Surveying Information and Unmanned Aerial System (a.k.a. Drone) Flights

Benchmarks & High Accuracy Reference Network Points

To assist surveyors working in Jefferson County, we have developed a map showing the Colorado High Accuracy Reference Network (CHARN) and the North American Vertical Datum 1988 (NAVD 88) benchmarks in the county. The Geodetic survey control was established by the National Geodetic Survey (NGS), Colorado Department of Transportation (CDOT), and Jefferson County.  To find survey point locations, use the county’s mapping service, jMap.  From the layers menu, mark the checkbox next to Survey Control Points. Under Survey Control Points, mark the checkbox next to CHARN. Selecting one of the survey control points will provide additional information including the Permanent Identifier (PID). The PIDs may be used to access data sheets from the National Geodetic Survey website

Land Surveys

Land surveys showing property boundaries must be filed with the Jefferson County Clerk and Recorder including land survey plats, improvement survey plats, ALTA surveys, and boundary surveys. Subdivision plats are different in that they divide land, typically through a city or county planning process, whereas land survey plats show the existing property boundary and often other land features.

Topographic Data

Recently updated topographic data, collected using LiDAR technology and covering Jefferson County is available on the Denver Regional Council of Governments (DRCOG) website. The area that covers the County is “Central A.” Users can search the DRCOG website by name or words such as LiDAR, DEM, contour, etc. 

Unmanned Aerial System Flights

Using Unmanned Aerial Systems (UAS), more commonly known as drones, is becoming an important tool on construction and engineering projects throughout the county.  They are helping to enhance traditional surveying by providing safe, cost-effective, high-resolution imagery for project design and inspection.