Quaternary Geology Feature Set is 1:24,000-scale data that illustrates the geologic features formed in Connecticut during the Quaternary Period, which spans from 2.588 ± 0.005 million years ago to the present and includes the Pleistocene (glacial) and Holocene (postglacial) Epochs. The Quaternary Period has been a time of development of many details of the Connecticut landscape and all surficial deposits. At least twice in the last Pleistocene, continental ice sheets swept across Connecticut from the north. Their effects are of pervasive importance to present-day occupants of the land.

The Quaternary Geology information illustrates the geologic history and the distribution of depositional environments during the emplacement of unconsolidated glacial and postglacial surficial deposits and the landforms resulting from those events in Connecticut. These deposits range from a few feet to several hundred feet in thickness, overlie the bedrock surface and underlie the organic soil layer of Connecticut. Quaternary Geology is mapped without regard for any organic soil layer that may overly the deposit.

For additional documentation including a description of the unconsolidated glacial and postglacial surficial deposits shown on the map, refer to the CT ECO Complete Resource Guide for Quaternary Geology.

The Connecticut Quaternary Geology information was initially compiled at 1:24,000 scale (1 inch = 2,000 feet) then recompiled for a statewide 1:125,000-scale map, Quaternary Geology Map of Connecticut and Long Island Sound Basin (PDF, 56 Mb) Stone, J.R., Schafer, J.P., London, E.H. and Thompson, W.B., 1992, U.S. Geological Survey Special Map, 2 sheets, scale 1:125,000, and pamphlet, 71 p. A companion map, the Surficial Materials Map of Connecticut (PDF, 26 Mb) Stone, J.R., Schafer, J.P., London, E.H., DiGiacomo-Cohen, M.L., Lewis, R.L., and Thompson, W.B., 2005, U.S. Geological Survey Scientific Investigation Map 2784, 2 sheets, scale 1:125,000, emphasizes the surface and subsurface texture (grain-size distribution) of these materials. The quaternary geology and surficial material features portrayed on these two maps are very closely related; each contributes to the interpretation of the other.

DEEP Trails Set:

Trail Access Points are point features in the Statewide Trails Database that describe where trails are accessed at trail heads, state and municipal parks and forests, or other points of departure. Trail Points of Interest are point features in the Statewide Trails Database that describe where there are scenic overlooks, bridges, river crossings or other historic or geologic sites of interest along trails. These features are directly located along trails and do not describe amenities commonly found on park grounds such as parking areas, picnic areas, and restrooms. Trail Point of Interest features are optional. Trails are line features in the Statewide Trails Database that describe the location of single and multi-use trails, access trails, connector trails, and regional trails. These features may also describe bike routes along public roads and their relationship with connecting multi-use paved trails used for walking, running, inline-skating, and bicyling, for example. Trail features describe hiking trails, nature trails, bike routes, and Americans with Disabilities Act (ADA) accessible trails such as certain walkways, boardwalks and stone dust surfaced trails. Individual trail features are described in terms of their surface type (unpaved, paved, unpaved road, paved road, etc.) and whether activities such as hiking, walking, running, inline skating, bicycling, mountain biking, motorbiking, all terraine vehicle use, snowmobiling, cross-country skiing, and horseback riding are permitted. Also indicates whether leashed or unleashed dogs are allowed. Roadway line features are optional features in the Statewide Trails Database used to place a trail system in context with nearby park roads or park entrance. They are very simple line features used to represent driveways, park roads, forest roads, and occasionally public roads on or along the public property where the trail system exists. Roadway line features are optional. They are not used for mapping bike routes. Trail line features are used for mapping bike routes.

Connecticut Mainland Line includes the line features of a layer named Connecticut Mainland. Connecticut Mainland is a 1:24,000-scale, polygon and line feature-based layer that depicts the geographic area encompassed by and the boundary for the State of Connecticut with an additional linear shoreline feature separating the Connecticut mainland from the waters of Long Island Sound. The layer includes a polygon feature representing the Connecticut mainland, a polygon feature representing Connecticut waters in Long Island Sound and approximately 700 polygon features representing Connecticut islands in Long Island Sound. The layer is based on information from USGS topographic quadrangle maps published between 1969 and 1984 and latitude and longitude coordinates that define the boundary between the states of Connecticut and New York in Long Island Sound. Feature length and geographic area are encoded for linear and polygon features, respectively. This layer was originally published in 2005.

