NM Land Surveyor cheat sheet

Priority of evidence in retracement: natural monuments (rivers, lakes, trees) > artificial monuments and original government corners > courses and distances > area or quantity.

Proportionate measurement applies only to lost corners on original GLO lines between existing original corners; it never applies to corners that can be re-established by direct evidence.

A riparian boundary on a meanderable non-navigable stream follows the thread (middle) of the stream; on navigable waters the ordinary high water mark typically governs, subject to New Mexico law and federal title principles.

Ambiguity in a deed is resolved against the grantor (contra proferentem); a call for a monument controls over a call for distance or bearing when the two conflict.

Adverse possession in New Mexico generally requires color of title plus payment of property taxes for the statutory period; boundary-by-agreement and practical location doctrines can also settle disputed lines.

Easement by prescription requires use that is open, notorious, adverse, continuous, and uninterrupted for the statutory period; permissive use defeats the claim.

Monument perpetuation: set durable, referenced monuments (with ties to at least two record corners) and file a record of survey or corner record when re-establishing corners.

Presumption of original location favors undisturbed original monuments over later remonumentation; a disturbed monument is re-established from the best available evidence, not from the nearest convenient position.

New Mexico was part of the Mexican Cession (1848) and Gadsden Purchase (1853); Spanish and Mexican land grants predate the PLSS and carry senior rights that must be researched before any PLSS retracement.

The New Mexico Office of the State Engineer administers water rights and the prior-appropriation doctrine; water rights are separate from land title and are not conveyed automatically with real property unless expressly included.

The New Mexico Professional Surveyors Licensing Board, under the Regulation and Licensing Department, licenses land surveyors; only a licensed surveyor may prepare boundary, cadastral, and subdivision plats for filing.

The New Mexico Subdivision Act and county subdivision regulations govern platting; plats are filed with the county clerk after approval by the appropriate governing body.

New Mexico is a recording state; instruments affecting title are recorded with the county clerk, and priority generally follows recording (race-notice) with exceptions for unrecorded interests and federal patents.

Community property state: separate and community property rules affect how deeds, easements, and rights-of-way are conveyed and how title is held.

The State Land Office manages state trust lands granted at statehood; surveys on trust land require coordination with the Commissioner of Public Lands and may involve leases or easements.

Federal reservation boundaries, national forests, and tribal lands (pueblos and reservations) have distinct survey and jurisdictional rules; tribal trust land surveys require tribal and BIA coordination.

Standard township is 6 miles square containing 36 sections of 1 square mile (640 acres); sections are numbered serpentine from the northeast corner: 1 through 6 east to west, 7 through 12 west to east, and so on.

Standard parallels (correction lines) are run every 24 miles north and south of the base line; guide meridians are run every 24 miles east and west of the principal meridian to control convergence.

Section subdivision: half-section = 320 ac, quarter-section = 160 ac, quarter-quarter = 40 ac; aliquot parts are described by successive halving (e.g., NE1/4 of SW1/4).

Lost corner re-establishment: single proportionate measurement on a line between two known corners; double proportionate measurement for a lost corner interior to two lines (e.g., section corner at intersection of two proportioned lines).

Meander corners are set at the intersection of section lines with meanderable water bodies; the meander line is not a boundary and does not close the area of the fractional section.

Closing corners are set where standard parallels or correction lines intersect section lines; they are not used as controlling corners for proportionate measurement of lost corners on the section line.

Fractional lots along navigable or meanderable waters are numbered and their areas computed from the meander line; lot areas appear on the official plat and control over computed aliquot areas.

The GLO/BLM cadastral survey records (field notes, plats) are the primary evidence for PLSS retracement; original corners are protected by federal law (43 U.S.C. 772) from removal or disturbance.

NAD83 (2011) and the upcoming NATRF2022 (modernized NSRS) are the current and forthcoming horizontal datums; NAVD88 is the current vertical datum, with NAPGD2022 planned.

State Plane Coordinate System in New Mexico uses two zones: New Mexico East (FIPS 3001) and New Mexico West (FIPS 3002), both Lambert Conformal Conic projections.

