California Code, Public Resources Code - PRC § 6323

If accretions are caused or occasioned by any such structure authorized hereunder, no fence, building or other structure of any kind, other than the structure so authorized and appliances for the protection of life and public recreation, shall be permitted or suffered to be erected or maintained either by the State or by any political subdivision or municipality, or by any one claiming under or through them, upon any such accretions belonging to others than the littoral owner, to the end that all such accretions shall at all times be and remain an unobstructed and open beach, except as provided in Article 3 of this chapter.