Lake Bathymetry is a polygon feature-based layer that includes bathymetric (water depth) information for selected reservoirs, lakes, ponds and coves in Connecticut. The layer is based on information collected by the State of Connecticut, Department of Environmental Protection over a period of time using a variety of different techniques and equipment including manual depth soundings, use of an electronic depth sounder, use of a GPS receiver to locate the boat, and digitizing previously published bathymetry maps. Attribute information is comprised of codes to depict water depth, waterbody indentification, collection method, and to cartographically symbolize features on a map. Data is compiled at a variety of scales and resolutions, depending on the collection method used for a particular waterbody. This data is not updated, however bathymetry information for addtional waterbodies may become available and included in this layer as new information is collected. The Bathymetry layer includes bathymetry for the following Connecticut lakes, ponds and coves: Alexander Lake, Amos Lake, Anderson Pond, Aspinook Pond, Avery Pond, Babcock Pond, Ball Pond, Bantam Lake, Bashan Lake, Batterson Park Pond, Beach Pond, Beachdale Pond, Beseck Lake, Bigelow Pond, Billings Lake, Black Pond, Bolton Lake Lower, Bolton Lake Middle, Bolton Lake Upper, Bolton Notch Pond, Breakneck Pond, Burr Pond, Candlewood Lake, Cedar Lake, Chamberlain Lake, Chapman Pond, Colebrook River Reservoir, Congamond Lakes, Coventry Lake, Cresent Pond, Crow Point Cove, Crystal Lake, Dodge Pond, Dog Pond, Dooley Pond, Eagleville Lake, East Twin Lake, Frash Pond, Gardner Lake, Glasgo Pond, Gorton Pond, Great Hollow Pond, Green Falls Reservoir, Halls Pond, Hamburg Cove, Hampton Reservoir, Hatch Pond, Higganum Reservoir, Highland Lake, Holbrook Pond, Hopeville Pond, Horse Pond, Howells Pond, Jurovaty Pond, Keach Pond, Keeney Cove, Killingly Pond, Lake Hayward, Lake Housatonic, Lake Kenosia, Lake Lillinonah, Lake Of Isles, Lake Saltonstall, Lake Wintergreen, Lake Zoar, Lantern Hill Pond, Leonard Pond, Little Pond, Long Pond, Maltby Lake #1, Maltby Lake #2, Maltby Lake #3, Mamanasco Lake, Mansfield Hollow Reservoir, Mashapaug Lake, McDonough Lake, Messerschmidt Pond, Millers Pond, Mohawk Pond, Mono Pond, Moodus Reservoir Lower, Moodus Reservoir Upper, Moosup Pond, Morey Pond, Mount Tom Pond, Mudge Pond, North Farms Reservoir, Norwich Pond, Pachaug Pond, Park Pond, Pataconk Reservoir, Pataganset Lake, Pickerel Lake, Pine Acres Lake, Powers Lake, Quaddick Reservoir Lower, Quaddick Reservoir Middle, Quaddick Reservoir Upper (Stump Pond), Quinebaug Lake, Quonnipaug Lake, Rainbow Reservoir, Red Cedar Lake, Rogers Lake, Roseland Lake, Salmon Cove, Saugatuck Reservoir, Shenipsit Lake, Silver Lake, South Spectacle Lake, Squantz Pond, Stillwater Pond, Tyler Lake, Uncas Lake, Waramaug Lake, West Branch Reservoir, West Hill Pond, West Side Pond, West Thompson Reservoir, West Twin Lake, Wethersfield Cove, Winchester Lake, Wonoscoponuc Lake, Wood Creek Pond, Wrights Cove, and Wyassup Lake. The 2011 Edition added the following lakes: Allen Brook Pond, Ashland Pond, Barber Pond, Butterworth Dam, Day Pond, Gay City Pond, Lost Pond, Schreeder Pond, Twin Lakes North, Twin Lakes South, Williams Pond.
