Migratory Waterfowl is a 1:24,000-scale, polygon feature-based layer that depicts the concentration areas of migratory waterfowl at specific locations within Connecticut. Paul Merola, former DEP Wildlife Biologist, and Greg Chasko, DEP Wildlife Biologist, identified the migratory waterfowl concentration areas based on the Northeast Coastal Areas Study, Joseph Dowhan, 1991 (see Supplemental Information) as well as by using midwinter surveys, breeding surveys and personal observations. The concentration areas are primarily found along the shoreline and the lower tributaries and wetlands of major Connecticut rivers. In addition to depicting the concentration areas, the potential waterfowl species associated with each polygon have been identified and are listed in the attribute table as boolean values indicating their presence or absence. The intent of this datalayer is to assist in the identification of migratory waterfowl resource areas in the event of an oil spill or other condition that might be a threat to waterfowl species. This layer identifies conditions at a particular point in time. It is not updated and it is not a complete representation of all areas of migratory waterfowl in Connecticut.

Redistricting is the process used to evaluate the map
boundaries of U.S. Congressional and state legislative districts and, as
necessary, redraw them to ensure each district includes a substantially equal
number of people.  Each Congressional, State
Senate, or State House district can be said to have an “ideal” number of
residents.  The “ideal” population is
simply the number that results from dividing the State’s total population by
the number of districts for the given legislative body.  For example, Connecticut’s “ideal”
Congressional district size is 721,189, which is the CT population as counted
by the 2020 US Census divided by its 5 Congressional districts.

In Connecticut, the State Legislature is primarily
responsible for drawing both congressional and state legislative district
lines. Maps must be approved by a two-thirds vote in each chamber. If the State
Legislature is unable to approve new maps, a backup commission is convened to
draw congressional and state legislative district boundaries. The commission
consists of nine members. The four legislative leaders appoint two members
each. The ninth member is selected by the eight previously selected
commissioners.

The Coastal Boundary layer is a 1:24,000-scale, polygon feature-based layer of the legal mylar-based maps adopted by the Commissioner of the Department of Environmental Protection (DEP) (i.e., maps were adopted on a town by town basis) showing the extent of lands and coastal waters as defined by Connecticut General Statute (C.G.S.) 22a-93(5)) within Connecticut's coastal area (defined by C.G.S. 22a-94(c)). The coastal boundary is a hybrid of the original 1:24,000 version maps prepared by DEP consistent with C.G.S. 22a-94(d) (Coastal Area) and the revised boundary mapping undertaken by twenty-two coastal towns prepared pursuant to C.G.S. 22a-94(f). This layer therefore does not replace the legal maps and may not be used for legal determinations.
The Coastal Boundary layer includes a single polygon feature that represents the coastal boundary. No other features are included in this layer. Data is compiled at 1:24,000 scale. Attribute information is comprised of an Av_Legend attribute and a CoastB_Flg attribute to denote the coastal boundary. Other attributes include automatically calculated Shape_Length and Shape_Area fields. This data is not updated.
Any regulated activity conducted within the coastal boundary by a municipal agency (i.e., plans of development, zoning regulations, municipal coastal programs and coastal site plan review (i.e., site plans submitted to zoning commission, subdivision or resubdivision plans submitted to planning commission, application for special permit or exception to the zoning or planning commissions or zoning board of appeals, variance submitted to zoning board of appeals and a referral of a municipal project)) must be conducted in a manner consistent with the requirements of the Connecticut Coastal Management Act (CMA; C.G.S. 22a-90 to 22a-113). As the Coastal Boundary is a hybrid of the Coastal Area, all state and federal agency activities must be consistent with the requirements of the CMA.
As defined in C.G.S. 22a-94(b) the coastal boundary is a "continuous line delineated on the landward side by the interior contour elevation of the one hundred year frequency coastal flood zone, as defined and determined by the National Flood Insurance Act, as amended (USC 42 Section 4101, P.L. 93-234), or a one thousand foot linear setback measured from the mean high water mark in coastal waters, or a one thousand foot linear setback measured from the inland boundary of tidal wetlands mapped under section 22a-20, whichever is farthest inland; and shall be delineated on the seaward side by the seaward extent of the jurisdiction of the state."
The original boundary maps were created in 1979 on stable mylar overlay using the 1:24,000-scale US Geological Survey topographic quadrangle maps (mylar film format). The source for tidal wetland maps were the legal 1:24,000 maps (mylar format) adopted by the Commissioner of DEP and transformed to 1:24,000 mylar-scale maps by the Office of Policy and Management (OPM) using an accurate pantograph. OPM similarly converted FEMA's flood insurance maps (various scales) to a 1:24,000 mylar overlay. The inland extent of coastal waters was plotted on 1:24,000 USGS topographic maps following the procedures and sources described in The Boundary Between Saltwater and Freshwater in Connecticut, December 1978 prepared by the State of Connecticut, Department of Environmental Protection, Coastal Area Management Program.
The following twenty-two towns have adopted municipal coastal boundaries: Chester, Clinton, Darien, Deep River, East Haven, Essex, Fairfield, Greenwich, Groton, Guilford, Hamden, Ledyard, Madison, Milford, New Haven, New London, North Haven, Norwalk, Old Lyme, Old Saybrook, Stamford and Waterford. The coastal boundary maps for these towns may be at different scales than the original DEP draft maps and may contain minor adjustments to the boundary as permitted in C.G.S. 22a-94(f).

