Indiana Code Title 8. Utilities and Transportation § 8-1.5-4-7

Sec. 7. (a) In fixing the proportion of the revenues of the waterworks department required for operation and maintenance, the board shall consider the cost of the operation and maintenance of the waterworks, and may not set aside into the special fund a greater amount of the revenues and proceeds than, in its judgment, is required for the operation and maintenance.

(b) If a surplus is accumulated in the operating and maintenance fund, and that surplus is equal to the cost of maintaining and operating the waterworks system during the remainder of the current calendar, operating, or fiscal year and during the next calendar, operating, or fiscal year, any excess over that surplus may be transferred by the board to either the depreciation account, to be used for any improvements, extensions, or additions to the waterworks, or to the bond and interest redemption account.