California Code, Streets and Highways Code - SHC § 27195

(a) The district shall contract with a certified public accountant or public accountant to make an annual audit, the scope and content of which shall be prescribed by such accountant, of the books, accounts, records, papers, money, and securities of the district.

(b) Such report shall include a statement as to whether or not the accountant, through the application of auditing tests and other auditing procedures, is satisfied that expenditures and claims were supported by proper documentation and were properly recorded.

(c) All costs of the audit shall be borne by the district.

(d) A copy of each year's audit shall be sent to the county auditor of each county within the district for public inspection.