Indiana Code Title 36. Local Government § 36-9-25-29

Sec. 29.  (a) In order to raise money to pay all bonds issued under section 27 of this chapter, including interest, and except as set forth in subsection (c), the board shall levy each year a special tax upon all the property of the district, to meet and pay the principal of the bonds as they mature, together with all accrued interest.  The board shall have the tax levied each year certified to the municipal fiscal officer and to the auditor of the county in which the district is located by October 1.  The tax as levied and certified shall be estimated and entered upon the tax duplicate by the county auditor.  The tax shall be collected and enforced by the county treasurer in the same manner as state and county taxes are estimated, entered, collected, and enforced.

(b) As the tax is collected by the county treasurer, it shall be accumulated and kept in a separate fund to be known as the sanitary district bond fund.  It shall be applied to the payment of the bonds and interest as they mature and not to another purpose.  All accumulations of the fund before their use for the payment of the bonds and interest shall be deposited with the depository or depositories of other public funds in the municipality.  The fund may also be invested as other funds are invested.  In determining the amount of levy necessary for this section, the board shall consider the amount of revenue, if any, to be derived from the collection of fees for sewage treatment service above the amount of revenues necessary to be applied to the operation, maintenance, and administrative expenses of the district.

(c) In lieu of making a levy under this section, or to reduce the amount of the levy, the board may set aside, by resolution, the revenues of the district to be collected before the maturity of the principal and interest of the bonds payable in the following calendar year.  If the board adopts the resolution, then the board may not use any part of the amount set aside out of the revenues for any purpose other than the payment of the bonds and interest.  A proportionate payment of the amount shall be made to the bond fund monthly.