Checked
State dataMaps & Geospatial
RiverCOG
Published by State of Connecticut · Updated 11/18/2025
- Last updated
- 11/18/2025
- First published 10/27/2025
- Update frequency
- Not listed
- Formats
- 7
- CSV, XLS, TXT
- Coverage
- Connecticut
- Statewide
About this dataset
Contours are lines of equal elevation. This is a contour feature layer for the state of Connecticut derived from the index contour in the 1' contour data set. All closed polygons less than 35' length have been deleted to improve loading performance. This data set is derived from the 2023 Lidar with15 to 20 points per meter squared.
Source:
1 foot contours were generated for each production block from the final bare earth DEMs using ArcGIS software. Contours are labeled as intermediate or index with index contours set to every 10th interval. 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)
Contours were cut by Town then merged into COGs
Geographic Extent
- Coverage: State of Connecticut
Classifications
- Sensitivity: Public
- Usage: Public Use
- Quality: High Quality
- Known Quality Issues: None known, but subject to standard limitations of third-party commercial data
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Files and access
Links open the official government source
- CSVgeodata.ct.govCSV
- Excelgeodata.ct.govXLS
- ArcGIS GeoServiceservices3.arcgis.comJSON
- GeoJSONgeodata.ct.govGeoJSON
- File Geodatabasegeodata.ct.govZIP
- Shapefilegeodata.ct.govZIP
- KMLgeodata.ct.govKML
- Feature Collectiongeodata.ct.govTXT
- GeoPackagegeodata.ct.gov
- SQLite Geodatabasegeodata.ct.gov
- ArcGIS Hub Datasetgeodata.ct.govWeb page
Links open outside websites we do not control.
Frequently asked questions
- Who publishes RiverCOG?
- State of Connecticut publishes this dataset on Data.gov.
- How often is it updated?
- The publisher does not list a schedule. The last update was on 11/18/2025.
- How do I download it?
- It is available as CSV, XLS, JSON, GeoJSON, ZIP, KML, TXT. Use the links in Files and access, which open the official government source.
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Where this catalog comes from
- Data.gov CatalogU.S. General Services Administration
- State and local open data portalsSocrata Discovery API
- State and city CKAN portalsCalifornia, Virginia, Boston, Houston and more
- Government ArcGIS Hub sitesCity and county GIS data
Catalog checked 10/24/2026
We list dataset descriptions only. Downloads and APIs link straight to the official government source, which holds the current version and its terms of use.
Source: Data.gov · Last updated 10/24/2026 · Listing only; the data stays with the publisher
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