Map projection scale factor (k) and elevation factor combine to give grid-to-ground: ground distance = grid distance / (k * elevation factor); elevation factor = R / (R + h) with R ≈ 6,371,000 m.

Geoid separation (N) relates ellipsoid and orthometric heights: H = h - N; use the current geoid model (e.g., GEOID18) for conversion.

OPUS and OPUS-RS provide static GNSS-derived coordinates; OPUS projects require sufficient observation duration (typically 2+ hours for long baselines) and proper monument stability.

Geodetic azimuth differs from grid azimuth by the convergence angle (mapping angle); true north, grid north, and magnetic north must be distinguished and declination noted.

Control densification: tie to at least two NSRS CORS or published passive marks, and check closure and residuals against the published accuracy standards (e.g., FGCS standards).

Ellipsoid vs. geoid: GNSS-derived ellipsoid heights must be converted to orthometric heights for most engineering and floodplain work, and datum tags must appear on all deliverables.

Total station: measure horizontal and vertical angles plus slope distance; apply atmospheric (temperature, pressure) and prism constant corrections; slope distance = horizontal distance / cos(vertical angle).

GNSS-RTK accuracy depends on baseline length, satellite geometry (PDOP), and ionospheric conditions; a fixed solution is required for survey-grade positions, and independent checks against known control are mandatory.

Traverse procedures: close on known control, use forced centering, balance sight distances, and record angles to the nearest second; angular closure should be checked against allowable misclosure.

Leveling: differential leveling closes on a benchmark; allowable misclosure is often expressed as C * sqrt(K) where K is loop length in miles or kilometers and C depends on order/class.

Robotic total stations and digital levels reduce systematic error but do not eliminate blunders; redundant observations and independent checks remain required.

Field notes must be legible, in ink or permanent digital form, and include date, party, weather, instrument serial number, and sketches; erasures are prohibited, corrections are struck through and initialed.

Monument setting: use durable materials (rebar with cap, concrete, pipe) and record ties; set at least two reference ties for important corners.

UAV/photogrammetry and terrestrial scanning: ground control points and checkpoints are required; check residuals against project accuracy standards before accepting derived products.

Compass (Bowditch) rule distributes closure error proportionally to line length; transit rule distributes proportionally to latitude and departure magnitudes.

Least squares adjustment minimizes the sum of squared residuals; it requires a stochastic model (standard deviations) and produces residuals, reference factor, and error ellipses.

Traverse closure: linear misclosure = sqrt((Σlatitude)^2 + (Σdeparture)^2); relative precision = total traverse length / linear misclosure.

Latitude = distance * cos(azimuth); departure = distance * sin(azimuth); inverse between two points gives azimuth and distance from ΔN and ΔE.

Error propagation: for a sum, variances add; for a product or function, use partial derivatives (law of propagation of variances).

Standard deviation of the mean = s / sqrt(n); a blunder is detected by residual magnitude relative to the a priori or a posteriori standard deviation.

Coordinate geometry: area by coordinates (shoelace formula); curve formulas - tangent T = R tan(Δ/2), length L = RΔ (Δ in radians), chord = 2R sin(Δ/2).

Units and rounding: carry full precision in computations, round only final values; state units and datum on all reports.

A subdivision plat must show lot lines, dimensions, bearings, curve data (R, L, Δ, chord), dedicated rights-of-way, easements, and the surveyor's seal and certification.

Dedication of streets and public ways requires acceptance by the governing body; until accepted, the dedication is an offer, not a conveyance.

Easement descriptions must identify the burdened and benefited parcels, the location and width, and the purpose; a metes-and-bounds description should close and be tied to a monument or recorded corner.

Rights-of-way: a centerline description with a stated width creates a strip easement; the underlying fee may remain with the abutting owner, and the extent of the interest must be researched.

Blanket vs. specific easements: a blanket easement is not locatable on the ground and may be reformed or located by agreement; specific easements are described by bearing and distance.

Plat vacation and replat require compliance with the subdivision act and local ordinances, including notice to affected parties and approval by the governing body.

