said city for the purpose of supplying water to customers living in territory beyond the city limits of said city, but in territory adjacent thereto, under the following conditions: Whenever a majority of the resident property owners owning more than fifty-one percent of the property to be assessed in territory beyond the city limits of any city of the second class, but adjacent thereto, shall present to the governing body of such city a petition praying for the extension of water mains into said territory, the said governing body of such city shall consider said petition, and if it shall find the extension of said water mains will be of benefit to said city, then the said governing body may, by ordinance, direct the laying and construction of such water mains, together with all the necessary appurtenances into said adjacent territory.