§ 50.11 RECORD KEEPING; AUDIT.
   The city treasurer shall establish proper systems of accounts and shall keep proper books, records, and accounts, in which complete and correct entries shall be made of all transactions relative to the combined waterworks and sewerage system, and at regular annual intervals he shall cause an audit of the books to be made by an independent auditing concern, to show the receipts and disbursements of the combined waterworks and sewerage system.
('69 Code, § 20-10)