Indiana Code Title 8. Utilities and Transportation § 8-1.5-4-8

Sec. 8. (a) The fixed proportion set aside for the payment of the principal and interest of the authorized bonds shall, from month to month, as accrued and received, be set apart and paid into a special account identified as “the bond and interest redemption account”.

(b) In fixing and determining the amount that is to be set aside for the payment of the principal and interest of the authorized bonds, the board may provide that the amount to be set aside and paid into the bond and interest redemption account for any year or years should not exceed a fixed sum, which must be at least sufficient to provide for the payment of the interest and principal of the bonds maturing and becoming payable in each year, together with a surplus or margin of ten percent (10%) in excess.

(c) If a surplus created in the bond and interest redemption account exceeds the interest and principal of any bonds becoming payable during the current calendar, operating, or fiscal year and during the next calendar, operating, and fiscal year, the board may transfer any excess over the surplus to either the operation and maintenance account, or the depreciation account, as the board may designate.