Indiana Code Title 8. Utilities and Transportation § 8-10-5-5.5

Sec. 5.5. Any port authority that is created under this chapter may expand its jurisdiction to include any other unit (as defined in IC 36-1-2-23) that desires to join the expanded authority.  The legislative body (as defined in IC 36-1-2-9) of each unit that is in the authority shall by ordinance determine the number of directors on the board of the expanded authority and any other terms of the expansion that it considers appropriate.  The legislative body of each unit that desires to join the authority shall by ordinance agree to join the authority and to accept the terms of the ordinance that provides for the expansion.