IL Land Surveyor cheat sheet

Priority of evidence in boundary retracement: natural monuments, artificial monuments, courses and distances, then area; written calls generally control over area when they conflict.

A monument is a physical object marking a corner; a corner is a legally established point, which may survive destruction of its monument and be reestablished by evidence.

Adverse possession in Illinois requires 20 years of continuous, hostile, actual, open, notorious, and exclusive possession under claim of right (735 ILCS 5/13-101).

Boundary by acquiescence rests on long, mutual recognition of a line as the boundary, typically coupled with improvement or possession up to that line; it does not require the full 20 years.

Parol evidence may be admitted to explain an ambiguity in a deed or to identify the monument or line called for, but not to contradict an unambiguous written description.

A riparian boundary on a non-navigable stream generally follows the thread (center) of the stream; on navigable waters the state holds title and the boundary is the ordinary high water mark.

Accretion (gradual, imperceptible deposit) adds to the riparian owner; avulsion (sudden, perceptible change) does not shift the boundary.

An easement appurtenant benefits a dominant parcel and burdens a servient parcel; it runs with the land, whereas an easement in gross benefits a person or entity, not a parcel.

Record notice, inquiry notice, and actual notice are the three forms of notice that bind a subsequent purchaser to existing interests in land.

Illinois uses the Torrens system only in limited historic areas; the dominant recording scheme is the county recorder's office under 765 ILCS 5/ (Conveyances Act).

Illinois does not require a mandatory statewide boundary survey map act; plats of subdivision are reviewed under the Plat Act (765 ILCS 205/) by the municipality or county.

The Illinois Professional Land Surveyor Act (225 ILCS 330/) defines the practice of land surveying and is administered by the Illinois Department of Financial and Professional Regulation (IDFPR).

A written description must close; compute closure and report the ratio of error, and never silently adjust a record description to force closure without documenting the basis.

Illinois is a metes-and-bounds and PLSS state; the Third Principal Meridian governs most of the state, with the Fourth Principal Meridian affecting a western area.

Section subdivision by the PLSS: half-sections 320 acres, quarter-sections 160, quarter-quarter 40; aliquot parts are described by repeated halving.

When a deed calls for a monument and a distance that disagree, the monument generally controls unless the monument is shown to be in error or misplaced.

Illinois recording statutes are notice-type; an unrecorded conveyance is void as to subsequent creditors and purchasers without notice (765 ILCS 5/30).

A surveyor's certification on a plat or description must be signed and sealed; the seal may be applied electronically only under IDFPR rules for digital signatures.

State Plane Coordinate System in Illinois: NAD83 uses Illinois East (zone 1201) and Illinois West (zone 1202), Lambert Conformal Conic projections.

Scale factor = grid distance / ground distance; combined factor = grid scale factor × elevation factor, where elevation factor ≈ R / (R + h).

Grid azimuth differs from geodetic azimuth by the convergence angle, which grows with distance from the central meridian and with latitude.

NAD83 (2011) and the forthcoming NATRF2022 differ in realization; mixing epochs or realizations introduces datum shift errors in coordinates.

Ellipsoid vs. geoid: ellipsoid heights (h) and orthometric heights (H) relate by H ≈ h − N, where N is the geoid separation.

Traverse closure: linear misclosure = sqrt((ΣΔE)² + (ΣΔN)²); precision ratio = total traverse length / linear misclosure.

Differential leveling misclosure is distributed proportionally to the length of each sight or setup, not equally per setup, unless setup distances are equal.

GPS/GNSS baseline vectors are referenced to the antenna phase centers; antenna height measurement errors propagate directly into derived elevations.

Map scale: a 1:24,000 map has 1 inch = 2,000 feet; horizontal ground distance = map distance × scale denominator.

Licensure in Illinois requires meeting education, experience, and examination requirements under 225 ILCS 330/ and IDFPR rules (68 Ill. Adm. Code 1270).

Continuing education for Illinois PLS licensure is required each renewal cycle under IDFPR rules; verify current hour and subject requirements with IDFPR before renewal.

A licensee may practice only in areas of competence and must not seal work not prepared or directly supervised by the licensee.

Confidential client information may not be disclosed without consent except as required by law, subpoena, or to prevent a crime or fraud.

Conflicts of interest must be disclosed in writing; a surveyor may not accept compensation from two parties for the same service without disclosure.

Illinois requires reporting of professional misconduct to IDFPR; grounds for discipline include fraud, incompetence, and aiding unlicensed practice.

A professional land surveyor may not practice architecture or engineering beyond the scope of surveying licensure; joint practice requires appropriate licensure.

Retention of survey records and field notes should follow IDFPR and client contract requirements; records are the basis for defending boundary decisions.

Advertising must be truthful and not misleading; use of the title 'Professional Land Surveyor' or 'PLS' is restricted to licensees.