Local public improvements may be initiated by petition signed by property owners whose aggregate property in the proposed district was assessed for not less than 51% of the total assessed value of the privately-owned real property located therein, as shown by the last preceding general tax records of the city. The petition shall contain a brief description of the property owned by the respective signatories thereof, and if it shall appear that the petition is signed by at least 51% as aforesaid, the Clerk shall certify same to the City Council. The petition shall be addressed to the City Council and filed with the Clerk and shall in no event be considered directory but is advisory only.