California Code, Government Code - GOV § 25260

The board of supervisors may by resolution create one or more working capital funds. The board may make available such amounts as are necessary to establish each fund and to maintain its solvency. At the beginning of any fiscal year the board may provide by resolution for the transfer of any or all of the moneys in any fund created pursuant to this section or for the abolishment of any such fund.

Each working capital fund may be used to finance internal service activities rendered to the various departments and agencies of the county or to the districts governed by the board of supervisors, or to finance those activities performed by the county for any local governmental agency by agreement with the governing body of such agency. The fund may finance (1) equipment, (2) materials, (3) supplies, (4) services, and (5) all expenses incurred in establishing and operating the service activities.

The board may provide for the fixing and collection of charges from the recipients of activities financed by the fund, and such charges may include all expense in providing the service activity, including operational cost and depreciation.

All funds created pursuant to this section shall be accounted for as prescribed by the county auditor or controller.