The mayor and city council of any city of the second class or the village board of trustees of any village are hereby authorized to issue bonds for the purpose of acquiring title to real estate, as contemplated by sections 17-948 and 17-949, and for the purpose of improving, equipping, and furnishing such real estate as parks and recreational grounds and for the purpose of building swimming pools and dams. No such bonds shall be issued until the question of issuing the same shall have been submitted to the electors of such city or village at a general election therein, or at a special election called for the purpose of submitting a proposition to issue such bonds, and unless at such election a majority of the electors voting on such proposition shall have voted in favor of issuing such bonds. The question of bond issues in such cities and villages, when defeated, shall not be resubmitted in substance for a period of six months from and after the date of such election. Such bonds shall be payable in not exceeding twenty years from their date and shall bear interest payable annually or semiannually.