8.4 LIS/GIS Surveys, Classifications & the Board GIS Guidelines (21 NCAC 56 .1608)

8.4 LIS/GIS Surveys, Classifications & the Board GIS Guidelines (21 NCAC 56 .1608)

21 NCAC 56 .1608 is titled "Classification/Land Information System/Geographic Information System Surveys." Learn that title, because .1608 is the single most frequently misidentified rule number in North Carolina surveying prep material — it is routinely and wrongly described as an "incidental drainage" rule. It is not. Incidental drainage authority comes from G.S. 89C-3(7)a.3. and the exception in G.S. 89C-3(7)b.(vi), covered in Chapter 9. Rule .1608 is about geospatial data.

The topic also sits squarely inside the exam blueprint: the Board's published state-specific exam reference list expressly names the GIS Inclusions/Exclusions Guidelines among the Board Policies and Guidelines a candidate is expected to have read.

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1. The Statutory Hook — G.S. 89C-3(7)a.7.

The practice of land surveying expressly includes "Creating, preparing, or modifying electronic or computerized data, including land information systems and geographic information systems, relative to the performance of the practice of land surveying."

The qualifier "relative to the performance of the practice of land surveying" is doing real work. Building a parcel viewer is not automatically surveying; determining where a parcel line is and encoding that determination is.

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2. What an LIS/GIS Survey Is — .1608(a)

"Land Information System/Geographic Information System (LIS/GIS) surveys are defined as the measurement of existing surface and subsurface features for the purpose of determining their accurate geospatial location for inclusion in an LIS/GIS database."

The rule then draws the licensure line:

"All LIS/GIS surveys as they relate to property lines, rights-of-way, easements, subdivisions of land, the position for any survey monument or reference point, the determination of the configuration or contour of the earth's surface or the position of fixed objects thereon, and geodetic surveying ... shall be performed by a Land Surveyor who is a licensee of this Board unless exempt by G.S. 89C-25."

Two exam-relevant consequences follow. First, subsurface utility location for a GIS database is inside the rule — it says "surface and subsurface features." Second, the escape valve is the general exemption statute, G.S. 89C-25, whose most relevant subdivisions here are (4) work as an employee or assistant under the responsible charge of a licensee and (6) government employees practicing solely for the government on government-owned works and projects.

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3. The Accuracy Classes — .1608(a)(1) and (a)(2)

Five general classifications are established, "any of which may be specified by the client. In the absence of a specified standard, the surveyor shall conform the survey to the requirements for a Class B survey."

Horizontal — relative accuracy

These are the same five values .1606 uses for topographic and planimetric mapping, which is a useful memory hook: 0.10 / 1.64 / 3.28 / 6.56 / 16.40 feet covers both rules.

Vertical — three classifications

.1608(b) then preserves everything else: "Nothing in this Rule negates or replaces the relative accuracy standards found in Rules .1601 through .1607 of this Section." A GIS-driven project that also retraces a boundary is still a boundary survey governed by .1602, .1603, and .1604.

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4. The LIS/GIS Certificate — .1608(c) and (d)

The PLS in responsible charge of the LIS/GIS boundary or geodetic control survey shall certify, in written or digital form, all of the following:

1. Class of LIS/GIS survey, and the method of measurement used to evaluate the accuracy, described as statistical testing or least squares adjustment results, comparison with values of higher accuracy, and repeat measurements. The rule then defines the reporting standard: "the reporting standard in the horizontal component is the radius of a circle of uncertainty, such that the true or theoretical location of the point falls within that circle 95 percent of the time."
2. Method of measurement — i.e., global navigation satellite systems, electronic scanners, theodolite and electronic distance meter, transit and tape.
3. Date(s) of the survey.
4. Datum used for the survey.

"I, ______________________, certify that this project was completed under my
direct and responsible charge from an actual survey made under my supervision;
that this survey was performed to meet the requirements for an LIS/GIS survey
[21 NCAC 56.1608] to the accuracy of Class ____ and vertical accuracy; when
applicable to the Class ___ standard method used to evaluate the accuracy was
_______________; method of measurement ______________; date(s) of survey
___________; datum used for survey __________; and all coordinates are based on
______________ ['NAD 83' and realization (date of adjustment of coordinate
system) or 'NAD 27'] and all elevations are based on ________________
(NGVD 29, NAVD 88, or other)."

Note the difference in how horizontal uncertainty is reported across the three rules a modern surveyor touches: .1603 offers a ratio of precision or an error-ellipse semi-axis at 95 percent; .1606 points to FGDC Part 1 reporting; .1608 uses a radius of a circle of uncertainty at 95 percent. They are not interchangeable phrasings, and a certificate should use the language of the rule it invokes.

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5. The Board's GIS Inclusions/Exclusions Guidelines

The Board publishes a short policy distinguishing GIS activity that constitutes the practice of land surveying from activity that does not. The organizing question is not the software; it is whether the work determines or represents the location of a boundary, monument, or feature as a matter of position, and whether the public will rely on it as such.

+-----------------------------------------------------------------------------+
|          THE ORGANIZING QUESTION FOR GIS WORK IN NORTH CAROLINA             |
|                                                                             |
|   Does the activity DETERMINE or REPRESENT the geospatial position of a     |
|   boundary, right-of-way, easement, monument, or physical feature in a way   |
|   the public or a client will rely on as a positional statement?            |
|                                                                             |
|      YES  -->  the practice of land surveying; a Board licensee must be in  |
|                responsible charge, unless exempt by G.S. 89C-25             |
|                                                                             |
|      NO   -->  cartographic display, thematic mapping, database             |
|                administration, analysis of data positioned by others        |
+-----------------------------------------------------------------------------+

Typical inclusions — work requiring a licensee:

• Field measurement of features (surface or subsurface) to establish their coordinates for a GIS layer.
• Determining or depicting the position of property lines, rights-of-way, easements, or subdivision boundaries.
• Setting, resetting, or determining the position of any survey monument or reference point.
• Determining the configuration or contour of the earth's surface, or the position of fixed objects on it.
• Geodetic control work supporting a GIS.

Typical exclusions — work not requiring a licensee:

• Compiling, converting, or displaying data whose positions were established by others, where no new positional determination is made.
• Thematic and analytical mapping — zoning, demographics, land use, environmental overlays — that does not purport to locate boundaries.
• Database design, administration, and maintenance.
• Tax parcel mapping maintained for ad valorem assessment, which by long-settled practice is not a boundary determination.

[!CAUTION] The exclusion for parcel-base GIS is an exclusion from licensure, not a license to mislead. A parcel layer distributed without a disclaimer invites reliance it cannot support. The professional answer is the one .1604(b) and G.S. 47-30(d) already model for plats: say what the lines are, and say where they came from. A surveyor who exports a boundary from a tax parcel layer into a survey product without independent record research has violated 21 NCAC 56 .1602(c) regardless of what the GIS metadata says.