Cal. Water Code § 12879.15

Any bonds issued and sold pursuant to this chapter may be refunded by the issuance of refunding bonds in accordance with Article 6 (commencing with Section 16780) of Chapter 4 of Part 3 of Division 2 of Title 2 of the Government Code. Approval by the electors of the state for the issuance of these bonds shall include the approval of any bonds issued to refund any bonds originally issued or previously issued refunding bonds.