The county treasurer shall pay out money of the district only upon warrants of the county auditor drawn upon the order of the board of directors of the district signed by the chairman or vice chairman and attested by the secretary or assistant secretary. The county treasurer, with the approval of the board of supervisors, shall pay out the money of the district upon one master warrant of the county auditor drawn upon the order of the board of directors of the district and signed by the chairman or vice chairman and attested to by the secretary or assistant secretary, to meet the district’s expenses, including salaries, at such intervals as is approved by the board of supervisors. The county treasurer shall report in writing on the first day of July, October, January, and March of each year, to the board the amount of money he then holds for the districts, the amount of receipts since his last report, and the amounts paid out. Each such report shall be verified and filed with the secretary of the district to whom it is addressed.