Indiana Code Title 8. Utilities and Transportation § 8-1.5-2-13

Sec. 13. A contract made by the municipal legislative body for the acquisition, construction, extension, or replacement of the property of a public utility must be authorized by ordinance.  The ordinance must provide for the principal and interest of bonds issued for the payment of the cost of the acquisition, construction, extension, or replacement to be paid exclusively from the income and revenue of the property acquired with the proceeds of the bonds.