The governing board of a school district may, by resolution entered upon its minutes, establish a revolving fund for the purpose of meeting necessary current expenses connected with student activities as defined by this article. The amount of the revolving fund shall be determined by the governing board which establishes the fund and provision for its establishment shall be included in the budget. The amount of monies provided in the revolving fund shall, at the end of each fiscal school year, be returned to the credit of the school district and the fund reestablished as provided in this section.