A counterpart of the petition, setting forth the text of the petition in full, shall be circulated within the proposed boundaries of the district: Provided, That when an incorporated city, or any part thereof, included as a part of the lands within the proposed boundaries of the district and not excluded by reference therein, the naming of the city, and class thereof, and a statement as to what part or all of the lands within said city are to be included within the proposed boundaries of said district, shall be sufficient identification within said petition, and approval of said drainage district formation shall be by election duly called by the governing body of said city for such purpose of approval or disapproval by the qualified voters of the area in said city sought to be included in said drainage district, and if approved by vote, the mayor of said city shall be directed to sign said petition as representative of said land within said city limits and for the total of said lands encompassed therein and if disapproved by the qualified voters therein, the city, or part thereof, shall be excluded from the district.

A duplicate original or a photographic copy of the original petition, with copies of all signature sheets attached thereto, shall be furnished to the county clerk of each county wherein lies a part of the proposed district. All counterparts shall be filed with the secretary of state at the same time and shall be received and treated by him as a single petition. The secretary of state shall determine the sufficiency or insufficiency of the petition on the basis of the information as to the number and qualifications of signers as shown by the verified enumeration filed with the petition. In the making of such findings, the secretary of state shall consider the signature of the mayor of any city which has approved said petition as herein provided as the signature of one landowner. The secretary of state shall endorse his findings and the date thereof on the face of the petition, and shall notify, in writing, the person designated in the petition as the acting chairman of the steering committee of his findings.