Background

GIS Data for Orange County

The Orange County County GIS website for Landbase Information Systems offers an extensive, parcel-level digital basemap known as the OC Landbase, which contains over 687,000 subdivision parcels and includes legal parcels, districts, and transportation layers. Built on a robust foundation of the County Control Network with over 2,400 control points on a half-mile grid, the Landbase ensures high accuracy and seamless integration of new map information. Visitors can access the OC Landbase data via an Internet data portal where the content is downloadable in Shape File format, or request physical delivery on CD/DVD. The site provides detailed information on the coordinate system used (NAD 83, CA State Plane Zone VI, OCS 2017.5 adjustment) and emphasizes that the Landbase represents cadaster ownership lines based on recorded legal documents, distinct from assessor parcels. The site also encourages users to report errors or discrepancies to assist in data maintenance, and requires acknowledgment of Orange County as the source when using data for reports or publications. Additionally, FAQs and contact options are available to support users.