Cal. Sts. & High. Code § 19031

Proceedings for the formation of a highway lighting district may be instituted by filing, at a regular meeting of the board of supervisors of the county in which the proposed district to be benefited thereby is situated, a petition signed by 15 or more taxpayers thereof or by the owners of taxable property representing 60 percent or more of the total assessed valuation of all taxable property within the proposed district.