Cal. Health & Safety Code § 19852

The governing body of a county or city, including a charter city, may prescribe such fees as will pay the expenses incurred by the building department of such city or county in maintaining the official copy of the plans of buildings for which it has issued a building permit, but the fees shall not exceed the amount reasonably required by the building department in maintaining the official copy of the plans of buildings for which it has issued a building permit. The fees shall be imposed pursuant to Section 66016 of the Government Code.