California Code, Water Code - WAT § 1410

(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.