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GIS or Unlicensed Surveying? The MySitePlan Case
For decades, a turf war has simmered between Geographical Information Systems (GIS) professionals and Licensed Land Surveyors. GIS firms argue they provide accessible data visualization. Surveyors argue that drawing boundaries without a license puts the public in danger. In 2023, the State of California drew a hard line in the sand with the MySitePlan action.
Case Summary: The California Board for Professional Engineers, Land Surveyors, and Geologists (BPELSG) issued a citation to a drafting company providing GIS-derived plot plans directly to homeowners, ruling the activity constituted the unlicensed practice of land surveying.
The Core Conflict: Drafting vs Surveying
In the digital age, companies like MySitePlan emerged to fill a market gap: A homeowner needs a simple map to get a permit for a shed or fence. Hiring a licensed surveyor costs $2,000 to $4,000 and takes two months. A drafting company offers to pull county GIS parcel data, overlay it on satellite imagery, draw the shed, and deliver a PDF in 24 hours for $150.
The problem? Establishing where a property line exists on the earth is the exclusive legal domain of a licensed surveyor.
The Board's Rulings
The California Board found that regardless of massive disclaimers stamped on the maps stating "This is not a boundary survey," the fundamental act of depicting the relationship between a proposed physical structure (the shed) and a legal boundary line (the property edge) constitutes land surveying.
- The Board noted that county GIS data is notoriously inaccurate, sometimes shifted by 10 to 30 feet.
- When a homeowner uses a GIS drafting product to build a structure 5 feet from a property line, relying on defective county GIS data practically guarantees the structure will violate zoning setbacks or encroach on the neighbor.
- The company was ordered to cease offering services in California that depict property lines relative to physical features without a licensed surveyor's stamp.
Broader Implications for the Geospatial Industry
The MySitePlan enforcement action sent shockwaves through the GIS freelance community. It established a chilling precedent for anyone drawing lines on a map for profit.
What GIS Professionals Can No Longer Do (in stringent states):
- Draft plot plans for building permits showing setbacks.
- Create boundary maps for property sales (even if heavily disclaimed).
- Overlay CAD drawings of new infrastructure onto tax parcels for final location approval.
What GIS Professionals CAN Do:
- Create thematic maps (e.g., population density).
- Map environmental features (wetlands, forestry) for planning, provided they are not tied definitively to property boundaries.
- Provide broad visualization and planning graphics, provided they are not submitted to regulatory bodies for dimensional approval.
Looking at shifted GIS data? See how combining UTM limits and Web Mercator distortion breaks maps.
—Try the Coordinate Mistake Simulator
E&O Insurance Reality: If a GIS firm is sued for an encroachment caused by their map, their Errors & Omissions insurance carrier will likely deny the claim. Standard GIS E&O policies exclude coverage for claims arising from activities that require a professional license (like surveying or engineering) if the insured does not hold that license.
FAQ
Is it illegal to draw my own plot plan?
As a homeowner, many municipalities allow you to draw your own plot plan for minor permits (like a deck) on your property. It only becomes "unlicensed practice" when someone offers that service to the public for a fee without a license.
Why is county GIS data inaccurate?
Counties digitized 100-year-old paper tax maps into computers without sending surveyors to measure the ground. The lines were "rubber-sheeted" to fit aerial imagery. They are for tax assessment, not boundary determination.
See also: GIS Legal Evidence | Standard of Care | Survey Dispute Cases
US State Plane (SPCS) Converters & Local Guides
Professional engineering and surveying transformations from state-specific conformal grids to GPS WGS84.
Professional Risk Notice
Using the wrong datum or applying coordinates without grid-to-ground correction can cause 1-400 metre positional errors —a leading cause of surveying negligence claims and contract disputes.
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Verified against professional geodetic standards
The $50,000 Geodetic Drift Liability: NAD83 vs WGS84
Because the North American Plate moves ~2cm/year, NAD83(2011) and WGS84(G1762) currently diverge by over 2.2 meters. Using a "standard" GPS WGS84 coordinate for a high-precision NAD83 cadastral staking has triggered $50,000 Professional Liability claims for foundational rework and utility misplacement.
Risk Exposure Metric:
2.2-Meter Tectonic Drift & Epoch Accumulation
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