Description: This dataset shows impervious areas of state-owned roadways. These areas were used to calculate total area and percent cover for imperviousness in CT municipalities and DEEP basin areas (see additional datasets). Features identified as state-owned impervious road areas were created using the street centerlines for DOT state roads to identify areas from the 2012 statewide impervious cover data that are owned by the state. Such information is useful for compliance with the State of Connecticut's General Permit for the Discharage of Stormwater from Small Municipal Separate Strom Sewer Systems (MS4).
Copyright Text: University of Connecticut, Center for Land Use Education and Research
Name: Impervious Cover by Watershed Basin (Clipped)
Display Field: BASIN_NO
Type: Feature Layer
Geometry Type: esriGeometryPolygon
Description: Impervious Cover by Watershed Basins is based on the Connecticut Drainage Basins layer and is 1:24,000-scale, polygon feature data that define natural drainage areas in Connecticut and contain values for calculated impervious cover (2012) within each basin. Drainage basins have been clipped to the Connecticut state boundary as well as each municipal boundary. The features are small basin areas that make up, in order of increasing size, the larger local, subregional, regional, and major drainage basin areas. Impervious Cover by Watershed 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 by the Connecticut Department of Environmental Protection (CT DEP) at 1:24,000 scale (1 inch = 2,000 feet). Basin delineation information is not updated. 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 9580 basin areas (polygons), clipped to the boundaries of Connecticut’s 169 municipalities. Impervious cover for each basin area has been calculated from 1-foot impervious cover data (link to metadata). Basin area attributes for imperviousness included total impervious area (acres), percent impervious area, building impervious area (acres and percent), roads (acres and percent) and other impervious area (acres and percent). Road impervious area has also been summarized for state (DOT) road area and non-state owned road area. 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 9580 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 than unique basin numbers 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. Unique basin ID fields (BasinNoU and T_Basin_ID) have been added for the purposes of calculating impervious area. 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 Connecticut Local Drainage Basins.
Copyright Text: Tom Nosal, State of Connecticut, Department of Environmental Protection, for the final compilation and delineation of 1:24,000-scale drainage basin boundaries, assignment of drainage basin numbers, and conversion to digitial format. Basin boundaries were manually delineated at 1:24,000-scale by visually interpreting the 10 feet contour elevation lines and waterbody features appearing on 1:24,000-scale 7.5 minute USGS topographic quadrangle maps for Connecticut published between 1969 and 1984. The metadata abstract includes a brief description of a drainage basin obtained from material written by Jim Murphy in an article entitled Reading the Landscape published in the Citizen's Bulletin, a CT DEP monthy magazine.
University of Connecticut, Center for Land use Education and Research (CLEAR) clipped the basin boundaries to the state of Connecticut and municipal boundaries and calculated all impervious area values.
Description: The stormwater impaired waters layer is based on the 2018 Connecticut Integrated Water Quality Report (IWQR). All waters (rivers, lakes, estuaries) that were listed as impaired (EPA Category 5) in Appendix B-1 of the report and all waters that were listed as having an adopted TMDL in place in Appendix B-2 were identified. Both lists were then compared to the Impaired Waters guidance in Appendix D of the 2017 General Permit for the Discharge of Stormwater from Small Municipal Separate Storm Sewer Systems Reissuance with Modifications. Waters with adopted TMDLs in the 2018 IWQR for the stormwater pollutants of concern listed in Appendix D (phosphorus, nitrogen, bacteria, mercury) of the General Permit and those with a cause listed as ‘Impervious Cover’ were then identified and added to the Stormwater Impaired Waters layer. Impaired waters without a TMDL in the 2018 IWQR were reviewed and those with causes matching the causes listed in Appendix D for each stormwater pollutant of concern were added to the Stormwater Impaired Waters layer. Waters in Appendix B-1 of the IWQR that indicated any of the causes listed for Phosphorus or Nitrogen were listed as impaired for Phosphorus and Nitrogen per DEEP decision. Waters in Appendix B-1 of the IWQR that indicated the impairment cause was ‘Turbidity’ or ‘Unknown’ were listed as impaired for Other pollutant of concern.The resulting list of stormwater impaired waterbodies were then matched up with the Connecticut 303(d) Impaired Waters 2018 (rivers, lakes and estuaries) waterbody features using the waterbody id. Information including stormwater pollutant of concern, cause, impaired designated use and TMDL can be identified by clicking on the layer(s) in the MS4 viewer or with the identify tool in a desktop application. Additional information about Integrated Water Quality reporting is available at the CT DEEP website.
