Cal. Welf. & Inst. Code § 1759

No person placed in such an institution or under such an agency may be released by the institution or agency until after approval of the release by the authority, unless the institution or agency would have power under the law to release at its own discretion persons committed to it by order of a court. In the latter case, it may not release a person placed by the authority until a reasonable time after it has notified the authority of its intention to release him.