CA Land Surveyor common mistakes
CA Land Surveyor · Understand the traps and how to avoid them.
Holding record bearings and distances over the positions of found original monuments, and then 'correcting' the monument to fit the record math rather than correcting the record to fit the monument.
Candidates drill coordinate geometry and inverse computations until the math feels authoritative, so a discrepancy of a few hundredths looks like an error to be eliminated rather than evidence to be weighed. The rules of construction (monuments over courses and distances, natural monuments over artificial, original over subsequent) are memorized as a slogan but not applied when the numbers disagree.
What to do instead
Before computing anything, classify every monument as original, subsequent, or questionable, and write down what each one controls. When record and monument conflict, state in the notes which rule of construction governs and why, then adjust the record geometry to the accepted monument positions. Practise item sets where the 'right' answer is the one that contradicts the inverse.
Reporting distances and coordinates to the millimetre or to 0.001 ft when the instrument specification, the control, or the field conditions only support a few hundredths, and mixing US Survey Foot values with International Foot values without conversion.
Software displays eight decimals by default, and candidates equate displayed precision with real accuracy. The US Survey Foot (0.3048006096 m) versus International Foot (0.3048 m) distinction is a roughly 2 ppm trap that never trips an alarm because the numbers both 'look like feet'.
What to do instead
State the unit convention and the positional uncertainty for every reported value, and round the output to the uncertainty, not to the software default. Check the basis of every record distance and convert explicitly; NGS retired the US Survey Foot as of the end of 2022, so legacy California records must be flagged and converted, not assumed.
Applying the wrong map type threshold, or assuming a tentative map's life and any extensions are fixed, without checking the current statutory period and the applicable extension provisions.
Candidates memorize 'five or more lots equals final map' but then misapply it to condominium conversions, lot line adjustments, or subdivisions where exceptions and local ordinances change the answer. Tentative map expiration is likewise treated as a single memorized number rather than a statutory scheme with tiered periods and automatic extensions.
What to do instead
Build a decision tree keyed to the number of parcels created, the type of division, and any exception (conversions, remainder parcels, mergers). For expiration, cite the governing section and confirm whether an extension applies before concluding a map has lapsed; treat the date of recordation, not approval, as the anchor.
Combining or comparing coordinates without confirming the datum, realization/epoch, zone, and projection are identical, and mixing NAD27 values with NAD83 (or different CCS83 epochs) in a single adjustment.
Coordinate values look interchangeable, and a state plane coordinate in a deed or a control datasheet gives no visual warning that it was derived from a different realization. The shift between realizations is often larger than the tolerance the surveyor is trying to prove.
What to do instead
Record datum, realization/epoch, zone, projection, and units on every control list and every map. Before any combination or comparison, run an explicit transformation and document it; where the epoch of a published coordinate is unknown, treat it as unchecked and re-observe the control.
Assuming a water boundary sits at today's visible water's edge, or treating the ordinary high water mark as a line that can be located by a single field observation, without first establishing whether the water was navigable at statehood.
The water's edge is the most visually convincing feature in the field, so it dominates judgment. Navigability is a legal question fixed at the date of statehood, not a field observation, and candidates skip it because it requires documentary research rather than instrument work.
What to do instead
Address navigability as of statehood from the record (meander lines, government surveys, historical use) before locating any line. Then locate the OHWM from the full set of indicators - ordinary high water marks on trees and banks, soil staining, vegetation change, scour lines - and describe the evidence, not just the picked line.
Going to the field without a completed record search and perimeter reconnaissance, then setting a replacement monument at the first plausible spot without searching for conflicting evidence nearby.
Field time feels like productive time and office research feels like delay, so the search is truncated. Once a candidate has invested effort digging at one location, confirmation bias makes it hard to abandon that hole for a better one fifty feet away.
What to do instead
Complete the title and record chain, compile the monument record, and walk the full perimeter before setting anything. Excavate at every reasonable position indicated by the record, and document each search pit and its result so the absence of a monument is itself evidence.
Applying proportionate measurement to a corner that is original or obliterated, or failing to distinguish a lost corner from an obliterated one before choosing a re-establishment method.
Proportioning is the most rehearsed computation in PLSS problems, so it becomes the default answer whenever a corner is missing. The distinction between lost and obliterated turns on whether evidence of the original position survives, which requires an evidentiary judgment rather than a formula.
What to do instead
Ask first whether any evidence of the original position survives - accessories, bearing trees, pits, disturbed soil, remnant marks. If it does, the corner is obliterated and evidence controls; only a genuinely lost corner is restored by proportion, and then only between accepted corners of the correct figure.
Recording state plane coordinates or grid distances without applying the combined scale factor and meridian convergence, treating grid values as if they were ground values, or vice versa.
The projection is invisible in the field; a total station measures ground distance and the software silently converts. Candidates also forget that convergence rotates the grid azimuth away from astronomic/north-referenced bearings by an amount that grows with distance from the central meridian.
What to do instead
For every coordinate or distance used in a boundary context, state whether it is ground or grid, show the elevation factor, the scale factor, and the combined factor, and show the convergence applied to azimuths. Keep a ground-coordinate working file and a grid working file, and never mix them within one computation.
Subdividing a section into aliquot parts without accounting for the fractional lots in the north and west tiers and the effect of meander corners along a meandered boundary.
Candidates apply the clean 4x4 aliquot grid to every section, but regular subdivision only holds in the interior; the north and west tiers absorb the excess or deficiency, and meandered lines produce fractional lots numbered from the north and west, not full quarter-quarters.
What to do instead
Check the government field notes for the section's actual dimensions and for meander lines before subdividing. Place the fractional lots where the notes and plat put them, carry the excess or deficiency into the north and west tiers, and treat meander corners as controlling the extent of the fractional lots rather than as boundary evidence of the water line.
Moving a boundary with a gradual shift of a river or shoreline in every case, or alternatively freezing every water boundary at the location shown on the original plat, without distinguishing accretion and reliction from avulsion and erosion.
Both errors are comfortable because they replace a hard judgment with a rule: 'always follow the water' or 'always follow the plat'. The distinction is factual - whether the change was gradual and imperceptible or sudden and perceptible - and the field evidence for it is subtle.
What to do instead
Document the character and rate of the change from historical imagery, old surveys, vegetation age, and witness accounts, and classify the event before deciding whether the boundary moved. Gradual and imperceptible change shifts the boundary; a sudden avulsive change leaves the boundary where it was, with the vacated bed following the same principle.