Pub. Resources Code, § 6360

Notwithstanding any other provision of law, the boundary line of land lying within the Sacramento-San Joaquin Delta (as defined in Section 12220 of the Water Code) bordering upon tidal waters or upon a navigable stream is, for the purpose of determining boundary location, conclusively presumed to be located at the ordinary high-water mark when such land borders on tidal lands not validly patented into private ownership and at the low-water mark when such land borders upon a navigable stream where there is no tide or where such lands consist of tidelands validly patented into private ownership, as such high- or low-water mark exists upon the effective date of this section and from time to time thereafter where, for a period of not less than 30 years continuously, prior to the effective date of this section, the following facts exist:

(a) The land including any accretion thereto has been occupied openly and notoriously by persons claiming title thereto or their predecessors. Land shall be deemed occupied for the purpose of this section when protected by a substantial enclosure; or when usually cultivated; or when improvements have been constructed thereon by the persons claiming such title or their predecessors, including, in the case of improvements located waterward of the landward toe of a levee, that land surrounding such improvements as is incidental to the usual and reasonable use of the improvements.

(b) Taxes (state, county or municipal) have been levied and assessed during such period on such land including any accretion thereto and such persons or their predecessors have paid all such taxes during such period. The requirements of this subparagraph shall be deemed to have been met during any period when the owner or claimant to such land was exempt from ad valorem taxation.

(c) The persons claiming title or their predecessors have based their claim upon a deed or map, or both, describing or depicting the land including any accretion thereto, which deed or map has been recorded in the office of the recorder of the county in which the land is situated.

Nothing in this section shall be construed as vesting in an adjacent or contiguous landowner title to any lands which have been artificially filled by the landowner or his predecessors or any public agency or which have attached to his lands as a result of an avulsive change in the shoreline or as the result of an avulsive change in the course of, or an artifical rechannelization of, any river or stream, or divesting such landowner of any title which he may have to any lands which have been artificially dredged by the landowner or his predecessors or any public agency or which have detached from his land as a result of an avulsive change in the shoreline or as the result of an avulsive change in the course of, or an artifical rechannelization of, any river or stream.