Connecticut Towns for Identify is a 1:24,000-scale polygon feature-based layer with a single polygon feature for each Connecticut town. Polygon features depict the geographic areas for individual towns (municipalities). The layer is based in part on information from USGS topographic quadrangle maps published between 1969 and 1984 and does not reflect official town boundary information. In this layer, a town area is represented as a single polygon feature and includes all of the land and water area encompassed by the town, as generally depicted on a USGS 7.5 minute topographic quadrangle map. Note, polygon features for towns along the coast artificially extend to the CT-NY state boundary in Long Island Sound. Feature attribute information denotes the town and county number and name for each feature. This layer was originally published in 1994. With the exception of the Middletown-Portand town boundary, the 2008 edition includes the same features originally published in 1994. The Middletown-Portand town boundary 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.
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.
Polygon features depict the geographic areas for individual towns (municipalities). A town is represented by one polygon feature that includes all of the land and water area encompassed by the town. Polygon features for towns along the coast artificially extend to the CT-NY state boundary in Long Island Sound. (Source: State of Connecticut, Department of Environmental Protection and U.S. Geological Survey, National Mapping Program)
Internal feature number. (Source: ESRI)
Feature geometry. (Source: ESRI)
State Code - 2 Digit FIPS State Code that identifies the State in which the feature is located. Based on U.S. Department of Commerce, 1987, Codes for the Identification of the States, the District of Columbia and the Outlying Areas of The United States, and Associated Areas (Federal Information Processing Standard 5-2): Washington, DC, National Institute of Standards and Technology. (Source: U.S. Department of Commerce, Bureau of the Census)
| Value | Definition |
|---|---|
| CT | Connecticut |
FIPS State County Code - The 5-digit FIPS county designation for features in Connecticut, Massachussets, New York, and Rhode Island from U.S. Department of Commerce, Bureau of the Census, Geography Division, 1990, Counties and Equivalent Entities of the United States, Its Possessions, and Associated Areas (Federal Information Processing Standard 6-4): Washington, DC, National Institute of Standards and Technology. FIPS PUB 6-4 is available online at http://www.itl.nist.gov/fipspubs/fip6-4.htm (Source: U.S. Department of Commerce, Bureau of the Census)
Town Number - ID number for the Connecticut Town (municipality), based on the Town Codes issued by the State of Connecticut, Office of the State Controller, which range from 1 to 169. (Source: State of Connecticut, Department of Environmental Protection and State of Connecticut, Office of the State Controller)
| Value | Definition |
|---|---|
| 0 | Not a Connecticut Town |
| 1 | Andover |
| 2 | Ansonia |
| 3 | Ashford |
| 4 | Avon |
| 5 | Barkhamsted |
| 6 | Beacon Falls |
| 7 | Berlin |
| 8 | Bethany |
| 9 | Bethel |
| 10 | Bethlehem |
| 11 | Bloomfield |
| 12 | Bolton |
| 13 | Bozrah |
| 14 | Branford |
| 15 | Bridgeport |
| 16 | Bridgewater |
| 17 | Bristol |
| 18 | Brookfield |
| 19 | Brooklyn |
| 20 | Burlington |
| 21 | Canaan |
| 22 | Canterbury |
| 23 | Canton |
| 24 | Chaplin |
| 25 | Cheshire |
| 26 | Chester |
| 27 | Clinton |
| 28 | Colchester |
| 29 | Colebrook |
| 30 | Columbia |
| 31 | Cornwall |
| 32 | Coventry |
| 33 | Cromwell |
| 34 | Danbury |
| 35 | Darien |
| 36 | Deep River |
| 37 | Derby |
| 38 | Durham |
| 39 | Eastford |
| 40 | East Granby |
| 41 | East Haddam |
| 42 | East Hampton |
| 43 | East Hartford |
| 44 | East Haven |
| 45 | East Lyme |
| 46 | Easton |
| 47 | East Windsor |
