Indiana Code Title 36. Local Government § 36-7-5.1-5

Sec. 5. (a) The legislative bodies of one (1) or more municipalities (meeting the population and proximity requirements under section 9 of this chapter) and one (1) or more counties may establish, by identical ordinances, a joint district planning and zoning commission. The ordinances must specify the following:

(b) A municipality having a population of more than three thousand (3,000) and less than fifteen thousand (15,000) may pass an ordinance to establish a joint district for any territory that is located:

(c) A municipality having a population of more than twenty-five thousand (25,000) and less than fifty thousand (50,000) may pass an ordinance to establish a joint district for any territory that is located:

(d) When the boundaries of a proposed joint district include real property lying within the corporate boundaries of a municipality, the municipality is subject to the jurisdiction of the joint district and the provisions of this chapter only if the municipality adopts an ordinance under subsection (a).

(e) After the boundaries and duration of a joint district have been established under subsection (a), the boundaries and the duration may not be changed.