The city manager shall prepare and submit to the council, not later than April first (1st) of each year, an annual operating budget estimate for the following fiscal year, and a budget message. The operating budget submitted by the city manager must be balanced, as defined in this section as current year expenditures covered by current year revenues. The operating budget estimate shall cover and appropriate for all expenditures of money, including contract and other commitments, except appropriations for expenditures from bond construction funds and special assessment construction funds. The council may amend the budget estimate at any time prior to adoption. [Ord. 17-43 § 2; Ord. 10-03 § 2; Ord. 07-06 § 2; Ord. 04-29 § 2; Ord. 161 § 2, 1985.]