| 48 | Ellington |
| 49 | Enfield |
| 50 | Essex |
| 51 | Fairfield |
| 52 | Farmington |
| 53 | Franklin |
| 54 | Glastonbury |
| 55 | Goshen |
| 56 | Granby |
| 57 | Greenwich |
| 58 | Griswold |
| 59 | Groton |
| 60 | Guilford |
| 61 | Haddam |
| 62 | Hamden |
| 63 | Hampton |
| 64 | Hartford |
| 65 | Hartland |
| 66 | Harwinton |
| 67 | Hebron |
| 68 | Kent |
| 69 | Killingly |
| 70 | Killingworth |
| 71 | Lebanon |
| 72 | Ledyard |
| 73 | Lisbon |
| 74 | Litchfield |
| 75 | Lyme |
| 76 | Madison |
| 77 | Manchester |
| 78 | Mansfield |
| 79 | Marlborough |
| 80 | Meriden |
| 81 | Middlebury |
| 82 | Middlefield |
| 83 | Middletown |
| 84 | Milford |
| 85 | Monroe |
| 86 | Montville |
| 87 | Morris |
| 88 | Naugatuck |
| 89 | New Britain |
| 90 | New Canaan |
| 91 | New Fairfield |
| 92 | New Hartford |
| 93 | New Haven |
| 94 | Newington |
| 95 | New London |
| 96 | New Milford |
| 97 | Newtown |
| 98 | Norfolk |
| 99 | North Branford |
| 100 | North Canaan |
| 101 | North Haven |
| 102 | North Stonington |
| 103 | Norwalk |
| 104 | Norwich |
| 105 | Old Lyme |
| 106 | Old Saybrook |
| 107 | Orange |
| 108 | Oxford |
| 109 | Plainfield |
| 110 | Plainville |
| 111 | Plymouth |
| 112 | Pomfret |
| 113 | Portland |
| 114 | Preston |
| 115 | Prospect |
| 116 | Putnam |
| 117 | Redding |
| 118 | Ridgefield |
| 119 | Rocky Hill |
| 120 | Roxbury |
| 121 | Salem |
| 122 | Salisbury |
| 123 | Scotland |
| 124 | Seymour |
| 125 | Sharon |
| 126 | Shelton |
| 127 | Sherman |
| 128 | Simsbury |
| 129 | Somers |
| 130 | Southbury |
| 131 | Southington |
| 132 | South Windsor |
| 133 | Sprague |
| 134 | Stafford |
| 135 | Stamford |
| 136 | Sterling |
| 137 | Stonington |
| 138 | Stratford |
| 139 | Suffield |
| 140 | Thomaston |
| 141 | Thompson |
| 142 | Tolland |
| 143 | Torrington |
| 144 | Trumbull |
| 145 | Union |
| 146 | Vernon |
| 147 | Voluntown |
| 148 | Wallingford |
| 149 | Warren |
| 150 | Washington |
| 151 | Waterbury |
| 152 | Waterford |
| 153 | Watertown |
| 154 | Westbrook |
| 155 | West Hartford |
| 156 | West Haven |
| 157 | Weston |
| 158 | Westport |
| 159 | Wethersfield |
| 160 | Willington |
| 161 | Wilton |
| 162 | Winchester |
| 163 | Windham |
| 164 | Windsor |
| 165 | Windsor Locks |
| 166 | Wolcott |
| 167 | Woodbridge |
| 168 | Woodbury |
| 169 | Woodstock |
Town Name - Text values that correspond to numeric TOWN_NO attribute values. TOWN is the English language equivalent of (decodes) the TOWN_NO field. (Source: State of Connecticut, Department of Environmental Protection and State of Connecticut, Office of the State Controller)
County Code - Numeric Code for the County established by Office of Policy and Management. These codes are listed at http://www.opm.state.ct.us/pdpd3/data/twn.htm (Source: State of Connecticut, Office of Policy and Management)
| Value | Definition |
|---|---|
| 0 | Not a Connecticut County |
| 1 | Fairfield |
| 3 | Hartford |
| 5 | Litchfield |
| 7 | Middlesex |
| 9 | New Haven |
| 11 | New London |
| 13 | Tolland |
| 15 | Windham |
County - Text values that correspond to numeric CNTY_COD attribute values. COUNTY is the English language equivalent of (decodes) the CNTY_COD field. (Source: U.S. Department of Commerce, Bureau of the Census)
Includes one polygon feature for each Connecticut town (municipality). For inland towns, town polygon features are based on political boundary information published on the U.S. Geological Survey 7.5 minute topographic quadrangle maps. For towns along the Connecticut coastline, town polygon features also encompass the waters of Long Island Sound and are based on the political boundary information published on the U.S. Geological Survey 7.5 minute topographic quadrangle maps that has been extended (by CT DEP) to the CT-NY state boundary in Long Island Sound. Note, the USGS 7.5 minute topographic quadrangle maps do not include complete and consistent political boundary information in Long