Common elements and lot area computations must account for easements and rights-of-way that reduce buildable area; check zoning and setback requirements.

ALTA/NSPS Land Title Surveys follow the current ALTA/NSPS standards and Table A optional items; the surveyor must state the standard and any optional items performed.

Topographic mapping: contour interval should suit the terrain and map scale; spot elevations supplement contours at critical features; vertical accuracy should be stated.

Digital terrain models (DTM/TIN) require breaklines at ridges, valleys, and grade changes; check volumes by comparing end-area and prismoidal methods.

Construction staking: set horizontal and vertical control, compute cut/fill from design grades, and verify with independent checks; as-built surveys document actual conditions.

Horizontal curves: PC, PT, PI, and PCC; vertical curves: PVC, PVI, PVT; parabolic vertical curve elevation = PVC elevation + g1*x + ((g2-g1)/(2L))*x^2.

Slope staking and grade checks: percent grade = (rise/run)*100; convert between percent grade and vertical angle using tan(angle) = grade/100.

Quantity takeoff: end-area method V = L*(A1+A2)/2; prismoidal correction for transition sections; account for shrinkage and swell factors in earthwork volumes.

Floodplain and drainage work requires datum consistency (NAVD88) and compliance with FEMA map standards; elevation certificates must be signed by a licensed surveyor.

Machine control and GPS grading require verified site calibration and periodic checks against independent control.

Scale of a vertical aerial photo = f / H, where f is focal length and H is flying height above ground; larger scale means more detail.

Stereoscopic parallax and the parallax equation (h = H * dp / (P + dp)) allow height determination from overlapping photos.

Ground sample distance (GSD) = pixel size * H / f; smaller GSD means higher resolution.

Aerotriangulation (bundle adjustment) uses tie points and ground control to orient photos; check residuals and report accuracy against ASPRS standards.

LiDAR: point density, classification, and vertical accuracy (RMSEz) must meet project specifications; bare-earth DEMs require ground classification.

Orthophoto production requires a DTM for rectification; orthorectified imagery is planimetrically correct but not a substitute for a boundary survey.

Coordinate reference systems and datum transformations must be documented for all mapping products; misapplied transformations are a common source of error.

Remote sensing indices (e.g., NDVI) and multispectral classification require ground-truth verification before use in engineering or land-cover mapping.

The licensed surveyor is responsible for the work product; sealing and signing a plat certifies personal or direct supervisory review of the work.

Conflicts of interest must be disclosed; a surveyor may not accept compensation from more than one party for the same service without full disclosure and consent.

Standard of care is that of a reasonably prudent surveyor under similar circumstances; errors and omissions insurance and written contracts help manage liability.

Statute of limitations and statutes of repose limit the time to bring claims; the surveyor should retain records for the period required by state law and contract.

Contingent fees based on the outcome of a boundary determination are unethical; fees should be based on scope and effort.

Business forms (sole proprietorship, LLC, corporation) affect personal liability; professional corporations must comply with state ownership and licensing rules.

Written contracts should define scope, deliverables, exclusions, fee, and dispute resolution; change orders document scope changes.

The surveyor must not misrepresent qualifications or stamp work outside their competence or licensure.

Field safety: use high-visibility clothing, traffic control per the MUTCD, and a spotter near heavy equipment; check for utilities before digging (call 811).

Hazard communication and PPE requirements apply to field crews; sun, heat, and wildlife hazards are significant in New Mexico.

Records retention: field notes, computations, and plats should be retained per state law and contract; original field notes are the surveyor's legal record.

New Mexico requires filing of subdivision plats and certain survey records with the county clerk; corner records and monument records should be filed as required by local practice.

Statutory reporting: report boundary disputes, encroachments, and discrepancies to the client in writing; do not conceal material facts.

Federal corner disturbance must be reported to the BLM; removal or destruction of original corners is a federal offense.

Digital data and metadata must be archived with the survey; include datum, projection, units, and software versions.

Incident reporting and documentation protect the surveyor in the event of claims; retain correspondence and field records.