14.1 Tidal and Non-Tidal Water Boundaries

The January 2025 California Professional Land Surveyor test plan tests water boundaries (tidal datums, navigable versus non-navigable) as Domain IV knowledge D. Independent OpenExamPrep teaching in this section is for the analysis step: you already have the deed, the meander, and the field shore. Now you have to decide which legal line those facts support. A recovered 1870s meander that never mentions a tide station is research, not a finished boundary.

Civil Code 830: three default rules

Civil Code 830 is the statute to parse first. The current text, last amended in 1873–74, reads: except where the grant under which the land is held indicates a different intent, the owner of the upland, when it borders on tide water, takes to ordinary high-water mark; when it borders upon a navigable lake or stream, where there is no tide, the owner takes to the edge of the lake or stream, at low-water mark; when it borders upon any other water, the owner takes to the middle of the lake or stream.

Three clauses, three water types:

• Tide water: upland fee stops at ordinary high-water mark.
• Navigable, nontidal lake or stream: upland fee runs to low-water mark.
• Non-navigable (any other) water: upland fee runs to the thread, the middle of the lake or stream.

The opening clause is a grant-construction limit, not throat-clearing. A patent, a legislative tideland grant, a pierhead or bulkhead line, or a quiet-title judgment can fix a different boundary. Read the writings. Apply 830 only when they do not show a contrary intent.

Civil Code 670 states the State's side of the same pair. The State is the owner of all land below tide water, and below ordinary high-water mark, bordering upon tide water within the State; of all land below the water of a navigable lake or stream; of property lawfully appropriated to its own use; of property dedicated to the State; and of property of which there is no other owner. Together, 670 and 830 are the default fee picture: upland to the 830 line, sovereign bed and tidelands waterward of that line, except as a particular grant says otherwise.

Ordinary high water, mean high tide, and the tidelands trust

Ordinary high-water mark is the Civil Code term. It is a legal line. It is not the wet-sand edge you photographed at 4 p.m. on a spring tide. The California State Lands Commission has exclusive jurisdiction over ungranted tide and submerged lands and is the successor to the Surveyor General and the Division of State Lands (Public Resources Code 6216 and 6301). The Commission is the recognized authority for locating ordinary high water in California. Public Resources Code 6357 authorizes the Commission to establish ordinary high-water mark or ordinary low-water mark by agreement or quiet-title action. Public Resources Code 6308 makes the Commission a necessary party to any title or boundary action involving granted tide and submerged lands.

The United States Supreme Court in Borax Consolidated, Ltd. v. Los Angeles (1935) 296 U.S. 10 held that in tidal areas the boundary is located by identifying the intersection of the mean high tide line with the shore. The State Lands Commission applies that holding with NOAA's mean high water (MHW) tidal datum in the vicinity of the lands. NOAA defines MHW as the average of all high-water heights observed over the National Tidal Datum Epoch (NTDE). NOAA currently publishes that epoch as 1983 through 2001. Mean higher high water (MHHW) is a different, higher datum: the average of the higher high water of each tidal day. Using MHHW as if it were the upland/tideland fee line is a standard miss. So is treating the last high-tide wrack line, a day's wet-sand edge, or a vegetation contour as a substitute for a datum-based mean high tide survey.

The Commission's water-boundary guidance is operational. A watermark on a beach is not the boundary. Surveys taken on separate days may plot an ambulatory line in different places. In areas unaffected by fill or artificial accretion, ordinary high water and the mean high tide line are generally the same. For an ambulatory mean-high-tide-line survey, Commission staff directs surveyors to use the published MHW elevation from the nearest appropriate NOAA tide station or a justified interpolation between adjacent stations; to use the current tidal epoch (1983–2001); to keep the elevation datum the same as the tidal datum (staff currently points to NAVD88); and to hold local published tidal bench marks rather than inventing a local sea-level plane.

