The board of supervisors may, by ordinance or resolution, authorize the county auditor to perform the functions of the board in establishing, increasing, reducing, or discontinuing any of the revolving funds provided for in this article. In the event that the board authorizes the county auditor to perform such functions of the board, the county auditor shall (a) be subject to the same requirements and limitations otherwise prescribed for the board in this article, (b) in lieu of acting by resolution, act by signed statement having the same content otherwise prescribed in this article for resolutions, and (c) render a written report to the board at the end of each fiscal year identifying the revolving funds in existence during the fiscal year, the amount of such fund, and the officer using the fund.