Connecticut Named Waterbody Polygon includes the polygon features of a layer named Named Waterbody. Named Waterbody is a 1:24,000-scale, polygon and line feature-based layer that includes all named waterbodies depicted on the U.S. Geological Survey (USGS) 7.5 minute topographic quadrangle maps for the State of Connecticut. This layer only includes features located in Connecticut. Named Waterbody features include water, dams, flow connectors, aqueducts, canals, ditches, shorelines, and islands. The layer does not include the marsh areas, tidal flats, rocks, shoals, or channels typically shown on USGS 7.5 minute topographic quadrangle maps. However, the layer includes linear (flow) connector features that fill in gaps between river and stream features where water passes through marshes or underground through pipelines and tunnels. Note that connectors represent general pathways and do not represent the exact location or orientation of actual underground pipelines, tunnels, aqueducts, etc. The Named Waterbody layer is comprised of polygon and line features. Polygon features represent areas of water for rivers, streams, brooks, reservoirs, lakes, ponds, bays, coves, and harbors. Polygon features also depict related information such as dams and islands. Line features represent single-line rivers and streams, flow connectors, aqueducts, canals, and ditches. Line features also enclose all polygon features in the form of shorelines, dams, and closure lines separating adjacent water features. The Named Waterbody layer is based on information from USGS topographic quadrangle maps published between 1969 and 1984 so it does not depict conditions at any one particular point in time. Also, the layer does not reflect recent changes with the course of streams or location of shorelines impacted by natural events or changes in development since the time the USGS 7.5 minute topographic quadrangle maps were published. Attribute information is comprised of codes to identify waterbody features by type, cartographically represent (symbolize) waterbody features on a map, select waterbodies appropriate to display at different map scales, identify individual waterbodies on a map by name, and describe waterbody feature area and length. The names assigned to individual waterbodies are based on information published on the USGS 7.5 minute topographic quadrangle maps or other state and local maps. The Named Waterbody layer does not include bathymetric, stream gradient, water flow, water quality, or biological habitat information. Derived from the Hydrography layer, the Named Waterbody layer was originally published in 1999. The 2005 edition includes the same water features published in 1999, however some attribute information has been slightly modified and made easier to use. Also, the 2005 edition corrects previously undetected attribute coding errors and includes the flow connector features.

The Connecticut Named Waterbody layer is 1:24,000-scale base map data. It depicts the location of all waterbodies published on the USGS topographic quadrangle maps that are named with flow connectors to fill in gaps primarily where water flows through marshes or underground through pipelines. It is intended to be used as the portion of a base map that emphasizes the more widely known waterbodies in Connecticut at 1:24,000 scale. Use this layer with other 1:24,000-scale base map data such as Roads and Trails, Railroads, Airports, and Towns.  Also use this layer to display named waterbodies at smaller map scales by restricting features for display according to value of the Scale Level attribute. The Named Waterbody layer is derived from the Hydrography layer, which is also published by the State of Connecticut, Department of Environmental Protection. The Named Waterbody layer only includes waterbodies from the Hydrography layer that are named, without the detailed feature classification of the Hydrography layer that distinguishes intermittent streams, intermittent lakes, ditches, manmade shorelines, canals, tidal flats, submerged rocks, marshes, etc. Use this layer to obtain the size (acreage) for all named reservoirs, lakes, ponds, and larger (double-line) streams published on the USGS topographic quadrangle maps. This layer may be used as a possible data source for other 1:24,000-scale layers with features that must coincide and line up with stream and shoreline features published on the USGS topographic quadrangle maps. For example, the layer includes a set of connecting line features referred to as Coastline Arcs, which define a shoreline between the Connecticut landmass and Long Island Sound. These Coastline Arc features are commonly used to close polygon features in other 1:24,000-scale layers published by the State of Connecticut, Department of Environmental Protection. For example, Coastline Arcs from the original Hydrography layer define the coastline in the Waterbody, Named Waterbody, Towns, Basins, and Bedrock Geology layers. The Named Waterbody layer includes information within Connecticut and is derived from the Named Waterbody Master layer, which includes all similar features depicted on all of the U.S. Geological Survey (USGS) 7.5 minute topographic quadrangle maps that cover the State of Connecticut. Note that related hydrography layers such as Waterbody, Waterbody Master, Named Waterbody, Named Waterbody Master, and Hydrography are all ultimately derived from the polygon and line features of the Hydrography Master layer. Typically, layers derived from Hydrography Master define a subset of polygon and line features for either the geographic area encompassed by all USGS topographic quadrangle maps that cover the State of Connecticut (a master layer) or the geographic area of the State of Connecticut, in which case the layer is clipped to the State boundary. The Named Waterbody layer is not intended for maps printed at map scales greater or more detailed than 1:24,000 scale (1 inch = 2,000 feet.).

In 2004, the State of Connecticut Department of Environmental Protection developed automated procedures to systematically maintain feature topology and attribute integrity for a set of related hydrography data maintained by the agency. These layers include Hydrography Master, Hydrography, Waterbody Master, Waterbody, Named Waterbody Master, and Named Waterbody. Automated procedures were developed using ArcInfo Workstation 8.3 software and the Arc Macro Language (AML) as a scripting environment and recorded in an AML file named MAKECOVER.AML for the hydrography category of data for the State of Connecticut, Department of Environmental Protection. The MAKECOVER.AML derives all related hydrography layers from one Hydrography Master layer. 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.

The named waterbody information incorporated into the Hydrography, Waterbody and Named Waterbody layers was originally compiled and mapped by James Bogar, a Cartographer with the State of Connecticut, Department of Environmental Protection.

