Cal. Water Code § 1430

A temporary permit issued under this article shall not result in the creation of a vested right, even of a temporary nature, but shall be subject at all times to modification or revocation in the discretion of the board. The authorization to divert and use water under a temporary permit shall automatically expire 180 days after the authorization takes effect, unless an earlier date is specified or the temporary permit is revoked. The 180-day period does not include any time required for monitoring, reporting, or mitigation before or after the authorization to divert or use water under the temporary permit. If the temporary permit authorizes diversion to storage, the 180-day period is a limitation on the authorization to divert and not a limitation on the authorization for beneficial use of water diverted to storage.