Connecticut Mainland Polygon includes the polygon features of a layer named Connecticut Mainland. Connecticut Mainland is a 1:24,000-scale, polygon and line feature-based layer that depicts the geographic area encompassed by and the boundary for the State of Connecticut with an additional linear shoreline feature separating the Connecticut mainland from the waters of Long Island Sound. The layer includes a polygon feature representing the Connecticut mainland, a polygon feature representing Connecticut waters in Long Island Sound and approximately 700 polygon features representing Connecticut islands in Long Island Sound. The layer is based on information from USGS topographic quadrangle maps published between 1969 and 1984 and latitude and longitude coordinates that define the boundary between the states of Connecticut and New York in Long Island Sound. Feature length and geographic area are encoded for linear and polygon features, respectively. This layer was originally published in 2005.

Environmental Justice Block Groups 2021 was created from Connecticut block group boundary data located in the Census Bureau's 2019 TIGER/Line Shapefiles. The poverty data used to determine which block groups qualified as EJ communities (see CT State statute 22a-20a) was based on the Census Bureau's 2019 ACS 5-year estimate- Table C17002. This poverty data was joined with the block group boundaries in ArcMap. Block groups in which the percent of the population below 200% of the federal poverty level was greater than or equal to 30.0 were selected and the resulting selection was exported as a new shapefile. The block groups were then clipped so that only those block groups outside of distressed municipalities were displayed. Maintenance – This layer will be updated annually and will coincide with the annual distressed municipalities update (around August/September). The latest ACS 5-year estimate data should be used to update this layer.

Environmental Justice Distressed Municipalities 2021 was created from Connecticut town boundary data located in the Census Bureau's 2019 TIGER/Line Shapefiles (County Subdivisions). 

Environmental Justice Block Groups 2022 was created from
Connecticut block group boundary data located in the Census Bureau's 2020
TIGER/Line Shapefiles. The poverty data used to determine which block groups
qualified as EJ communities (see CT State statute 22a-20a) was based on the
Census Bureau's 2020 ACS 5-year estimate. This poverty data was joined with the
block group boundaries in ArcPro. Block groups in which the percent of the
population below 200% of the federal poverty level was greater than or equal to
30.0 were selected and the resulting selection was exported as a new shapefile.
The block groups were then clipped so that only those block groups outside of
distressed municipalities were displayed. Maintenance – This layer will be
updated annually and will coincide with the annual distressed municipalities
update (around August/September). The latest ACS 5-year estimate data should be
used to update this layer. Environmental Justice Distressed Municipalities 2020
was created from Connecticut town boundary data located in the Census Bureau's
2020 TIGER/Line Shapefiles (County Subdivisions). 

Connecticut 303(d) Impaired Waters
2022 is a subset of Connecticut 305(b) Assessed Waters 2022. If any one of the
assigned designated uses is categorized as NOT Supporting, the assessed
waterbody is included in this subset and is considered impaired. Additional
information about Integrated Water Quality reporting is available on the CT
DEEP website, Integrated Water
Quality Report page. 

Connecticut 305(b) Assessed Waters
files includes rivers, lakes and estuaries that have been assessed in
compliance with Sections 305(b) and 303(d) of the federal Clean Water Act.
Section 305(b) of the Clean Water Act requires each state to monitor, assess
and report on the quality of its waters relative to attainment of designated
uses established by the State's water quality standards. Section 303(d)
requires each State to compile a subset of that list identifying only those
waters not meeting water quality standards and assign a Total Maximum Daily
Load (TMDL) priority ranking to each impaired waterbody.

This assessment is based on
information collected and compiled prior to 2022. It represents conditions at a
particular point in time and does not represent current conditions. Depending
on the type of waterbody - river, lake, or estuary - this information
geographically displays attainment and non-attainment (e.g. full supporting,
not supporting, not assessed) for each designated use - aquatic life, marine
aquatic life, recreation use, fish consumption, shellfish harvesting, and
drinking water supply.

DEEP Trails Set:

Trail Access Points are point features in the Statewide Trails Database that describe where trails are accessed at trail heads, state and municipal parks and forests, or other points of departure. Trail Points of Interest are point features in the Statewide Trails Database that describe where there are scenic overlooks, bridges, river crossings or other historic or geologic sites of interest along trails. These features are directly located along trails and do not describe amenities commonly found on park grounds such as parking areas, picnic areas, and restrooms. Trail Point of Interest features are optional. Trails are line features in the Statewide Trails Database that describe the location of single and multi-use trails, access trails, connector trails, and regional trails. These features may also describe bike routes along public roads and their relationship with connecting multi-use paved trails used for walking, running, inline-skating, and bicyling, for example. Trail features describe hiking trails, nature trails, bike routes, and Americans with Disabilities Act (ADA) accessible trails such as certain walkways, boardwalks and stone dust surfaced trails. Individual trail features are described in terms of their surface type (unpaved, paved, unpaved road, paved road, etc.) and whether activities such as hiking, walking, running, inline skating, bicycling, mountain biking, motorbiking, all terraine vehicle use, snowmobiling, cross-country skiing, and horseback riding are permitted. Also indicates whether leashed or unleashed dogs are allowed. Roadway line features are optional features in the Statewide Trails Database used to place a trail system in context with nearby park roads or park entrance. They are very simple line features used to represent driveways, park roads, forest roads, and occasionally public roads on or along the public property where the trail system exists. Roadway line features are optional. They are not used for mapping bike routes. Trail line features are used for mapping bike routes.

