Cal. Pub. Util. Code § 31403

The notice shall contain the substance of the terms and conditions fixed by the board of directors, as provided in Section 31401. Such election shall be conducted and the returns thereof canvassed in the manner provided by law for elections in such city or county as the case may be. If the proposition shall receive the affirmative vote of a majority of electors voting thereon at such election, the governing body of such city or the board of supervisors of the county shall certify the result of such election on the proposition to the board of directors of the district, together with a legal description of the boundaries of the corporate area of such city as of the date of the election, or the boundaries of such unincorporated county territory, accompanied by a map or plat indicating such boundaries.