Cal. Water Code § 1410

(a) There shall be cause for revocation of a permit if the work is not commenced, prosecuted with due diligence, and completed or the water applied to beneficial use as contemplated in the permit and in accordance with this division and the rules and regulations of the board. (b) A permit may be revoked upon request of the permittee or under either of the following procedures: (1) If, after a hearing on a petition for extension of time to complete a project and apply water to beneficial use, the board finds that cause exists to revoke the permit, the board may revoke the permit. (2) If, after an investigation other than a hearing on a petition for extension of time, it appears that cause exists to revoke a permit, the board shall give notice of proposed revocation in writing, mailed in a sealed, prepaid postage and certified letter to the permittee at his or her last known address. If the permittee fails to request a hearing with the time provided under Section 1410.1, the board shall revoke the permit and declare the water subject to appropriation. After a hearing, when a hearing is requested by the permittee pursuant to Section 1410.1, the board may, upon a finding that cause exists, revoke the permit and declare the water subject to appropriation.