GIS Status

Geodetic Control Network: Products are complete for the entire County. Network of GPS controlled permanent monument markers with respective azimuth (backsight) marker and additional County boundary monuments for the border with Goochland County. These monuments meet or exceed the National Geodetic Survey standards for First Order, First Class monuments. The monuments exceed the 1:440,000 accuracy level.

Digital Orthophotographic Products: Complete for the entire County, Aerial photography Date of February, 1998, March 2003 and February 2008. These products are 6-inch ground resolution digital orthocorrected images in 24 bit (true) color. The images have also been resampled to provide an additional product at the resolution of 4 feet on the ground. High Resolution Digital Orthophotographic products meet or exceed the American Society of Photogrametry and Remote Sensing (ASPRS) accuracy standards for maps at the scale of 1:1,200, or 1 inch to 100 feet. The accuracy standard is as follows:

Horizontal: 95% of measurable features are within 3.33 feet of their actual location on the surface of the County.

Digital Planimetric and Topographic Base Map: Complete for the entire County. Photogrametrically compiled features based on aerial photography of February, 1998, and updated with the aerial photography of March, 2003 and again in February 2008. Photogrametric update of planimetric base map features scheduled to be completed during next aerial photography scheduled for Winter of 2007. All Photogrametrically compiled planimetric base map features meet or exceed the American Society of Photogrametry and Remote Sensing (ASPRS) accuracy standards for maps at the scale of 1:1,200, or 1 inch to 100 feet. The accuracy standards are as follows:

Horizontal: 95% of measurable features are within 3.33 feet of their actual location on the surface of the County. Vertical: 95% of contour features are within 1/2 of the contour interval (1 foot).

Planimetric layers include:

Road centerlines, edge of roadway, parking lots, driveways, building outlines, barriers, streams and water bodies (hydrography), tree cover, and railroads.

Topographic layers include: 2 foot interval contour lines, Digital Terrain Model (DTM), and Spot elevations.

Digital Cadastral Map: Available for the entire County developed through digital conversion, vectorization, and best-fit to planimetric features; delineation of Real Estate Property boundaries, including Right-of-Ways, and major Easements. This product was initially prepared for completeness through January 1, 2000. Parcel subdivisions and splits are updated on an ongoing basis as Real Estate transactions are recorded.

The Cadastral layers also include: Zoning, 2010 and 2026 Land Use Plan, and Public Safety Response and Reporting Zones.

Digital Utilities Map: Developed through digital conversion of the County's water and sewer map books and GPS acquisition of manholes, valves, and meters, including utilities Right-of-Ways and Easements. This product is complete Countywide and is currently under maintenance and update as new utility feature as-built plans are submitted.

The GIS products can be obtained in any of the following formats: Printed maps, AutoCAD DXF files, complete with Z values for elevation data, ArcView Shape Files, and ESRI Geodatabases.