LIS Dredged Material Disposal Sites is a polygon feature-based layer that depicts the official locations of the four active (currently used) sites for depositing sediments approved for open water disposal in Long Island Sound. It does not include historic or discontinued disposal sites. The layer was compiled initially between 1999 and 2001 and depicts current conditions. Compilation scale is unknown. Attribute information is comprised of codes to uniquely identify individual features (locations of dredge disposal sites), encode the features, and cartographically represent (symbolize) these features on a map. This layer is updated as needed.
Disposal activities in Long Island Sound are regulated by the following Federal statutes: the Clean Water Acts of 1977, the Coastal Zone Management Act, the Endangered Species Act of 1973, the Marine Protection, Research, and Sanctuaries Act of 1972, the National Environmental Policy Act of 1969, the Fish and Wildlife Coordination Act of 1958, and the Rivers and Harbors Act of 1899. In addition to Federal oversight, both Connecticut and New York also regulate open water disposal in the waters of Long Island Sound. In Connecticut, authority stems from the state's Structures, Dredging and Fill statute, the Tidal Wetlands statute, and the Connecticut Coastal Management Act. In New York, disposal is regulated through the Use and Protection of Waters Regulation, the Tidal Wetlands Use Regulations, the Coastal Erosion Management Regulations, the State Environmental Quality Review Act, the State Historic Preservation Act, the Waterfront Revitalization and Coastal Resources Act, and the New York Coastal Management Program.
The practice of open water disposal in Long Island Sound utilizes one of the following management strategies:
1. Unconfined Open Water Disposal: A process by which material deemed to be environmentally safe is deposited at a given site.
2. Confined Open Water Disposal: A process by which sediments not suitable for unconfined open water disposal are deposited and then covered or "capped" with environmentally safe material. A variation of this method occurs when previous sediment mounds are used to form a ring into which material not suitable for unconfined open water disposal can be placed and then capped accordingly.
The datalayer was originally created from information provided by: (1) Carey, D., Valente R., Murray P., and Rhoads, D. 1998. State of Connecticut Dept. of Environmental Protection Office of Long Island Sound Programs Dredged Sediment Management Study: Long Island Sound Dredged Material Management Approach. SAIC Peport No. 442, Science Applications International Corporation. Appendix F.; and (2) Various US ACOE DAMOS Monitoring Cruise Reports, 1991-2000. Updates for the 2005 edition included information from The Final Rulemaking and Response to Comments Document for the Final Environmental Impact Statement (FEIS) for the Designation of Dredged Material Disposal Sites in Central and Western Long Island Sound, US Environmental Protection Agency, May 19, 2005.

As part of the overall management approach, the four sites have been extensively monitored by the US Army Corps of Engineer's (ACOE) Disposal Area MOnitoring System (DAMOS) since 1977. Each site is briefly summarized as follows:
Western Long Island Sound Disposal Site: The Western Long Island Sound Disposal Site (WLIS) is located 4.63 km south of Long Neck Point, CT. Dredged material has been deposited annually at the 5.35 km2 site since 1982 and consists mainly of fine silts and clays. Sensitive local resources and public concern limit disposal to material with only low levels of contamination, therefore, only unconfined open water disposal is employed. WLIS has been extensively monitored by the DAMOS program since the mid 1980's. Feature data updated as of 2005.
Central Long Island Sound Disposal Site: The Central Long Island Sound Disposal Site (CLIS) was designated in 1979 and incorporates a previous disposa

Connecticut Historic Shoreline Wetlands:

