Connecticut Town Master Polygon includes the polygon features of a layer named Town Master. Town Master is a 1:24,000-scale, polygon and line feature-based layer that includes state, county and town (municipal) boundary features depicted on all of the U.S. Geological Survey (USGS) 7.5 minute topographic quadrangle maps that cover the State of Connecticut. This layer includes information for Connecticut and nearby portions of Massachusetts, New York and Rhode Island. Line features include State, county, and town (municipal) boundaries. Polygon features depict the geographic areas for individual towns (municipalities). A town may be represented by more than one polygon feature. For example, in addition to representing the portion of a town on the mainland, a polygon feature may also define an island along the coast of Long Island Sound. The layer is based on information from USGS topographic quadrangle maps published between 1969 and 1984 and latitude and longitude coordinates that define the boundary between the states of Connecticut and New York in Long Island Sound. Attribute information is comprised of codes to classify and cartographically symbolize political boundaries by type and identify the geographic areas encompassed by individual towns. Polygon feature attributes include state, county, and town codes and names. Feature length and geographic area are encoded for linear and polygon features, respectively. This layer was originally published in 1994. With the exception of the Middletown-Portand town boundary, the 2005 edition, includes the same features originally published in 1994. The Middletown-Portand was corrected and changed from its location, as depicted on the USGS topographic quadrangle maps, from along the banks of the Connecticut River in Portand to the middle of the Connecticut River south of Wilcox Island to the Pecausett Meadows area in Portland. Some attribute information has been slightly modified and made easier to use.

Connecticut Town Master is 1:24,000-scale base map data. It depicts the location of all state, county and town (municipal) boundaries published on the USGS topographic quadrangle maps. For base map purposes, use this layer with other 1:24,000-scale base map data such as Hydrography Master, Waterbody Master, Named Waterbody Master, Roads and Trails Master, Railroads Master, and Airports Master. All of these layers encompass the same geographic area, which includes Connecticut and nearby portions of Massachusetts, New York and Rhode Island. When only needing to display or print town boundaries for Connecticut, use either the Town Master layer and query for those features in Connecticut or use an alternate layer named Town, which only includes boundaries in Connecticut. Town Master may be used as a possible data source for other 1:24,000-scale layers having features that should coincide with the political boundaries on the USGS topographic quadrangle maps. Not intended for maps printed at map scales greater or more detailed than 1:24,000 scale (1 inch = 2,000 feet.)

Town Master only includes town boundaries. It does not include the boundary lines of individual boroughs such as the Borough of Stonington, for example. The boundaries of individual boroughs are included in the layer named Town Master from USGS, also published by the State of Connecticut, Department of Environmental Protection. In 2004, the State of Connecticut, Department of Environmental Protection developed automated procedures to maintaining feature topology and attribute integrity for the Town Master from USGS layer and layers derived from the Town Master from USGS layer such as the Town Master layer. Using ArcInfo Workstation 8.3 software and Arc Macro Language (AML) scripting environment, the automated procedures were recorded in an AML file named MAKECOVER.AML for the political boundary category of data published by the State of Connecticut, Department of Environmental Protection. The MAKECOVER.AML maintains the features and feature attribute data for the Town Master from USGS, Town Master, Town, Connecticut, and Connecticut Mainland layers. For additional information related to the original source of data from the U.S. Geological Survey, refer to the Data User Guides and Standards for 1:24,000-Scale Digital Line Graphs and Quadrangle Maps available from the U.S. Geological Survey, National Mapping Program.

Publication dates of the USGS 7.5 minute topographic quadrangle maps for the State of Connecticut through 1984.

None. The data is in the public domain and may be redistributed.

No restrictions or legal prerequisites for using the data. The data is suitable for use at appropriate scale, and is not intended for maps printed at scales greater or more detailed than 1:24,000 scale (1 inch = 2,000 feet). Although this data set has been used by the State of Connecticut, Department of Environmental Protection, no warranty, expressed or implied, is made by the State of Connecticut, Department of Environmental Protection as to the accuracy of the data and or related materials. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the State of Connecticut, Department of Environmental Protection in the use of these data or related materials. The user assumes the entire risk related to the use of these data. Once the data is distributed to the user, modifications made to the data by the user should be noted in the metadata. When printing this data on a map or using it in a software application, analysis, or report, please acknowledge the State of Connecticut, Department of Environmental Protection and the U.S. Geological Survey, National Mapping Program as the source for this information. For example, include the following data source description when printing this layer on a map: Political Boundaries - From the Town Master layer, compiled and published by CT DEP and USGS. Source map scale is 1:24,000.

Includes polygonal and linear features for political boundary information published on the U.S. Geological Survey 7.5 minute topographic quadrangle maps. Polygon and line features primarily represent town areas and boundaries, respectively, with attributes that distinguish state, county, and town (municipal) areas and boundaries. Information encoded about features includes Town Boundary polygon and arc (line) type classification, standard symbology classification schemes, state, town, county codes, feature area feature area in acreage and square miles, and feature length in miles. Use the AV_LEGEND attribute to symbolize features by type. Use the IMS_LEGEND attribute to more generally symbolize the features by type. To define a layer that only includes features in Connecticut, query line and polygon features for STATE_COD equal to "CT". To define a layer that includes political boundary line features typically displayed on a map, exclude unnecessary features by querying line features for AV_LEGEND not equal to "No Show" or IMS_LEGEND not equal to "No Show". Typically, line features with the "No Show" classification enclose polygon features that are not outlined on a map such as closure lines separating adjacent coastal water polygons or at the data limits.

