Tidal Wetlands 1970's represents the historic regulatory tidal wetland boundaries produced during the early 1970's by the State of Connecticut Department of Agriculture and Natural Resources, which defined the areas of tidal wetlands that were subject to the 1969 Tidal Wetlands Act. The first comprehensive tidal wetlands mapping of the state was undertaken during the 1970's following the passing of the Tidal Wetland Act (TWA) in 1969. The TWA established a permit program to regulate activities conducted in tidal wetlands. The TWA had a mandatory mapping requirement to let property owners know the approximate location of regulated tidal wetland areas. Unfortunately, during the adoption of the regulations, the tidal wetland maps were given greater importance, than was originally intended, such that the maps were used to determine the regulated area rather than the actual site conditions. The mandated revisions to the maps were never undertaken as no additional funding was authorized. (See the Tidal Wetlands 1990's Datalayer for subsequent wetlands mapping.) The regulatory tidal wetland boundaries were surveyed in the field and these boundaries were transferred to 1" = 200' (1: 24000 scale) mylars derived from black and white low altitude aerial photography. It is known that the mapping criteria did change and evolve as the surveyors became more experienced with tidal wetland delineation. It also was not unusual for controversial parcels to be omitted as a result of adverse comments received at public hearings prior to the adoption of the maps. Additionally, no maps were ever produced to show "formerly connected" wetlands, a special type of wetlands. Thus, even at the time of their adoption, the 1970's tidal wetland maps did not include all known tidal wetlands in Connecticut. For more information, please refer to the Tidal Wetlands Report at http://www.ct.gov/dep/lib/dep/gis/coastalresources/tidal_wetlands_report.pdf . The layer does not depict current conditions. It is not updated.
Tidal Wetlands' are defined as follows: 'Tidal Wetlands' means 'wetland' as defined by C.G.S.Sec. 22a-29. C.G.S.Sec.22a-93(7)(E). 'Wetland' means those areas which border or lie beneath tidal waters, such as, but not limited to banks, bogs, salt marshes, swamps, meadows, flats, or other low lands subject to tidal action, including those areas now or formerly connected to tidal waters, and whose surface is at or below an elevation of one foot above local extreme high water; and upon which may grow or be capable of growing some but not necessarily all, of the following: (See the statute for a complete listing of tidally influenced plant species) C.G.S.Sec.22a-29(2). Visit http://www.ct.gov/dep/lib/dep/gis/coastalresources/tidal_wetlands_report.pdf for more information.
ground condition
Tidal Wetlands 1970's represented as polygon features. (Source: State of Connecticut, Department of Environmental Protection)
Internal feature number. (Source: ESRI)
Description of area in terms of wetland or upland. (Source: Connecticut Department of Environmental Protection)
| Value | Definition |
|---|---|
| Upland | Upland area. |
| Tidal Wetland | Tidal wetland area. |
Size of polygon in acres. (Source: Connecticut Department of Environmental Protection)
Feature geometry. (Source: ESRI)
Area of polygon in square feet (Source: ESRI)
Perimeter of polygon in feet. (Source: ESRI)
Includes Tidal Wetland features such as Av_Legend that categorizes the polygon feature as Upland or Tidal Wetland Area. Use the AV_LEGEND attribute to symbolize features by type on a map. Use the Acreage attribute to display the size of the polygon feature in acres.
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Tidal Wetlands 1970's is 1:24,000-scale data. It depicts the location of some (but not all) tidal wetlands circa the late 1960's and early 1070s. Use this layer to depict the location of historic (1970's) wetlands. Not intended for maps printed at map scales greater or more detailed than 1:24,000 scale (1 inch = 2,000 feet.)
Includes field notes and staked points delineating wetland areas as well as wetland maps and aerial photographs used as a base.
This data source refers to all features combined in one statewide layer. Since initial creation, subsequent versions of the layer were generated by the State of Connecticut in order to change data format, OR convert from NAD 27 to NAD 83. Consequently, over the period of many years, different copies of this layer were produced, representing various steps in the datalayer development and maintenance process (metadata lineage). Changes made to the entire layer are reflected in metadata process steps where this particular data source is cited as both the Source Used and the Source Produced.
Regulatory tidal wetland boundaries were delineated in the field and staked. The staked points were transfered to 1"=2000' (1:2400 scale) mylar enlargements derived from unrectified black and white low altitude air photography taken in 1968 at the scale of 1" = 1000' (1:12000 scale). Once on the maps, the points were connected by straight lines to represent an otherwise irregular boundary. Less care was taken when state properties were mapped, resulting in significant areas of open water and upland being included. By 1974 most of these maps were completed and adopted through a hearing process. Fresh and brackish tidal wetlands on the Connecticut River were mapped at a later date but many of these maps were never adopted. When the mapping was completed, there were some tidal wetlands that had been missed or omitted for reasons that are now unknown or because of testimony presented at hearings. It is known that the mapping techniques did improve over time as the biologists became more experienced with wetland delineation. No maps were ever produced to show "formerly connected" wetlands, a special type of regulated wetlands.
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Datum conversion - Using DEPGIS Connecticut NADCON Extension for ESRI ArcView 3 software, the Tidal Wetlands 1970's 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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Export to Shapefile format - Converted polygon feature data from an ArcInfo coverage to Shapefile.
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Export to geodatabase format - Converted polygon feature data from a shapefile to a geodatabase feature class.
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The TIDAL_WETLANDS_1970S layer retains the feature types and information identified by the State of Connecticut, Department of Environmental Protection and obtained from the maps & reports. All attributes have valid values. Values are within defined domains. The accuracy test for the AV_LEGEND attribute values was conducted by comparing the information presented in the source data with 1:24,000-scale check plots or interactive displays of the data on a computer graphic system. These check plot maps and computer displays depicted and labeled the TIDAL_WETLANDS_1970S features in different colors based on AV_LEGEND values for comparison with the original data source. 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. Some features are accurately positioned because the source materials were of sufficient quality and the interpretations refelcted that, and other features are inaccurately positioned because either the source data was not of suffcient quality or the interpretations were flawed..
The completeness of the data reflects the feature content of the data sources, which include the maps, mylars and field data sheets. The TIDAL_WETLANDS_1970S layer is complete in the sense that it accurately reflects the contents of the information available at the time the State of Connecticut, Department of Environmental Protection created the layer. However, compared to current conditions, the TIDAL_WETLANDS_1970S layer is incomplete. 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. Establishment of logical consistency was performed by the State of Connecticut, Department of Environmental Protection using ESRI ArcGIS software to manually create and control feature topology in SHAPEFILE format. No automated procedures or tests were performed to guarantee desired topology other than visual inspection.
None. No restrictions or legal prerequisites for using the data after access is granted. 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 as the source for this information. These data are suitable for planning purposes only, and should not be used to make regulatory or jurisdictional boundary determinations.
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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) |
|---|---|
| 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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