CO Land Surveyor flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Rule of monument priority

Federal and common-law rule: natural monuments prevail over artificial monuments, which prevail over courses and distances, which prevail over area. The intent of the original parties controls.

Retracement versus resurvey

A retracement re-establishes the location of an existing boundary from record and field evidence. A resurvey creates a new or corrected description; it does not move the original legal line.

Adverse possession period in Colorado

Colorado requires 18 years of actual, adverse, open, notorious, exclusive, and continuous possession. The claimant must show the statutory elements; payment of taxes is evidence, not a separate element.

Prescriptive easement period

An easement by prescription in Colorado requires 18 years of adverse use that is open, notorious, and continuous, similar to adverse possession but granting use rather than title.

Easement by necessity

Arises when a parcel is landlocked by unity of title and strict necessity at the time of severance. Convenience alone does not create the easement, and it ends when necessity ends.

Deed ambiguity construction

Ambiguities in a deed are construed against the grantor. A call for a monument generally controls over a call for distance or area when the two conflict.

Township and section layout

A township is 6 miles square with 36 sections of 640 acres each. Sections are numbered from 1 at the northeast corner, proceeding west then east in alternating rows to 36.

Standard parallels and guide meridians

Standard parallels (correction lines) are run generally every 24 miles north of the base line, and guide meridians every 24 miles east or west of the principal meridian, to limit error accumulation.

Closing corner

A corner established where a surveyed line closes on a previously established line. It may not fall at the midpoint of the line it closes on, and it controls the closing line.

Meander corner

A corner set at the intersection of a survey line with the bank of a navigable water body or reservation boundary. Meander lines are for area computation, not boundary.

Proportionate measurement rule

When original corners are lost, re-establish the position by proportioning the record distance between the nearest existing original corners. Use only after exhausting evidence of the original corner.

Center quarter-section corner

Established at the intersection of lines connecting opposite quarter-section corners. It is common to four quarter sections and is not necessarily the midpoint of the section diagonals.

Fractional lot computation

Lots along navigable water or reservation boundaries are numbered and their areas computed from actual meander lines. Nominal 40-acre divisions do not apply to these fractional lots.

NAD83 and NATRF2022

NAD83 (2011) is the current horizontal datum for most Colorado work; NATRF2022 is its modern replacement. Coordinates must always state the datum and epoch used.

NAVD88 and NAPGD2022

NAVD88 is the vertical datum realized by tidal benchmarks; NAPGD2022 will replace it. Orthometric heights and datum tags must accompany all elevation work.

Combined factor

Combined factor equals grid scale factor times elevation factor. Grid distance equals ground distance times the combined factor; the inverse converts grid to ground.

Elevation factor

Approximated as R divided by R plus h, where R is mean Earth radius and h is ellipsoid height. It reduces ground distances to the ellipsoid before grid projection.

Geoid undulation relation

Orthometric height H equals ellipsoid height h minus geoid undulation N. GEOID18 and newer models supply N for converting GNSS ellipsoid heights to NAVD88 elevations.

Traverse relative precision

Linear misclosure divided by total traverse length, expressed as a ratio such as 1:10,000. Angular misclosure is compared with allowable error based on the number of angles.

Azimuth and bearing conversion

Azimuth is clockwise from north, 0 to 360 degrees. Bearings are measured from north or south toward east or west and must state the quadrant, e.g., N45E equals azimuth 45.

Coordinate area formula

Twice the area equals the sum over the traverse of Xi times Yi+1 minus Xi+1 times Yi, taken in order around the closed figure. The sign indicates traverse direction.

Horizontal curve tangent

Tangent T equals R times tangent of delta over two, where R is radius and delta is the central angle. Length L equals R times delta in radians.

Degree of curve definitions

Arc definition: D equals 5729.578 divided by R. Chord definition: D equals 2 arcsin of 50 divided by R. Colorado highway design typically uses the arc definition.

Vertical curve equation

Elevation y equals g1x plus r x squared over two, where r equals g2 minus g1 divided by L. The high or low point occurs where the slope equals zero.

Level loop misclosure

The difference between the starting and ending elevation after a closed loop. It is distributed in proportion to distance or number of setups, with signs opposite the misclosure.

Curvature and refraction correction

Combined correction approximately 0.0206 D squared, with D in hundreds of feet. It is applied to differential leveling sights and is negligible for short sights.

Construction control placement

Set horizontal and vertical control outside the limit of disturbance, and hold benchmarks stable. Verify design coordinates against control before staking any improvement.

Site calibration residuals

GNSS machine control requires a site calibration tying design coordinates to local control. Check residuals before production grading; large residuals indicate control or datum errors.

Subdivision plat requirements

Colorado subdivision plats follow municipal or county regulations and must be prepared by or under the supervision of a licensed land surveyor, with seal and signature.

As-built survey purpose

Compares constructed improvements with design, reports deviations, and verifies monumentation and easements are in place. Datum and coordinate basis must match the design documents.

Colorado survey licensure statute

Land surveyors are licensed under Title 12, Article 120, C.R.S., through the State Board of Licensure for Architects, Professional Engineers, and Professional Land Surveyors.

Responsible charge and sealing

A licensee may seal only work performed by them or under their direct supervision. Sealing work beyond one's competence or falsifying data are grounds for discipline.