ground condition
Lake Bathymetry represented as polygon features (Source: of Connecticut, Department of Environmental Protection )
Internal feature number. (Source: ESRI)
Bathymetry Polygon Code - Numeric values that identify bathymetry polygon feature types. (Source: State of Connecticut, Department of Environmental Protection )
| Value | Definition |
|---|---|
| 1 | Water |
| 3 | Island |
| 4 | Marsh |
Bathymetry Polygon Type. Text values that correspond to numeric BATHYP_COD attribute values. BATHY_POLY is the English language equivalent of (decodes) the BATHYP_COD field. (Source: State of Connecticut, Department of Environmental Protection )
ArcView Legend. A text field for symbolizing different feature types on a map. (Source: State of Connecticut, Department of Environmental Protection )
Waterbody Number - ID number of waterbody (lake, cove, etc) in this layer for which there is bathymetry data. (Source: State of Connecticut, Department of Environmental Protection )
Waterbody Name - Name of the waterbody as listed in the publication entitled, A Fisheries Guide to the Lakes and Ponds of Connecticut. Some waterbodies my not be listed in this publication. (Source: State of Connecticut, Department of Environmental Protection )
Waterbody Town - The names of one or more towns the waterbody is located in. (Source: State of Connecticut, Department of Environmental Protection )
Lake Number - ID number of named lake as identified in the Hydrography layer, also published by the State of Connecticut, Department of Environmental Protection. (Source: State of Connecticut, Department of Environmental Protection )
Bay Number - ID number of named bay or cove as identified in the Hydrography layer, also published by the State of Connecticut, Department of Environmental Protection (Source: State of Connecticut, Department of Environmental Protection )
Data Capture Method Code - A numeric code used to denote the general method used in the field to collect water depth information. Different methods were used, depending on techniques available at the time information was collected in the field. (Source: State of Connecticut, Department of Environmental Protection )
| Value | Definition |
|---|---|
| 1 | Manual soundings |
| 2 | Depth finder |
| 3 | GPS and depth finder |
Data Capture Method (Source: State of Connecticut, Department of Environmental Protection )
Data Capture Date - Year bathymetry data was captured (collected) in the field (Source: State of Connecticut, Department of Environmental Protection )
Open Water Depth in Feet - Estimated depth of the water (polygon) based on the depth of the bounding water contour (line) features. The estimated DEPTH_FT value for a water polygon is half the difference between the shallowest and deepest contour. For example, a water polygon bound by a shoreline feature (zero depth) and depth contour of 4 feet is assigned a DEPTH_FT value of 2 feet. (Source: State of Connecticut, Department of Environmental Protection )
Calculated area of polygon feature in acres. Note, ACREAGE values are not automatically updated after modifying feature geometry (shape). Values must be recalculated after features are edited, simplified, generalized, clipped, dissolved, etc. (Source: State of Connecticut, Department of Environmental Protection )
Feature geometry. (Source: ESRI)
Includes bathymetric information such as depth contours, shoreline delineations and depths of areas of open water between contours. Information encoded about these features includes depth, waterbody name, data collection method, and a standard cartographic symbology classification scheme for classifying features on a map. Use the WB_NO field to uniquely identify waterbodies. Use the AV_LEGEND attribute to symbolize features by type on a map. Use the DEPTH_FT line attribute to label depth contours on a map. Use the DEPTH_FT polygon attribute to gradationally shade (symbolize) areas of water according to depth on a map.
Bruce Hunter and Tom Nosal of the State of Connecticut, Department of Environmental Protection developed the techniques and procedures for collecting, processing and preparing bathymetry information collected in the field for use and interpretation. Over a period of time, they systematically created detailed datasets of water depth information using a variety of different techniques. For example, they prepared point data sets of water depth information designed for use with mapping software that generates depth contours. Bill Gerrish, also of the State of Connecticut Department of Environmental Protection processed and edited these detailed datasets of water depth information in order to generate water depth contours for individual lakes and assembled this information into a single, statewide layer.
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This dataset displays the bathymetry (water depth) of selected lakes in Connecticut. Use this layer with hydrography or other waterbody datalayers to display water depth.
The Lake Bathymetry layer retains the feature types and information identified by the State of Connecticut, Department of Environmental Protection. This information was obtained from the previously published bathymetry maps and data. All attributes have valid values. Values are within defined domains. The WB_NO and DEPTH_FT attribute values were assigned to line features through a combination of automated and manual processes. The accuracy test for the WB_NO and DEPTH_FT attributes was conducted by inspecting paper check plots or interactive displays of the data on a computer graphic system by symbolizing, labeling and selecting depth contours by WB_NO and DEPTH_FT values. The value for the DEPTH_FT attribute assigned with open water (polygon) features is based on the depth of the bounding water contour (line) features. The estimated DEPTH_FT value for a water polygon is half the difference between the shallowest and deepest contour. For example, a water polygon bound by a shoreline feature (zero depth) and depth contour of 4 feet is assigned a DEPTH_FT value of 2 feet. DEPTH_FT attribute values for polygon features were manually assigned. AV_LEGEND is a broad classifications of Lake Bathymetry line features . The WBNAME, WBTOWN, LAKE_NO, BAY_NO, METHOD_COD, and DATADATE were not manually entered. These additional fields were populated by joining both the line and polygon feature attribute tables to a lookup data table with WB_NO as the relate key field. This lookup table contained this information for each waterbody. The METHOD value was populated by joining to a lookup table with METHOD_COD as a relate key. The ACREAGE (area in acres) field was automatically calculated for each polygon feature based on computer generated feature area in square feet.
The horizontal positional accuracy of this data is unknown.
The completeness of the data reflects the availability of digital information at the time the layer was published.
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 47.927 feet (fuzzy tolerance) and a minimum allowed overshoot length of 0 feet (dangle length).
No restrictions or legal prerequisites for using the data. 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 as the source for this information.
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| Data format: | in format Shapefile (version ArcGIS 9.3.1) Size: 71.712 |
|---|---|
| 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.
79 Elm Street