Pursuant to a resolution adopted by its board of supervisors by a four-fifths vote of all of the members of the board of supervisors, a county may appropriate any of its available moneys to a revolving fund not to exceed five hundred thousand dollars ($500,000) to be used by any county sanitation district, county flood control district, or county maintenance district, located wholly within the county for the acquisition of real or personal property, environmental impact studies, fiscal analysis, engineering services, or the construction of structures or improvements needed in whole or in part for district purposes. The revolving fund shall be reimbursed
from service fees, connection charges, tax revenues or other moneys available to the district, and no sums shall be disbursed from the fund until an agreement with a term not exceeding 10 years has been made between the board of supervisors and the governing board of the district encompassing the method by, and the time within, which the district is to reimburse the fund. Reimbursement of the fund from tax revenue shall not exceed in any one fiscal year an amount equal to one cent ($0.01) on the tax rate or twenty-five thousand dollars ($25,000), whichever is less. The district shall reimburse the fund for any amount disbursed to the district within 10 years after disbursement, together with interest at the current rate per annum received on similar types of investments by the county as determined by the county treasurer.