The public trust is an overlay, not a second secret fee line you sketch by instinct. California took tidelands, submerged lands, and the beds of navigable waters at statehood to hold for public purposes that began with commerce, navigation, and fisheries. Ungranted tidelands remain subject to that trust. Legislative grants to cities and ports are typically still burdened by trust uses. On the open coast, lands waterward of ordinary high water are the trust lands the Commission manages. A mean-high-tide-line survey locates a fee boundary. It does not, by itself, extinguish trust or public-access questions that sit on that line.

Navigable nontidal water and any other water

The second clause of Civil Code 830 is the inland navigable rule: no tide, but a navigable lake or stream, so the upland owner takes to low-water mark. County of Lake v. Smith (1991) 228 Cal.App.3d 214 read that phrase against the rest of 830 and rejected the claim that low-water mark means the lowest stage the lake has ever reached. Ordinary low water is the working concept, not a historic drought extreme.

Fee to low water is not the whole public story. In State of California v. Superior Court (Lyon) (1981) 29 Cal.3d 210, and in the companion Fogerty decision on Lake Tahoe, the California Supreme Court confirmed that on nontidal navigable waters private fee may run to low water while a public trust easement still burdens the shorezone up to ordinary high water. Keep those two lines separate in the analysis: a low-water fee line under 830, and a high-water trust easement under Lyon and Fogerty. Painting a single State line through a Sierra lake is how the analysis fails.

The third clause is the non-navigable default: the owner takes to the middle of the lake or stream. Adjacent owners meet at that thread unless the grant says otherwise. Navigability for title is a legal conclusion with a historical factual basis. It is not whether a drift boat can run the reach this spring. If the research file does not resolve navigability, say so. Do not promote a private creek into a sovereign bed because the water looks wide in March.

Accretion, reliction, erosion, and avulsion

Civil Code 1014 and 1015 are the accession statutes that test whether the water boundary moves.

Civil Code 1014: where, from natural causes, land forms by imperceptible degrees upon the bank of a river or stream, navigable or not navigable, either by accumulation of material or by the recession of the stream, such land belongs to the owner of the bank, subject to any existing right of way over the bank. That sentence is accretion (alluvion builds) and reliction (water recedes, land appears). Gradual erosion is the loss counterpart: an ambulatory water boundary typically follows the gradual wearing away of the bank. The 1014 trigger is natural causes and imperceptible degrees, not a weekend cutbank after one storm.

Civil Code 1015 is avulsion: if a river or stream, navigable or not navigable, carries away, by sudden violence, a considerable and distinguishable part of a bank, and bears it to the opposite bank, or to another part of the same bank, the owner of the part carried away may reclaim it within a year after the owner of the land to which it has been united takes possession thereof. Sudden, identifiable ground. Title does not quietly migrate with the new channel the way gradual accretion does. The one-year reclaim window is in 1015. Do not replace it with the five-year period from the adverse-possession statutes.

California also distinguishes artificial accretion. State of California ex rel. State Lands Commission v. Superior Court (Lovelace) (1995) 11 Cal.4th 50 restated the general 1014 rule that accretion goes to the upland owner, and it kept California's exception that accretion caused by artificial structures in the water is not treated as a private windfall against the State. The Court looked at the artificial nature of the cause, not every grain of historic mining debris that eventually washed downstream. Fill, groins, and harbor works that manufacture new dry land against sovereign water are the fact pattern that should send you to the Commission, not to a quiet assumption that 1014 just created a new lot.

Where a court or a Commission agreement has fixed ordinary high water, the line is no longer ambulatory. Everywhere else, a mean-high-tide-line survey is a snapshot. Report the date, the station, the epoch, the vertical datum, and the method. Domain IV is asking you to evaluate that evidence against the grant, not to freeze a beach with one GNSS point and a story.

Exam traps. Do not swap MHHW for MHW. Do not call today's wrack line the ordinary high-water mark. Do not treat Civil Code 830 as optional because you recovered a meander. Do not apply the five-year adverse-possession clock to a Civil Code 1015 avulsion claim. Do not assume every inland lake is non-navigable, or that every wide slough is tide water, without the grant, the tide, and the navigability facts.