Copyright Text: University of Connecticut, Center for Land Use Education and Research (CLEAR) & CT Department of Energy and Environmental Protection
Description: The stormwater impaired waters layer is based on the 2018 Connecticut Integrated Water Quality Report (IWQR). All waters (rivers, lakes, estuaries) that were listed as impaired (EPA Category 5) in Appendix B-1 of the report and all waters that were listed as having an adopted TMDL in place in Appendix B-2 were identified. Both lists were then compared to the Impaired Waters guidance in Appendix D of the 2017 General Permit for the Discharge of Stormwater from Small Municipal Separate Storm Sewer Systems Reissuance with Modifications. Waters with adopted TMDLs in the 2018 IWQR for the stormwater pollutants of concern listed in Appendix D (phosphorus, nitrogen, bacteria, mercury) of the General Permit and those with a cause listed as ‘Impervious Cover’ were then identified and added to the Stormwater Impaired Waters layer. Impaired waters without a TMDL in the 2018 IWQR were reviewed and those with causes matching the causes listed in Appendix D for each stormwater pollutant of concern were added to the Stormwater Impaired Waters layer. Waters in Appendix B-1 of the IWQR that indicated any of the causes listed for Phosphorus or Nitrogen were listed as impaired for Phosphorus and Nitrogen per DEEP decision. Waters in Appendix B-1 of the IWQR that indicated the impairment cause was ‘Turbidity’ or ‘Unknown’ were listed as impaired for Other pollutant of concern.The resulting list of stormwater impaired waterbodies were then matched up with the Connecticut 303(d) Impaired Waters 2018 (rivers, lakes and estuaries) waterbody features using the waterbody id. Information including stormwater pollutant of concern, cause, impaired designated use and TMDL can be identified by clicking on the layer(s) in the MS4 viewer or with the identify tool in a desktop application. Additional information about Integrated Water Quality reporting is available at the CT DEEP website.
Copyright Text: University of Connecticut, Center for Land Use Education and Research (CLEAR) & CT Department of Energy and Environmental Protection
Description: The stormwater impaired waters layer is based on the 2018 Connecticut Integrated Water Quality Report (IWQR). All waters (rivers, lakes, estuaries) that were listed as impaired (EPA Category 5) in Appendix B-1 of the report and all waters that were listed as having an adopted TMDL in place in Appendix B-2 were identified. Both lists were then compared to the Impaired Waters guidance in Appendix D of the 2017 General Permit for the Discharge of Stormwater from Small Municipal Separate Storm Sewer Systems Reissuance with Modifications. Waters with adopted TMDLs in the 2018 IWQR for the stormwater pollutants of concern listed in Appendix D (phosphorus, nitrogen, bacteria, mercury) of the General Permit and those with a cause listed as ‘Impervious Cover’ were then identified and added to the Stormwater Impaired Waters layer. Impaired waters without a TMDL in the 2018 IWQR were reviewed and those with causes matching the causes listed in Appendix D for each stormwater pollutant of concern were added to the Stormwater Impaired Waters layer. Waters in Appendix B-1 of the IWQR that indicated any of the causes listed for Phosphorus or Nitrogen were listed as impaired for Phosphorus and Nitrogen per DEEP decision. Waters in Appendix B-1 of the IWQR that indicated the impairment cause was ‘Turbidity’ or ‘Unknown’ were listed as impaired for Other pollutant of concern.The resulting list of stormwater impaired waterbodies were then matched up with the Connecticut 303(d) Impaired Waters 2018 (rivers, lakes and estuaries) waterbody features using the waterbody id. Information including stormwater pollutant of concern, cause, impaired designated use and TMDL can be identified by clicking on the layer(s) in the MS4 viewer or with the identify tool in a desktop application. Additional information about Integrated Water Quality reporting is available at the CT DEEP website.
Copyright Text: University of Connecticut, Center for Land Use Education and Research (CLEAR) & CT Department of Energy and Environmental Protection