1880s NOS T-Sheet Shoreline Features is a 1:10,000-scale, line feature-based layer that includes information depicting historic shoreline features and wetland boundaries for areas of coastal Connecticut during the 1880s. The layer depicts information found on topographic survey sheets (T-sheets) from the US Coast and Geodetic Survey (USC&GS), a predecessor to the National Ocean Service (NOS). The layer represents conditions at a particular point in time. The layer does not depict current conditions. The layer includes ground condition features such as approximate shoreline, shoreline, wetland shoreline, wetland upland boundaries, wetland interior boundaries, man-made shoreline, jetties/breakwaters/groins, and piers/ramps/docks. Semi-submerged marshes, referred to here as "low marshes," ocurring where it is possible to discern marsh-like features waterward of the shoreline are also included. Off shore and riverine islands and rocks may be included depending on the quality of their depiction on the t-sheet. It does not include any non shoreline-centric elements that may have been depicted on the t-sheets such as buildings, roads, bridges, etc., nor does it include other off-shore features like sandbars, mud flats, tidal flats, etc. Features are line locations that represent the approximate location of shoreline features and wetland boundaries. Shoreline, as depicted on the T-sheets that pre-date 1927, reference an approximation of Mean High Water (MHW). Although MHW is technically determined by averaging the height of the high water line, (HWL) the landward extent of the last high tide over a 19 year lunar cycle, USC&GS topographers appoximated MHW by familarizing themselves with the tidal conditions in a given area and noting the assorted physical characteristics of the beach. (For a more complete description of this and other shoreline indicators, the reader is directed to the following article: "Historical Shoreline Change: Error Analysis and Mapping Accuracy," Crowell, M., Leatherman, S., and Buckley, M. Journal of Coastal Research, Vol 7, No. 3, 1991, pp 839-852.)
Attribute information is comprised of codes to identify individual features, encode shoreline feature type information, and cartographically represent (symbolize) shoreline features on a map. These codes were derived in part from the National Oceanic & Atmospheric Administration (NOAA) Coastal Services Center (CSC) Historic Digital Shoreline Capture project and modified by the State of Connecticut Department of Environmental Protection to address the inclusion of wetland areas. This data was compiled at 1:10,000 scale. This data is not updated.
Purpose: 1880s NOS T-Sheet Shoreline Features is 1:10,000-scale data. It depicts the location of historic shoreline features and wetland boundaries for all of coastal Connecticut with the exception of the area of New Haven Harbor from the West River in West Haven to the New Haven/East Haven town boundary. The features also extend slightly beyond the Connecticut state lines into Rye, New York and Westerly, Rhode Island. Use this layer to display historic shoreline and wetlands. Since this data may be considered a crucial element in land use planning, determination of boundary extents, performing change studies for erosion and accretion examinations and other types of decision making this layer may also be used for analytic purposes. Use this layer with other 1:10,000-scale map data such as any other NOS T-sheet Shoreline or Wetland layers. Not intended for maps printed at map scales greater or more detailed than 1:10,000 scale (1 inch = 833.33 feet.)

1880s NOS T-Sheet Wetland Polygon Features is a 1:10,000-scale, polygon feature-based layer that includes information depicting historic wetlands for areas of coastal Connecticut during the 1880s. The layer depicts information found on topographic survey sheets (T-sheets) from the US Coast and Geodetic Survey (USC&GS), a predecessor to

A standardized mapping of natural drainage basins in Connecticut was completed in 1981 by the Connecticut Department of Environmental Protection (DEP). This drainage basin system divided Connecticut into 8 major basins, 45 regional basins, 337 subregional basins, 2,898 local basins, and 7,067 small drainage basin areas. The statewide mapping of natural drainage basins established a hierarchical system of basins based on drainage area size with large major basins subdivided into regional basins, regional basins subdivided into subregional basins, subregional basins subdivided into local basins, and local basins subdivided into smaller and more numerous drainage basin areas. It includes watersheds for Connecticut rivers, streams, brooks, lakes, reservoirs and ponds included on 1:24,000-scale 7.5 minute topographic quadrangle maps published by the U.S. Geological Survey (USGS) between 1969 and 1984. These basin units include smaller watersheds that drain into many of the small streams and ponds in Connecticut. These basin areas are the building blocks for the larger local, subregional, regional and major drainage basins defined by DEP.

