All funds of the board shall be kept separate from the other funds of the city and in the city depository, and the same shall be withdrawn only in such sums and at such times as the same shall be actually required for the expenditures authorized by law, and only upon warrants signed by an employee of the utility designated by the board and countersigned by a member of the board designated by the board, and issued for claims that have been audited and ordered paid by the board and for salaries due board members and employees for work performed and services rendered.
Alabama Legal Code