(a) Where the main drainage district, of which the proposed subdistrict is to become a part, shall have been organized by a circuit court, the petition for the proposed subdistrict shall be presented to the circuit court and all subsequent proceedings had therein.
(b) Where the main drainage district, of which the proposed subdistrict shall embrace lands lying in another, or other counties, the petition for the organization of the proposed subdistrict shall be filed in the circuit court of the county in which the main district was organized and all subsequent proceedings shall be had in the circuit court.