Island Sound between towns along the coast. On these maps, town boundaries do not extend or only partially extend into Long Island Sound. Consequently, to enclose all town polygons in Long Island Sound, the land and near-shore boundaries in Long Island Sound for the following shoreline towns were artificially extended in a southerly direction from their end point shown on the USGS topographic quadrangle map to the CT-NY boundary in the middle of Long Island Sound - Greenwich, Stamford, Darien, Norwalk, Westport, Fairfield, Bridgeport, Stratford, Milford, West Haven, New Haven, East Haven, Branford, Guilford, Madison, Clinton, Westbrook, Old Saybrook, Old Lyme, East Lyme, and Waterford. Areas in Long Island Sound for these towns are not based on official town boundaries. Use these town polygon features to identify the town a point on the land is located in. Also use this layer to identify the town a point located in the waters of Long Island Sound should be associated with (and presumed to be located in), based on proximity to the nearest coastal town. Label polygon feature with the TOWN attribute to display town names.
Connecticut Town numbers, based on the Town Codes issued by the State of Connecticut, range from 1 to 169 in the following order: Andover (1), Ansonia (2), Ashford (3), Avon (4), Barkhamsted (5), Beacon Falls (6), Berlin (7), Bethany (8), Bethel (9), Bethlehem (10), Bloomfield (11), Bolton (12), Bozrah (13), Branford (14), Bridgeport (15), Bridgewater (16), Bristol (17), Brookfield (18), Brooklyn (19), Burlington (20), Canaan (21), Canterbury (22), Canton (23), Chaplin (24), Cheshire (25), Chester (26), Clinton (27), Colchester (28), Colebrook (29), Columbia (30), Cornwall (31), Coventry (32), Cromwell (33), Danbury (34), Darien (35), Deep River (36), Derby (37), Durham (38), Eastford (39), East Granby (40), East Haddam (41), East Hampton (42), East Hartford (43), East Haven (44), East Lyme (45), Easton (46), East Windsor (47), Ellington (48), Enfield (49), Essex (50), Fairfield (51), Farmington (52), Franklin (53), Glastonbury (54), Goshen (55), Granby (56), Greenwich (57), Griswold (58), Groton (59), Guilford (60), Haddam (61), Hamden (62), Hampton (63), Hartford (64), Hartland (65), Harwinton (66), Hebron (67), Kent (68), Killingly (69), Killingworth (70), Lebanon (71), Ledyard (72), Lisbon (73), Litchfield (74), Lyme (75), Madison (76), Manchester (77), Mansfield (78), Marlborough (79), Meriden (80), Middlebury (81), Middlefield (82), Middletown (83), Milford (84), Monroe (85), Montville (86), Morris (87), Naugatuck (88), New Britain (89), New Canaan (90), New Fairfield (91), New Hartford (92), New Haven (93), Newington (94), New London (95), New Milford (96), Newtown (97), Norfolk (98), North Branford (99), North Canaan (100), North Haven (101), North Stonington (102), Norwalk (103), Norwich (104), Old Lyme (105), Old Saybrook (106), Orange (107), Oxford (108), Plainfield (109), Plainville (110), Plymouth (111), Pomfret (112), Portland (113), Preston (114), Prospect (115), Putnam (116), Redding (117), Ridgefield (118), Rocky Hill (119), Roxbury (120), Salem (121), Salisbury (122), Scotland (123), Seymour (124), Sharon (125), Shelton (126), Sherman (127), Simsbury (128), Somers (129), Southbury (130), Southington (131), South Windsor (132), Sprague (133), Stafford (134), Stamford (135), Sterling (136), Stonington (137), Stratford (138), Suffield (139), Thomaston (140), Thompson (141), Tolland (142), Torrington (143), Trumbull (144), Union (145), Vernon (146), Voluntown (147), Wallingford (148), Warren (149), Washington (150), Waterbury (151), Waterford (152), Watertown (153), Westbrook (154), West Hartford (155), West Haven (156), Weston (157), Westport (158), Wethersfield (159), Willington (160), Wilton (161), Winchester (162), Windham (163), Windsor (164), Windsor Locks (165), Wolcott (166), Woodbridge (167), Woodbury (168), and Woodstock (169).
