California Elections Code
A local, special, or consolidated election may be conducted wholly by mail provided that all of the following conditions apply:
(a) The governing body of the local agency authorizes the use of mailed ballots for the election.
(b) The election is held on an established mailed ballot election date pursuant to Section 1500.
(c) The election is one of the following:
(1) An election in which no more than 1,000 registered voters are eligible to participate.
(2) An election on a measure or measures restricted to (A) the imposition of special taxes, or (B) expenditure limitation overrides, or (C) both (A) and (B), in a city, county, or special district with 5,000 or less registered voters calculated as of the time of the last report of registration by the county elections official to the Secretary of State.
(3) An election on the issuance of a general obligation water bond in accordance with Section 12944.5 of the Water Code.
(4) An election of the Directors of the Monterey Peninsula Water Management District as authorized in Section 122 of Chapter 527 of the Statutes of 1977, known as the Monterey Peninsula Water Management District Law.
(5) An election of the Aliso Water Management Agency, or its affected member agencies, pursuant to Sections 13416 and 13417 of the Water Code.
(6) An election of the San Jacinto Mountain Area Water Study Agency pursuant to Sections 13416 and 13417 of the Water Code.
(7) An election of the San Lorenzo Valley Water District pursuant to Sections 13416 and 13417 of the Water Code.
(8) An election or assessment ballot proceeding required or authorized by Article XIIIC or XIIID of the California Constitution. However, when an assessment ballot proceeding is conducted by mail pursuant to this section, the following rules apply:
(A) The proceeding shall be denominated an assessment ballot proceeding rather than an election.
(B) Ballots shall be denominated assessment ballots.