Polygon features depict the geographic areas for individual towns (municipalities). A town may be represented by more than one polygon feature. For example, in addition to representing the portion of a town on the mainland, a polygon feature may define an island along the coast.

State of Connecticut, Department of Environmental Protection and U.S. Geological Survey, National Mapping Program

Polygon features conform to the following topological rules. Polygons are single part. There are no duplicate polygons. Polygons do not self overlap. Polygons do not overlap other polygons. Polygons are bound by lines. Line features conform to the following topological rules. Lines are single part. There are no duplicate lines. Lines do not self overlap. Lines do not overlap other lines. Lines intersect only at nodes, and nodes anchor the ends of all lines. Lines do not overshoot or undershoot other lines they are supposed to meet and intersect. The tests of logical consistency were performed by the State of Connecticut using ESRI ArcInfo software to maintain feature topology in ArcInfo coverage format. The data is topologically clean. The ArcInfo Clean function was repeatedly used following edits to verify topology and enforce a minimum distance between vertices of 4 feet (fuzzy tolerance) and a minimum allowed overshoot length of 10 feet (dangle length).

The completeness of the data reflects the USGS National Mapping Division standards for feature content of the data sources, which are the Large Scale (7.5 minute) Digital Line Graph (DLG) files available from the USGS. For Connecticut, the Large Scale DLG files used to create this layer are for the 1:24,000-scale topographic quadrangle maps published between 1969 and 1984.  The data is complete in the sense that it accurately reflects the contents of the most recently published USGS topographic quadrangle maps available at the time the State of Connecticut, Department of Environmental Protection began creating the layer. More recent quadrangle maps have been published by the USGS since 1984; however, the State of Connecticut did not incorporate this information into the layer. This data is not updated.

This data retains the political boundary (linear) feature types identified by the USGS and adds new polygon feature types of importance to the State of Connecticut for the purpose of mapping areas of the State of Connecticut and its counties and towns. All attributes have valid values. Values are within defined domains. The accuracy test for the TBARC_COD and TBPOLY_COD attribute values was conducted by comparing the political boundaries published on the source topographic quadrangle maps with 1:24,000-scale check plots or interactive displays of the data on a computer graphic system. These checkplots and computer displays depicted the features in different colors based on their respective TBARC_COD and TBPOLY_COD values for comparison with the paper quadrangle maps. The TOWN_ARC, TOWN_POLY, AV_LEGEND, and IMS_LEGEND attribute values are based on TBARC_COD and TBPOLY_COD values. TOWN_POLY is the English language equivalent of (decodes) the TBPOLY_COD field for polygon features. TOWN_ARC is the English language equivalent of (decodes) the TBARC_COD field for line features. AV_LEGEND and IMS_LEGEND are broad classifications of TBPOLY_COD and TBARC_COD values for polygon and line features, respectively. Based on the TBPOLY_COD and TBARC_COD attribute values, the TOWN_POLY, TOWN_ARC, AV_LEGEND, and IMS_LEGEND fields were populated through table joins to lookup tables. These decode values were not manually entered. The COASTA_COD line attributes for the shoreline features were transferred with the Coastal Arc (coastline) features copied from the Hydrography Master layer. All other polygon and line features were manually selected and assigned COASTP_COD and COASTA_COD values based on their relative landward and seaward orientation to Coastline Arcs. The COAST_POLY and COAST_ARC attributes decode the COASTP_COD and COASTA_COD attribute values and were populated through table joins to lookup tables. The COAST_POLY field decodes the COASTP_COD field for polygon features. The COAST_ARC field decodes the COASTA_COD field line features. The STATE_COD, FIPS, TOWN_NO, and CNTY_COD polygon attributes were manually entered and visually inspected and compared to information on the USGS 7.5 minute topographic quadrangle maps. The TOWN attribute is the English equivalent of (decodes) the TOWN_NO polygon attribute and was populated though a table join to a town lookup table. The STATE_FLG, FIPS_FLG, CONN_FLG, TOWN_FLG, CNTY_FLG, TNO_LEFT, and TNO_RIGHT line attributes were programmatically attributed, basing line attribute values on polygon and line feature topology relationships. The ACREAGE (area in acres) and AREA_SQMI (area in square miles) fields were automatically calculated for each polygon feature based on computer generated feature area in square feet. The LENGTH_MI (length in miles) field was automatically calculated for each line feature base on computer generated feature length.

This data complies with United States National Map Accuracy Standards for 1:24,000 scale maps. According to this standard, not more than 10 percent of the points tested are to be in error by more than 1/50 inch (40 feet) measured on the publication scale of a USGS 7.5 minute topographic quadrangle map.

Connecticut Town Master Polygon

Although this data set  has been used by the State of Connecticut, Department of Environmental Protection, no warranty, expressed or implied, is made by the State of Connecticut, Department of Environmental Protection as to the accuracy of the data and or related materials.  The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the State of Connecticut, Department of Environmental Protection in the use of these data or related materials. The user assumes the entire risk related to the use of these data. Once the data is distributed to the user, modifications made to the data by the user should be noted in the metadata.

Geographic information sytem (GIS), computer-aided drawing or other mapping software is necessary to display, view and access the information.

The data distributor does not provide custom GIS analysis or mapping services. Data is available in a standard format and may be converted to other formats, projections, coordinate systems, or selected for specific geographic regions by the party receiving the data.