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: Hydrography - From the Named Waterbody layer, compiled and published by CT DEP and USGS. Source map scale is 1:24,000.

Includes linear and polygonal features for rivers, streams, brooks, reservoirs, lakes, ponds, bays, coves, harbors, and other areas of water such as the portion of Long Island Sound in the State of Connecticut published on the U.S. Geological Survey 7.5 minute topographic quadrangle maps. Information encoded about features includes two standard symbology classification schemes, waterbody names, flags for named features, levels for mapping at different scales, feature area in acreage, and feature length in miles. Use the AV_LEGEND or the IMS_LEGEND attribute to symbolize features by basic type (water, dam, stream, shoreline). In the Waterbody layer, the values for AV_LEGEND and IMS_LEGEND are identical for all features. To define a layer that only includes named waterbodies, query line and polygon features for NAMED_COD values greater than 0. To define a layer that only includes named lakes, query the line and polygon features for LAKE_NO and LAKE_NO2 values greater than 0. To define a layer that only includes named streams, query the line and polygon features for STREAM_NO and STREAM_NO2 values greater than 0, and so on. To define a layer that only includes the Connecticut River, query line and polygon features for STREAM_NO and STREAM_NO2 equal to 374. The Stream number for the Connecticut River is 374. Each stream, lake, bay, and harbor can be queried by Id number. To define a layer that includes features typically displayed on a map, exclude all unnecessary features by querying the line and polygon 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 Waterbody polygon features that are not outlined on a map. Examples of line features that are not shown include closure lines separating adjacent open water polygons and boundaries defining the bay and harbor extents. Define layers of water to display at different map scale ranges by querying line and polygon features on SCALELEVEL values.

Named Waterbody represented as polygon features. Polygon features represent areas of water for rivers, streams, brooks, reservoirs, lakes, ponds, bays, coves, and harbors. Polygon features also depict related information such as dams and islands.

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.  Both the Hydrography and Named Waterbody layers are complete in the sense that they accurately reflect 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 Hydrography, Waterbody or Named Waterbody layer. So compared to the most recent set of topographic quadrangle maps available today, the Hydrography, Waterbody and Named Waterbody layers are incomplete, and substantially incomplete when compared to waterbodies present today. This data is not updated.

The layer retains the geometry (shape) of hydrography features identified by the USGS without the original detailed classification (type) of hydrography features established by the USGS. This less detailed classification scheme combines features into fewer categories. These broader categories are encoded in the AV_LEGEND and IMS_LEGEND attributes of the Named Waterbody layer. The AV_LEGEND and IMS_LEGEND attributes are derived from the HYARC_COD, HYDRO_ARC, HYPOLY_COD, and HYDRO_POLY attributes of the Hydrography layer and the AV_LEGEND and IMS_LEGEND attributes of  the Named Waterbody Connectors layer. The AV_LEGEND and IMS_LEGEND fields are programmatically attributed by the MAKECOVER.AML, which derives the Named Waterbody layer from the Hydrography layer and Named Waterbody Connectors layer. As part of creating the Hydrography layer, the COASTP_COD and COASTA_COD attribute values were manually entered, and the COAST_POLY and COAST_ARC attributes that decode these values were populated through table joins to lookup tables. These decode values were not manually entered. The COAST_POLY field is the English language equivalent of (decodes) the COASTP_COD field for polygon features. The COAST_ARC field is the English language equivalent of (decodes) the COASTA_COD field for line features. Polygon features were manually selected and populated with STREAM_NO, LAKE_NO, HARBOR_NO, BAY_NO, and SOUND_NO attributes values that identify individually named streams, lakes, harbors, bays and sounds. Named streams represented as a series of single-line features were manually selected and attributed with the corresponding stream number values. The STREAM_NO, STREAM_NO2, LAKE_NO, LAKE_NO2, HARBOR_NO, HARBOR_NO2, BAY_NO, BAY_NO2, SOUND_NO, and SOUND_NO2 for all other line features were attributed through an automated process based on STREAM_NO, LAKE_NO, HARBOR_NO, BAY_NO and SOUND_NO attribute values of the polygon features on the left and right side of line features. For example, shoreline features for all named streams and lakes were attributed with STREAM_NO and LAKE_NO values based on values that were carefully attributed for polygon features that define the waterbody areas. Additional fields that store waterbody names decode these waterbody number values and were populated though table joins to lookup tables.  For example, STREAM decodes STREAM_NO. STREAM2 decodes STREAM_NO2. LAKE decodes LAKE_NO. LAKE2 decodes LAKE_NO2. HARBOR decodes HARB0R_NO. HARBOR2 decodes HARBOR_NO2. BAY decodes BAY_NO. BAY2 decodes BAY_N02. SOUND decodes SOUND_NO. SOUND2 decodes SOUND_NO2.  The NAMEDP_COD and NAMEDA_COD attribute values are based on the values of STREAM_NO, LAKE_NO, BAY_NO, HARBOR_NO, SOUND_NO, and IMS_LEGEND. NAMED_POLY and NAMED_ARC attributes decode these values and were populated though table joins to lookup tables. The NAMED_POLY field decodes the NAMEDP_COD field for polygon features. The NAMED_ARC field decodes the NAMEDA_COD field for line features. The SCALELEVEL field encodes a cartographic preference defined by the State of Connecticut, Department of Environmental Protection for displaying 1:24,000-scale features at different map scales. There are 6 Scale Levels. Each Scale Level represents a chosen set of waterbodies based on STREAM_NO, LAKE_NO, BAY_NO, HARBOR_NO, and SOUND_NO values. The ACREAGE (area in acres) field was 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 in feet.

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 Named Waterbody 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.