Cal. Government Code § 66638

(a) When the commission, after public hearing, determines that a person or governmental agency has undertaken, or is threatening to undertake, an activity that (1) requires a permit from the commission without securing a permit, or (2) is inconsistent with a permit previously issued by the commission, the commission may issue an order requiring the person or governmental agency to cease and desist. (b) A cease and desist order issued by the commission may be subject to the terms and conditions that the commission may determine are necessary to ensure compliance with this title, including immediate removal of any fill or other material or the setting of a schedule within which steps must be taken to obtain a permit pursuant to this title. (c) Notice of the public hearing on a proposed cease and desist order shall be given to all affected persons and agencies and the order shall be effective and final as to the commission upon issuance thereof. Copies shall be served forthwith by certified mail upon the person or governmental agency being charged with the actual or threatened violation of this title and upon other affected persons and agencies who appeared at the hearing and requested a copy. A copy of the cease and desist order shall also be sent by certified mail to the owner of the property on which the violation occurred.