Connecticut Subregional Drainage Basins includes 337 drainage basin areas, the majority of which range from 5 to 70 square miles in size and make up, in order of increasing size the larger regional and major drainage basin areas. The subregional basin number (SBAS_NO) uniquely identifies individual subregional drainage basins and is 4 characters in length. There are 335 unique subregional basin numbers. Examples include 6000 for the Housatonic River Main Stem Subregional Basin, 4300 for the Farmington River Subregional Basin, and 6002 for the Schenob Brook Subregional Basin. The first digit (column 1) designates the major basin, the first two digits (columns 1-2) designate the regional basin, and the first 4 digits (columns 1-4) designate the subregional basin. Note, there are slightly more subregional basin areas delineated (374) than unique subregional basin numbers (335) primarily due to a few stream confluences that split the same local basin into two areas. Refer to the Connecticut Subregional Drainage Basin GIS metadata for more information about drainage basin numbers.

Included with the subregional drainage basin boundaries are Subregional Drainage Basins Direction arrows that depict the general direction of surface water flow towards indivicual subregional drainage basin outlets. Theses arrows are meant to indicate where one basin drains into another and are intended aid in visualizing the network of subregional drainage basins in Connecticut. They do not depict the exact location of basin outlets.

These basin boundaries are the digital equivalent of the major, regional and subregional drainage basin boundaries published on the 1:125,000-scale state map entitled Natural Drainage Basins in Connecticut, McElroy, 1981.

The Long Island Sound Submerged Cable and Pipeline Areas layer is a polygon feature-based layer that includes the location of submerged cable and/or pipeline areas in Long Island Sound. These can include, but are not necessarily limited to: electric transmission lines, telephone and/or fiber optic cables, natural gas and/or petroleum pipelines, etc. The layer is based on information from the 2002 edition of digital National Oceanic & Atmospheric Administration (NOAA) nautical charts provided by Maptech, Inc., a field survey completed by Ocean Surveys Inc (OSI) in 2002, and the *proposed* location of a pipeline from plans provided by Broadwater Energy in 2005. The Long Island Sound Submerged Cable and Pipeline Areas layer was originally created during the summer of 2002. The layer represents conditions at particular points in time. The layer includes representations of areas of underwater cables and/or pipelines. It does not include cable and/or pipeline areas landward of mean high water, nor does it include all possible submerged cables, pipelines, or other similar features. Features are polygon locations that represent the approximate or assumed location of cables and/or pipelines for the purpose of cartographic representation and general planning. Attribute information is comprised of codes to uniquely identify individual features, encode cable/pipeline type of information, and cartographically represent (symbolize) cable/pipeline features on a map. Data is compiled at 1:20,000 and 1:24,000 scale. This data is not planned for regular updates. Last updated 10/4/2005

See full Data Guide here. This layer includes polygon features that depict protected open space for towns of the Protected Open Space Mapping (POSM) project, which is administered by the Connecticut Department of Energy and Environmental Protection, Land Acquisition and Management. Only parcels that meet the criteria of protected open space as defined in the POSM project are in this layer. Protected open space is defined as: (1) Land or interest in land acquired for the permanent protection of natural features of the state's landscape or essential habitat for endangered or threatened species; or (2) Land or an interest in land acquired to permanently support and sustain non-facility-based outdoor recreation, forestry and fishery activities, or other wildlife or natural resource conservation or preservation activities. Includes protected open space data for the towns of Andover, Ansonia, Ashford, Avon, Beacon Falls, Canaan, Clinton, Berlin, Bethany, Bethel, Bethlehem, Bloomfield, Bridgewater, Bolton, Brookfield, Brooklyn, Canterbury, Canton, Chaplin, Cheshire, Colchester, Colebrook, Columbia, Cornwall, Coventry, Cromwell, Danbury, Derby, East Granby, East Haddam, East Hampton, East Hartford, East Windsor, Eastford, Ellington, Enfield, Essex, Farmington, Franklin, Glastonbury, Goshen, Granby, Griswold, Groton, Guilford, Haddam, Hampton, Hartford, Hebron, Kent, Killingworth, Lebanon, Ledyard, Lisbon, Litchfield, Madison, Manchester, Mansfield, Marlborough, Meriden, Middlebury, Middlefield, Middletown, Monroe, Montville, Morris, New Britain, New Canaan, New Fairfield, New Milford, New Hartford, Newington, Newtown, Norfolk, North, Norwich, Preston, Ridgefield, Shelton, Stonington, Oxford, Plainfield, Plainville, Pomfret, Portland, Prospect, Putnam, Redding, Rocky Hill, Roxbury, Salem, Salisbury, Scotland, Seymour, Sharon, Sherman, Simsbury, Somers, South Windsor, Southbury, Southington, Sprague, Sterling, Suffield, Thomaston, Thompson, Tolland, Torrington, Union, Vernon, Wallingford, Windham, Warren, Washington, Waterbury, Watertown, West Hartford, Westbrook, Weston, Wethersfield, Willington, Wilton, Windsor, Windsor Locks, Wolcott, Woodbridge, Woodbury, and Woodstock. Additional towns are added to this list as they are completed. The layer is based on information from various sources collected and compiled during the period from March 2005 through the present. These sources include but are not limited to municipal Assessor's records (the Assessor's database, hard copy maps and deeds) and existing digital parcel data. The layer represents conditions as of the date of research at each city or town hall. The Protected Open Space layer includes the parcel shape (geometry), a project-specific parcel ID based on the Town and Town Assessor's lot numbering system, and system-defined (automatically generated) fields. The Protected Open Space layer has an accompanying table containing more detailed information about each feature (parcel). This table is called Protected Open Space Dat, and can be joined to Protected Open Space in ArcMap using the parcel ID (PAR_ID) field. Detailed information in the Protected Open Space Data attribute table includes the Assessor's Map, Block and Lot numbers (the Assessor's parcel identification numbering system), the official name of the parcel (such as the park or forest name if it has one), address and owner information, the deed volume and page numbers, survey information, open space type, the unique parcel ID number (Par_ID), comments collected by researchers during city/town hall visits, and acreage. This layer does not include parcels that do not meet the definition of open space as defined above. Features are stored as polygons that represent the best available locational information, and are "best fit" to the land base available for each.

