Source:1 foot contours were generated for each production block from the final bare earth DEMs using ArcGIS software. Using ArcGIS software, the contours were validated for correct topology, including must not intersect, must not self intersect, and must not have dangles.  Contours are then manually reviewed with the 3D breaklines to ensure complete coverage, correct coding, data integrity and that contours behave correctly around water bodies, water crossings, and elevated features such as overpasses.  The contours are then clipped to individual tiles as creating one dataset for the entire project renders the feature class un-usable. Enclosed contours completely within building footprints were removed from the final contour dataset. Coordinate System:The data was developed based on a horizontal datum/projection of NAD83 (2011), State Plane Connecticut, U.S. Survey Feet and vertical datum of NAVD88 (GEOID18) Development:This vector tile package contains contour lines originally derived in the State Plane coordinate system. Prior to generating the tile service, individual contour blocks were merged into a single, seamless data layer to ensure consistency and completeness across the project area. This unified dataset served as the basis for creating the vector tile package. During the creation of the vector tile index, Web Mercator was used as the tiling reference to enable proper indexing and tile generation within ArcGIS Online. Please note that while the vector tile index references Web Mercator for mapping and display purposes, the contour line geometries are aligned with the original State Plane coordinate system, maintaining consistency with the source data used in production. This vector tile package contains contour lines originally derived in the State Plane coordinate system. Prior to generating the tile service, individual contour blocks were merged into a single, seamless data layer to ensure consistency and completeness across the project area. This unified dataset served as the basis for creating the vector tile package. During the creation of the vector tile index, Web Mercator was used as the tiling reference to enable proper indexing and tile generation within ArcGIS Online. Please note that while the vector tile index references Web Mercator for mapping and display purposes, but the contour lines were originally in the State Plane coordinate system Use Constraints:There are no formal use restrictions. However, users should be aware the conditions may have changed since the data was originally collected, and some areas may no longer accurately reflect current surface features. This data should not be used for critical decision-making without a full understanding of their limitations.