All fees and charges received and collected under the authority of this chapter shall be credited to a fund to be designated as the water fund. The accounts of said fund shall show all receipts and expenditures for the administration, maintenance, operation, expansion, upkeep and repair of the domestic water system and any payments into a sinking fund established for the purpose of paying principal of and interest on the water indebtedness of the city, which shall from time to time be outstanding. As provided by law, when budgeted and appropriated, the funds and credits to the account of the water fund shall be available for the payment of the requirements for the maintenance, operation, expansion, repairs and upkeep of the domestic water system of the city, and to the extent legally available, for payment into a sinking fund established for the payment of the principal and interest on any water bond indebtedness of the city which shall from time to time be outstanding. (2003 Code § 9-01-24)