AL Land Surveyor cheat sheet

Retracement follows the footsteps of the original surveyor; it does not create new boundaries, only locates existing ones.

Order of evidence (federal/AL practice): natural monuments, then artificial monuments, then courses and distances, then area or quantity.

A call for an adjoiner (a named owner or deed line) generally controls over a call for distance or area.

Senior rights rule: the earlier conveyance of a parcel controls over a later conflicting conveyance from the same grantor.

Adverse possession in Alabama requires 10 years under color of title (Code of Ala. §6-5-200 et seq.); 20 years without color of title.

Water boundary: mean high-water mark is the boundary for tidal waters; ordinary high-water mark for non-tidal navigable streams (varies by state; check AL).

Proportionment: excess/deficiency is distributed pro rata among the courses of a line when monuments at the ends control.

Bearing basis must be stated on the plat; record bearings are typically referenced to a stated monument or grid north.

Alabama plat must be approved by the governing body (county commission or municipality) and recorded in the probate office before lots can be conveyed.

Minimum lot area, width, frontage, and setback are set by local zoning; the plat must conform to the zoning ordinance.

Street right-of-way dedication is shown on the plat; fee title typically passes upon recording and acceptance.

Plat must show north arrow, scale, vicinity map, owner's certificate, surveyor's certificate, and dedications/notes.

Curve data for each lot line: show R, Δ, L, chord bearing and distance, and arc length.

Lot corners are set with monuments (typically 5/8-in rebar with cap or as specified by local standards).

Cul-de-sac and corner-lot geometry must satisfy access and frontage requirements; flag lots require special approval.

Outlots, common areas, and drainage easements are delineated as separate parcels on the plat.

An easement appurtenant benefits a dominant parcel and burdens a servient parcel; it runs with the land.

An easement in gross benefits a person or entity rather than a parcel (e.g., utility easement).

Prescriptive easement in Alabama requires use that is open, notorious, adverse, continuous, and exclusive for the statutory period (20 years generally).

An easement by necessity arises when a parcel is landlocked; it terminates when the necessity ends.

A right-of-way is an easement for passage; the underlying fee remains with the servient owner unless dedicated in fee.

Encroachments (fences, structures) are located by survey and documented; they may create prescriptive rights if not addressed.

Easement width is measured perpendicular to the centerline unless the document specifies otherwise.

Termination of easement: merger, abandonment, release, or expiration of purpose.

NAD83 (2011) is the current horizontal datum for Alabama; NAVD88 is the vertical datum.

SPCS Alabama zones: East (0101), West (0102); scale factor = grid distance / ground distance.

Combined factor = grid scale factor × elevation factor; elevation factor ≈ R/(R+h) where R is earth radius.

State plane coordinates are in meters or US survey feet; note the unit on the plat.

OPUS/static GPS requires occupation times and baseline processing; report in the appropriate realization (e.g., NAD83(2011)2010.00).

Leveling: differential leveling loop closure tolerance is typically expressed as C√M (mm) where M is distance in km.

Control points must be tied to at least two published NGS or state control monuments for horizontal and vertical.

Geoid model (GEOID18) converts ellipsoid heights to orthometric heights for NAVD88.

Contour interval is chosen by scale and terrain; typical 1 ft for 1"=50' or larger, 2-5 ft for smaller scales.

Index contours are every fifth contour and are labeled with elevation.

Spot elevations supplement contours at flat areas, drainage structures, and critical features.

Horizontal accuracy standard for mapping is typically 1/30 inch at map scale (ASPRS Class 1).

Vertical accuracy for contours: one-half contour interval (ASPRS Class 1).

Breaklines define ridges, swales, and pavement edges; TIN surfaces honor breaklines.

Planimetric features include buildings, roads, utilities, fences, and vegetation limits.

Benchmark elevations on the survey should reference NAVD88 and be tied to a published monument.

Horizontal alignment: station = distance along centerline; PC, PI, PT, and PCC/PRC for compound/reverse curves.

Curve formulas: T = R tan(Δ/2); L = RΔ(π/180); LC = 2R sin(Δ/2); M = R(1−cos(Δ/2)); E = R(sec(Δ/2)−1).

Vertical curve: elevation = PVC elev + g1·x + ((g2−g1)/(2L))·x²; high/low point where dy/dx = 0 → x = −g1·L/(g2−g1).

Cut/fill = existing ground elevation − design elevation; positive = fill, negative = cut (or as project convention).

Slope staking: horizontal offset = slope ratio × vertical difference; batter boards and hubs set to grade.

As-built surveys compare constructed features to design; tolerances per project specifications.

Grade stakes show cut/fill and reference to a hub; laser/GNSS grading uses machine control tied to site control.

Temporary benchmarks and control must be protected and re-verified periodically during construction.

Traverse closure: linear error = √(Σdep² + Σlat²); relative precision = closure / perimeter.

Latitude = distance × cos(bearing); Departure = distance × sin(bearing).

Coordinate inverse: bearing = atan2(ΔE, ΔN); distance = √(ΔE² + ΔN²).

Area by coordinates (shoelace): 2A = Σ(Xi·Yi+1 − Xi+1·Yi); take absolute value and divide by 2.

Triangle area: A = ½ab·sin(C); Heron's formula for three sides.

Curve: chord bearing = tangent bearing ± Δ/2; deflection angle per station = Δ/2 per half-station.

Error of closure in angles: sum of interior angles = (n−2)·180°; distribute misclosure equally.

1 acre = 43,560 ft²; 1 mile = 5,280 ft; 1 rod = 16.5 ft; 1 chain = 66 ft.

A surveyor's duty is to the public and to the standards of practice; seal and signature certify the work.

Conflict of interest: disclose any financial interest in the property being surveyed.

Surveyors may not practice law; they report facts and let courts or attorneys resolve boundary disputes.

Boundary surveys should be performed under a written contract defining scope, standards, and deliverables.

Confidentiality of client information is required except where disclosure is compelled by law or court order.

Negligence in boundary location can lead to liability; errors and omissions insurance is standard.

Statements of fact on plats (monuments found/set, acreage, bearings) must be accurate and supported by field evidence.

Professional courtesy: notify adjoining surveyors when retracing their work and record discrepancies.

Alabama Board of Licensure for Professional Engineers and Land Surveyors regulates licensure; continuing education required (typically 15 PDH per renewal cycle; verify current rule).

Land surveyor licensure: education, experience (typically 4 years progressive), and passage of the NCEES FS and PS exams plus Alabama law exam.

Surveyor's seal: must include name, license number, and the words 'Professional Land Surveyor' or 'Land Surveyor'.

Plats must be signed and sealed by the licensed land surveyor responsible for the work and recorded in the probate office.

Alabama requires a written contract for surveying services and disclosure of the surveyor's license status.

Unlicensed practice or use of title 'land surveyor' is prohibited and subject to Board discipline.

Alabama Code Title 34, Chapter 11 governs engineers and land surveyors; Board rules are in Ala. Admin. Code Chapter 330-X.

Corner recordation: Alabama allows recording of corner records/monument records with the probate office for boundary evidence.