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.
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Connecticut Towns for Identify only should be used to determine (identify) the Connecticut town that a point feature or XY coordinate is located in. It should not be displayed on a map or used for cartographic purposes due to the unusual nature of town boundaries in Long Island Sound. Use these town polygon features to identify the town a point on the land is located in. Also use this layer to identify the town a point located in the waters of Long Island Sound should be associated with (and presumed to be located in), based on proximity to the nearest coastal town. Note that town polygon features of this layer are based on a combination of political boundary information depicted on the U.S. Geological Survey 7.5 minute topographic quadrangle maps and interpolated information. For inland towns, town polygon features are entirely based on political boundary information published on the U.S. Geological Survey 7.5 minute topographic quadrangle maps. For towns along the Connecticut coastline, town polygon features also encompass the waters of Long Island Sound and are based on political boundary information published on the U.S. Geological Survey 7.5 minute topographic quadrangle maps that has been extended and enterpolated by CT DEP to the CT-NY state boundary in Long Island Sound. Label polygon feature with the TOWN attribute to display town names.
USGS Large Scale Digital Line Graph (DLG) data are digital representations of the cartographic (base map) information published on the 1:24,000-scale, 7.5 minute topographic quadrangle maps. The USGS produces DLG data per 7.5 minute quadrangle. DLG data is organized into categories such as hydrography, boundaries, and transportation. At the time the State of Connecticut began developing the Town Master from USGS layer in the late 1980's, Large Scale DLG files were available for 112 of the 115 topographic quadrangle maps necessary to cover Connecticut. Large Scale DLG files were not available for the West Springfield Mass-Conn, Springfield South Mass-Conn, and Hamden Mass-Conn quadrangle. It is important to note that the Large-Scale DLGs were produced in the 1980's at a time when the USGS was developing standards, conventions, and procedures to convert topographic quadrangle maps into digital spatial data. The Connecticut DLG files were produced by digitizing from stable-base Mylars using a digitizing tablet to capture the digital data. The features were manually digitized and attributed. Today, there are other methods available for producing DLGs. For additional DLG documentation, 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.
In the absence of Large Scale DLG data, the USGS provided the State of Connecticut with raster image scans of the Mylar separates used to publish the black, red, brown, and blue inks for 3 of the 115 topographic quadrangle maps that cover Connecticut. These quadrangles include West Springfield Mass-Conn, Springfield South Mass-Conn, and Hamden Mass-Conn.
Town Master features for each quadrangle map. Each quadrangle Town Master layer is in ArcInfo Coverage format.
Hydrography Master is a 1:24,000-scale, polygon and line feature-based layer that includes all hydrography features depicted on all of the U.S. Geological Survey (USGS) 7.5 minute topographic quadrangle maps that cover the State of Connecticut. This data source refers to all Hydrography features combined in one statewide layer. Hydrography Master is in ArcInfo Coverage format.
The boundary line between the states of Connecticut and New York is described in Special Laws of Connecticut, Volume 16, pages 1104-1108, Senate Bill #322, An Act Establishing The Boundary Line Between Connecticut and New York. This Special Act documents the latitude and longitude coordinates of the state boundary monuments on the ground and points in the waters of Long Island Sound. These geodetic positions are based on Clark's spheroid of 1866 and are in degrees, minutes and seconds (DMS). The following boundary points enumerated in this act were used to define the state boundary in Long Island Sound. Point No. 170: Latitude 40 57 03.228, Longitude -73 36 46.418 Point No. 171: Latitude 41 15 31.321, Longitude -72 05 24.685 Point No. 172: Latitude 41 17 26.341, Longitude -72 01 10.937 Point No. 173: Latitude 41 18 37.835, Longitude -71 55 47.626 Point No. 174: Latitude 41 18 16.249, Longitude -71 54 28.477
This data source refers to all political boundary features combined in one statewide layer. Since initial publication in 1994, subsequent editions of this master layer were generated by the State of Connecticut in order to change data format, convert from NAD 27 to NAD 83, and improve the quality and accuracy of both feature geometry and feature attribute information. Consequently, over a period of many years, different versions of the layer were produced. Various editions of Town Master from USGS are reflected by those process steps in which the Town Master from USGS layer is identified as both the Source Used and the Source Produced. Town Master from USGS is in ArcInfo Coverage format.
