CT ECO Basic Data Guide

Natural Diversity Data Base Areas

Example of Natural Diversity Data Base Areas



Natural Diversity Data Base Areas represent known locations, both historic and extant, of state listed species. State listed species are those listed as Endangered, Threatened or Special Concern under the Connecticut Endangered Species Act (Connecticut General Statutes, Section 26-303). This dataset represents over 100 years worth of field observations, scientific collections, and publications. The data have been compiled from a variety of sources and in most cases do not represent a comprehensive or state-wide survey. Sources include state biologists, university students and professors, conservation organizations and private landowners.

Natural Diversity Data Base Areas are a generalized representation of species and community locations. The exact locations and species names have been masked to protect sensitive species from collection and disturbance. Natural Diversity Data Base Areas are represented as polygon areas and mapped for use at 1:24,000 scale (1 inch = 2,000 feet). This dataset is updated every six months and reflects information that has been submitted and accepted up to that point.


The Natural Diversity Data Base Areas were developed to help state agencies and citizens comply with the State Endangered Species Act. Under the Act, state agencies are required to ensure that any activity authorized, funded or performed by the state does not threaten the continued existence of endangered or threatened species. Applicants for certain state and local permits may be required to consult with the Department of Energy & Environmental Protection's Natural Diversity Data Base (NDDB) as part of the permit process.

Use Limitations

This information does not include Natural Area Preserves, designated wetland areas or wildlife concentration areas. Because of the limited attribute information and buffered locations, this dataset is not suitable for species distribution information or analysis. Use of this generalized product is limited to a pre-screening tool and follow up with the DEEP is required for more specific information. Some of the information used to define the Natural Diversity Data Base area boundaries is based on features appearing on or other information derived from 1:24,000-scale USGS topographic quadrangle maps. Consequently, use caution when displaying the Natural Diversity Data Base areas at map scales larger and more detailed than 1:24,000 scale (1 inch = 2,000 feet).

Dataset Information

  • Status - Updated every six months, generally in June and December.
  • Date of Data - Ongoing data collection.
  • Map Scale and Accuracy - 1:24,000 (1 inch = 2,000 feet)

Additional Documentation


GIS Data Download

  • Natural Diversity Database Areas is downloadable from DEEP GIS Data.
  • Connect GIS and AutoCAD software to this information online using the Habitat CT ECO Map Service.