So you know you have this tool available. The timeline is small and I do not know how many sigs you would need, but it is a political solution to try alongside any legal solution. If you call the city clerk and ask how many total votes were cast for the office of governor in the city in 2010, then the number of sigs you would need within 30 days after the ordinance is published is 15% of that vote total. If that seems feasible, it is a shot at a popular vote to repeal the new ordinance if they pass it. Further, if you make a credible threat to file such petition NOW then maybe they will not pass the zoning ordinance in the first place. I doubt that they would want a vote on this.
MICHIGAN ZONING ENABLING ACT (EXCERPT)
Act 110 of 2006
125.3402 Notice of intent to file petition.Sec. 402.
(1)
Within 7 days after publication of a zoning ordinance under section 401, a registered elector residing in the zoning jurisdiction of a county or township
may file with the clerk of the legislative body a
notice of intent to file a petition under this section.
(2) If a notice of intent is filed under subsection (1), the
petitioner shall have 30 days following the publication of the zoning ordinance to file a petition signed by a number of registered electors residing in the zoning jurisdiction not less than 15% of the total vote cast within the zoning jurisdiction for all candidates for governor at the last preceding general election at which a governor was elected, with the clerk of the legislative body requesting the submission of a zoning ordinance or part of a zoning ordinance to the electors residing in the zoning jurisdiction for their approval.
(3) Upon the filing of a notice of intent under subsection (1), the zoning ordinance or part of the zoning ordinance adopted by the legislative body shall not take effect until 1 of the following occurs:
(a) The expiration of 30 days after publication of the ordinance, if a petition is not filed within that time.
(b) If a petition is filed within 30 days after publication of the ordinance, the clerk of the legislative body determines that the petition is inadequate.
(c) If a petition is filed within 30 days after publication of the ordinance, the clerk of the legislative body determines that the petition is adequate and the ordinance or part of the ordinance is approved by a majority of the registered electors residing in the zoning jurisdiction voting on the petition at the next regular election or at any special election called for that purpose. The legislative body shall provide the manner of submitting the zoning ordinance or part of the zoning ordinance to the electors for their approval or rejection and determining the result of the election.
(4) A petition and an election under this section are subject to the Michigan election law, 1954 PA 116, MCL 168.1 to 168.992.