A polygon feature-based layer representing all areas enclosed by all political boundary features depicted on all of the U.S. Geological Survey (USGS) 7.5 minute topographic quadrangle maps that cover the State of Connecticut. Town_Master_USGS_Poly.shp is in Shapefile format.
A polygon feature-based layer representing all areas enclosed by all political boundary features depicted on all of the U.S. Geological Survey (USGS) 7.5 minute topographic quadrangle maps that cover the State of Connecticut. Town_Master_USGS_Poly is in Geodatabase Feature Class format.
Town_Identify is in GeoDatabase Feature Class format
DLG to ArcInfo coverage format conversion - Using ESRI ArcInfo software, the State of Connecticut, Department of Enviromental Protection converted the (political) boundaries category for each Large Scale DLG file to ArcInfo Coverage format, resulting in one ArcInfo Coverage of polygon and line features for 112 of the 115 quadrangle areas that cover Connecticut. Each Coverage was converted from UTM to Connecticut State Plane, North American Datum of 1927 (NAD27).
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Image to vector (ArcInfo coverage) format conversion - Using ESRI ArcInfo software, the black ink image files that depict the political boundary and other topo map features printed in black on 3 of 115 topographic quadrangle maps were georeferenced to Connecticut State Plane, North American Datum of 1927 (NAD27) by registering the image corners to the corresponding quadrangle corner tics. In an interactive ArcInfo editing environment, the geogreferenced image was displayed in the background in order to visually identify political boundaries that needed to be vectorized (digitized). Features that would have been included in the DLG Political Boundary category by the USGS were were manually digitized on the screen (heads-up digitizing) at display scales greater than 1:24,000. Polygon and line features were assigned TBPOLY_COD and TBARC_COD values based on their cartographic representation on the topographic quadrangle maps. Check plots were produced to inspect digitizing quality and the assignment of TBPOLY_COD and TBARC_COD values.
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Attribute value verification - The quality and accuracy of the digitizing and coding for all features was checked by comparing the features in each ArcInfo Coverage with the state, county, town and borough boundary lines published on the published USGS topographic quadrangle maps. Visual comparisons using 1:24,000-scale paper check plots combined with automated procedures to identify inconsistent attribute coding were the primary means of evaluating and correcting obvious errors with the original DLG data. Where necessary, corrections were made to DLG major and minor codes in the ArcInfo Coverages. The original DLG major and minor codes were replaced by TBPOLY_COD and TBARC_COD attribute in the final Town Master from USGS layer.
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Quadrangle coverage edgematch - Using ESRI ArcInfo software, the individual 7.5 minute quadrangle coverages of Town Master features were systematically edgematched. Line features that cross adjacent quadrangles were moved to make their end-point coordinates identical along quadrangle boundaries through a process of checkerboard style edgematching. Features along the edges of every other quadrangle were adjusted. The ends of poltical boundary lines were snapped to align with the connecting stationary features on adjacent quadrangles if their end-points were generally within 20 feet. Ends of line features were adjusted to match the location of the ends of the corresponding feature on adjacent quadrangles so that features would connect when the quadrangle coverages were appended in the subsequent process step.
