Parcels, or defined pieces of land, delineate how land is divided. Parcels are the key mapping unit for town operations including assessment, public safety, permitting and more.
Connecticut does not have a statewide parcel dataset. Parcels are maintained at the local level (town or city) in different ways. Some municipalities have GIS staff who maintain parcels. Some Councils of Governments (COGs) maintain parcels for their member towns and some towns hire consultants. Every town in Connecticut has digital parcels. Most have an online viewer so that citizens can view and explore the map layers.
Previously, the only other "statewide" parcel service was created through the Department of Energy and Environmental Protection's (DEEP) Protected Open Space Mapping (POSM) project. Parcels were necessary in order to catalog and map Open Space. The POSM parcel layer is described in the CT ECO Resource Guide which explains how it is a combination of parcels collected from municipalities with creation dates ranging from 2003 to 2010. This layer is not updated and not all towns contributed.
In 2018, Public Act 18-175, section 6 was passed and requires each municipality to submit a digital parcel file and some assessment information each year to the Council of Governments (COGs) to which it belongs. The Office of Policy and Management (OPM) subsequently asks the COGs to voluntarily share the files so they can be made available for download in one location on the OPM website.
CT ECO is publishing the parcel information downloaded directly from OPM because of it's high value for many applications across the state. Without the service and viewer, the parcel layers are only available in individual town viewers or for download in GIS format. GIS files require software and know-how to view and use. CT ECO is simply sharing the information and has no involvement in the creation or editing of the datasets including tabular information.