The Connecticut Department of Environmental Protection's (CTDEP) Permanently Protected Open Space Phase Mapping Project Phase 1 (Protected Open Space Phase1) layer

Ground Water Classifications Polygon:

Ground Water Quality Classifications is a polygon feature-based layer compiled at 1:24,000 scale that includes water quality classification information for groundwaters for all areas of the State of Connecticut. Ground Waters means waters flowing through earth materials beneath the ground surface and the Ground Water Quality Classifications is a designation of the use of the ground waters. The Ground Water Quality Classifications is based primarily on the Adopted Water Quality Classifications Map sheets with information collected and compiled from 1986 to 1997 by major drainage basin. The maps were hand-drawn at 1:50,000-scale in ink on Mylar which had been underprinted with a USGS topographic map base. The digital layer includes ground water water quality classifications. It does not include water quality classifications for ground waters below surface waterbodies. Surface Water Quality Classifications are defined separately in a set of data layers comprised of line and polygon features. The Ground Water Quality Classifications and the Surface Water Quality Classifications are usually presented together as a depiction of water quality classifications in Connecticut. The Ground Water Quality Classes are GA, GAA, GAAs, GB and GC. Classes GAA and GA designate areas of existing or potential drinking water. All ground waters not otherwise classified are considered as Class GA. Class GAAs is for ground water that is tributary to a public water supply reservoir. Class GB is used where ground water is not suitable for drinking water. Class GC is used for assimilation of permitted discharges. Modified classes GA-Impaired, GAA-Impaired, GAA-Well-Impaired, GAA-Well and GA-NY are found in the data layer to categorize special cases of GA or GAA that may not be meeting the goal (impaired), surround public water supply wells (Well) or contribute to a public water supply watershed for another state (NY).
There are three elements that make up the Water Quality Standards which is an important element in Connecticut's clean water program. The first of these is the Standards themselves. The Standards set an overall policy for management of water quality in accordance with the directive of Section 22a-426 of the Connecticut General Statutes. In simple terms the policies can be summarized by saying that the Department of Energy and Environmental Protection shall: Protect surface and ground waters from degradation, Segregate waters used for drinking from those that play a role in waste assimilation, Restore surface waters that have been used for waste assimilation to conditions suitable for fishing and swimming, Restore degraded ground water to protect existing and designated uses, Provide a framework for establishing priorities for pollution abatement and State funding for clean up, Adopt standards that promote the State's economy in harmony with the environment. The second element is the Criteria, the descriptive and numerical standards that describe the allowable parameters and goals for the various water quality classifications. The final element is the Classification Maps that show the Class assigned to each surface and groundwater resource throughout the State. These maps also show the goals for the water resources, and in that manner provide a blueprint and set of priorities for Connecticut's efforts to restore water quality. Although federal law requires adoption of Water Quality Standards for surface waters, Water Quality Standards for ground waters are not subject to federal review and approval. Connecticut's Standards recognize that surface and ground waters are interrelated and address the issue of competing use of ground waters for drinking and for waste water assimilation. These Standards specifically identify ground water quality goals, designated uses