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Statewide layer creation - Using ESRI ArcInfo sofware, all (115) 7.5-minute quadrangle coverages were appended to form a single, statewide layer named Town Master from USGS. Linear features were unsplit (merged) to eliminate unnecessary pseudo nodes between similar features from adjacent quadrangle areas. Polygon features were merged across quadrangle boundaries. Polygon features were then manually attributed with the appropriate STATE_COD, FIPS_COD, TOWN_NO, CONN_CITY, and CONN_BORO attribute values. 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. Line features were largely encoded using feature topology-based table joins for assigning values to the STATE_FLG, FIPS_FLG, CONN_FLG, TOWN_FLG, CITY_FLG, BORO_FLG, CNTY_FLG, TNO_LEFT, TOWN_LEFT, TNO_RIGHT, TOWN_RIGHT, CITY_LEFT, and CITY_RIGHT attributes. Additionally, coastline and island feature information from the Hydrography Master layer was incorporated into this layer in order to enclose the land areas encompassed by towns adjacent to Long Island Sound and to define the island polygon features that are part of the land area for coastal towns. Features derived from the Hydrography Master layer are attributed with specific COASTA_COD and COASTP_COD values. The COASTA_COD line attributes for the shoreline features were transferred with the Coastal Arc (coastline) features copied from the Hydrography 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. With the state boundary in Long Island Sound incomplete because most of it is not depicted on USGS topographic quadrangle maps, a boundary line feature representing the state boundary between Connecticut and New York in Long Island Sound was generated using the latitude and longitude coordinates from Source 5 - State boundary coordinates. This line feature was subsequently added to the Town Master for USGS layer. Next, the end points of the state boundary line features offshore Greenwich and Stonington that were based on information from the USGS topographic quadrangle map were tied (moved) to connect to the two end points of the line feature representing the state boundary line between Connecticut and New York in Long Island Sound. This resulted in a fully connected state boundary line feature in Long Island. Additionally, town boundaries separating coastal towns in Long Island Sound are depicted on only some of USGS topographic quadrangle maps. In an attempt to enclose all town polygons in Long Island Sound, portions of the boundaries in Long Island Sound for the following shoreline towns were made to trend due south from their end point as depicted on the USGS topographic quadrangle map until they intersected the Connecticut - New York boundary in the middle of Long Island Sound: Greenwich, Stamford, Darien, Norwalk, Westport, Fairfield, Bridgeport, Stratford, Milford, West Haven, New Haven, East Haven, Branford, Guilford, Madison, Clinton, Westbrook, Old Saybrook, Old Lyme, East Lyme, and Waterford. These particular line features do not represent real town boundaries and are encoded with a TBARC_COD attribute value of zero (0), signifying a Closure Line. In short, all boundary line features are based on the USGS topographic quadrangle maps, with the exception of (1) most of the state boundary in Long Island Sound, which is based on latitude and longitude coordinates and (2) portions of some of the town boundaries in Long Island Sound, which were estimated to trend south from their end point as depicted on the USGS topographic quadrangle map. Final polygon and line feature topology was established with ArcInfo Fuzzy and Dangle tolerances verified at 4 and 10 feet, respectively. At this step in the process the Town Master from USGS layer was fully attributed and ready for use. Not all data fields from the original DLG files were preserved by this step in the process. A new data field, AV_LEGEND, was added to more easily classify and cartographically represent features when mapping and displaying the information with software such as ArcView.
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Datum conversion - Using ESRI ArcInfo software, the Town Master from USGS layer was converted from the Connecticut State Plane Coordinate System of 1927 (NAD27) to the Connecticut State Plane Coordinate System of 1983 (NAD83). The NADCON (North American Datum CONversion) data transformation was used.
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Boundary Correction between Middletown and Portland - The town boundary between Middletown and Portand was changed from its location 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.
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Attribute enhancements - AV_LEGEND, TOWN_POLY, TOWN_ARC, COAST_POLY, and COAST_ARC attributes were modified from storing abbreviated values in upper case to full length values in both upper and lower case. Additionally, the IMS_LEGEND attribute was added to establish a simple feature classification scheme for symbolizing Town Master from USGS features with Internet mapping software environments such as ArcIMS.
