Iowa Code § 373.9: Metropolitan council.

1. A consolidated metropolitan corporation shall be governed by a metropolitan council. The council shall consist of an odd number of members, not less than eleven and not more than seventeen. If a vacancy on the metropolitan council occurs more than sixty days before the next general election, the council shall direct the county commissioner of elections to conduct a special election to fill the vacancy until the next general election.

2. Unless otherwise specified in the consolidation charter, the council shall act by a majority vote of the members on the council.