As an alternative to the functions of the county treasurer and the county auditor provided in this chapter, the board may elect to disburse funds of the district. Such election shall be made by resolution of the board and the filing of a certified copy thereof with the county treasurer. The county treasurer shall thereupon deliver to the district all funds of the district. Such funds shall be deposited by the board in a bank or banks approved for deposit of public funds and shall be withdrawn only by written order of the board, signed by the president and secretary. The order shall specify the name of the payee, the fund from which it is to be paid and state generally the purpose for which payment is to be made. Such order shall be entered in the minutes of the board. The board shall appoint a treasurer who shall be responsible for the deposit and withdrawal of funds of the district. The treasurer shall deposit with the district, prior to October 1 of each year, a surety bond in an amount annually fixed by the board. The deposit and withdrawal of funds of the district shall thereafter be subject to the provisions of Article 2 (commencing with Section 53630), Chapter 4, Part 1, Division 2, Title 5, of the Government Code. Any district electing to disburse funds pursuant to this section shall file with the board of supervisors an annual audit of such disbursements which meets the approval of the board of supervisors.