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Attribute Integrity Improvements - Using Arc Macro Language (AML), an automated process (MAKECOVER.AML) was developed to maintain consistent attribute values by programmatically joining lookup data tables to decode numeric code fields and encoding the following line attributes based on the topological relationships between the line and polygon features: STATE_FLG, FIPS_FLG, CONN_FLG, TOWN_FLG, CITY_FLG, BORO_FLG, CNTY_FLG, TNO_LEFT, TOWN_LEFT, TNO_RIGHT, TOWN_RIGHT, CITY_LEFT, and CITY_RIGHT. For example, given that each line feature inherently has a (from-to) direction, the value for the TNO_LEFT (Town Number Left) line attribute is based the value of the TOWN_NO (Town Number) attribute for the polygon to the left of the boundary line feature. And the TNO_RIGHT (Town Number Right) line attribute is based the value of the TOWN_NO (Town Number) attribute for the polygon to the right of the boundary line feature. The direction of the line feature is arbitrary and usually reflects the direction with which the feature was digitized. Additionally, the MAKECOVER.AML also encoded Boolean type fields that flag certain types of features such as county boundaries. For example, the CNTY_FLG (Connecticut County Boundary Flag) field stores either a value of "True" or "False" to distinguish county boundaries from other boundaries and is attributed by comparing the value of the CNTY_COD (Connecticut County Code) attribute of the polygon to the left and right of every line feature. If the CNTY_COD polygon attribute values differ, then the line feature is a county boundary and the CNTY_FLG line attribute is assigned a value of "true". In 2005, all Boolean fields such as STATE_FLG, FIPS_FLG, CONN_FLG, TOWN_FLG, CITY_FLG, and BORO_FLG were converted from storing previously used 1 an 0 numeric values to represent true and false conditions to storing "True" and "False" text string values, respectively. The name of the resulting ArcInfo coverage created by this automated process is TOWNUSGS.
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Create 2005 Edition of Town Master from USGS - The automated process (software program), MAKECOVER.AML, developed for the previous process step was executed in 2005 in order to create a 2005 edition (copy) of Town Master From USGS that captures recent corrections and enhancements made to the layer. The MAKECOVER.AML program was last run in 2005, and the name of the resulting ArcInfo coverage created by this automated process is TOWNUSGS.
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Export to Shapefile format - Converted polygon feature data from an ArcInfo coverage named TOWNUSGS to a Shapefile named Town_Master_USGS_Poly.shp. Excluded the AREA, PERIMETER, TOWNUSGS#, and TOWNUSGS-ID attributes from the Shapefile because their values are only maintained by ArcInfo software with spatial data that is ArcInfo coverage format.
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Convert to GeoDatabase Feature Class format - Defined new Feature Class named Town_Master_USGS_Poly; and imported the attribute definitions, loaded features and imported metadata from Town_Master_USGS_Poly.shp shapefile. Spatial Reference Properties for Feature Class: Coordinate System: NAD_1983_StatePlane_Connecticut_FIPS_0600_Feet XY Domain MinX: 100000; MaxX: 2247483.645 XY Domain MinY: 200000; MaxY: 2347483.645 Precision: 1000
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Create Connecticut Towns for Identify layer - Polygon features from the layer named 'Connecticut Town Master from USGS' were copied to a personal geodatabase feature class having the same name (Town_Master_USGS_Poly). Subsequently, all polygon features not located in Connectcut (STATE_COD <> 'CT') were deleted from this feature class. A final dissolve of features on the STATE_COD, FIPS_COD, TOWN_NO, TOWN, CNTY_COD, and COUNTY attributes merged (adjacent) features of the same town/county, resulting in 169 town polygons that covered the land and waters of Connecticut in a new feature class named Town_Identify.
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These data retain the feature geometry and basic attributes of polygon features for town areas identified by the USGS, extending these areas for coastal towns in Long Island Sound. All attributes have valid values. Values are within defined domains. The STATE_COD, FIPS_COD, TOWN_NO, TOWN, CNTY_COD, and COUNTY polygon attributes were manually entered, visually inspected and compared to information on the USGS 7.5 minute topographic quadrangle maps.
Boundaries on the land shown on USGS topographic quadrangle maps (and not in Long Island Sound) comply 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.
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.
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. 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).
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 Connecticut Towns for Identify layer, compiled and published by CT DEP and USGS. Source map scale is 1:24,000.
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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.
| Data format: | in format Shapefile, Feature Class (version ArcGIS) |
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| Network links: | http://www.ct.gov/deep |
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.
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