Connecticut and Vicinity County Boundary data are intended for geographic display of state and county boundaries at statewide and regional levels. Use it to map and label counties on a map. These data are derived from Northeastern United States Political Boundary Master layer.
This information should be displayed and analyzed at scales appropriate for 1:24,000-scale data. The State of Connecticut, Department of Environmental Protection (CTDEP) assembled this regional data layer using data from other states in order to create a single, seamless representation of political boundaries within the vicinity of Connecticut that could be easily incorporated into mapping applications as background information. More accurate and up-to-date information may be available from individual State government Geographic Information System (GIS) offices. Not intended for maps printed at map scales greater or more detailed than 1:24,000 scale (1 inch = 2,000 feet.)

Drainage Basin Set:

Connecticut Drainage Basins is 1:24,000-scale, polygon and line feature data that define natural drainage areas in Connecticut. These are small basin areas that average approximately 1 square mile in size and make up, in order of increasing size, the larger local, subregional, regional, and major drainage basin areas. Connecticut Drainage Basins includes drainage areas for all Connecticut rivers, streams, brooks, lakes, reservoirs and ponds published on 1:24,000-scale 7.5 minute topographic quadrangle maps prepared by the USGS between 1969 and 1984. Data is compiled at 1:24,000 scale (1 inch = 2,000 feet). This information is not updated.
Polygon and line features represent drainage basin areas and boundaries, respectively. Each basin area (polygon) feature is outlined by one or more major, regional, subregional, local, impoundment, or river reach boundary (line) feature. These data include 7,076 basin area (polygon) features and 20,945 basin boundary (line) features.
Basin area (polygon) attributes include major, regional, subregional, local, (full) basin number, and feature size in acres and square miles. The full basin number (BASIN_NO) uniquely identifies individual basins and is up to 13 characters in length. There are 7,031 unique basin numbers. Examples include 6000-00-1+*, 4300-00-1+L1, and 6002-00-2-R1. The first digit (column 1) designates the major basin, the first two digits (columns 1-2) designate the regional basin, the first 4 digits (columns 1-4) designate the subregional basin, and the first seven digits (columns 1-7) designate the local basin. Note, there are slightly more basin polygon features (7,076) than unique basin numbers (7,031) primarily because a few water supply watershed boundaries split a basin into two polygon features at the location of a small dam or point of diversion along a stream.
Basin boundary (line) attributes include a drainage divide type attribute (DIVIDE) used to cartographically represent the hierarchical drainage basin system. This divide type attribute is used to assign different line symbology to major, regional, subregional, local, stream reach, and lake impoundment drainage basin divides. For example, major basin drainage divides are more pronounced and shown with a wider line symbol than regional basin drainage divides.
Connecticut Drainage Basins is the data source for other digital spatial data including the Connecticut Major Drainage Basins, Connecticut Regional Drainage Basins, Connecticut Subregional Drainage Basins, and Connectcut Local Drainage Basins.
Purpose: The polygon features define the contributing drainage area for individual reservoirs, lakes, ponds and river and stream reaches in Connecticut. These are hydrologic land units where precipitation is collected. Rain falling in a basin may take two courses. It may both run over the land and quickly enter surface watercourses, or it may soak into the ground moving through the earth until it surfaces at a wetland or stream. In an undisturbed natural drainage basin, the surface and ground water arrive as precipitation and leave either by evaporation or as surface runoff at the basin's outlet. A basin is a self-contained hydrologic system, with a clearly defined water budget and cycle. The amount of water that flows into the basins equals the amount that leaves. A drainage divide is the topographic barrier along a ridge or line of hilltops separating adjacent drainage basins. For example, rain or snow melt draining down one side of a hill generally will flow into a different basin and stream than water draining down the other side of the hill. These hillsides are separated by a drainage divided that follows nearby hilltops and ridge lines.
Use these basin data to identify where rainfall flows over land and downstream to a particular watercourse. Use these data to cat