Connecticut Subregional Drainage Basin Town Intersect is 1:24,000-scale data that is the geographic intersection of subregional drainage basins and towns in Connecticut. It includes polygon features that define where the Connecticut Subregional Drainage Basin Poly and Connecticut Town Polygon layers intersect and overlap each other. The geographic area covered includes the Connecticut mainland and islands along the Connecticut coastline. The total geographic area covered by all polygon features is 4,967.56 square miles. Data is compiled at 1:24,000 scale (1 inch = 2,000 feet). This is static information that is not updated. Polygon feature attributes include basin number and name, town number and name, and feature size in acres and square miles. Each polygon feature includes the 1-digit major (MBAS_NO), 2-digit regional (RBAS_NO), 4-digit subregional (SBAS_NO) drainage basin number, and the Connecticut Town number (TOWN_NO). Subregional drainage basins typically are located in more than one town and a town will include more than one basin. A polygon feature exists for each subregional basin - town occurrence. Connecticut Subregional Drainage Basin Town Intersect is derived from the intersection of the geometry and attributes of the Connecticut Subregional Drainage Basins for Clipping and Connecticut Town Polygon feature classes.
A standardized mapping of natural drainage basins in Connecticut was completed in 1981 by the Connecticut Department of Environmental Protection. 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. Major basins are subdivided into regional basins. Regional basins are subdivided into subregional basins. Subregional basins are subdivided into local basins. Local basins are subdivided into smaller drainage basin areas for impoundments and river reaches. A pair of 1:24,000-scale polygon and line feature classes is available for all basin levels. These data are named Connecticut Major Basins, Connecticut Regional Basins, Connecticut Subregional Basins, Connecticut Local Basins, and Connecticut Drainage Basins. Connecticut Drainage Basins includes the most detailed information upon which the other basin datasets are based. A hierarchical drainage basin number was assigned to uniquely identify drainage basin areas. Drainage basin areas are numbered sequentially beginning upstream and proceeding downstream. The first digit (column 1) identifies the major basin, the first two digits (columns 1-2) identify the regional basin, the first 4 digits (columns 1-4) identify the subregional basin, and the first seven digits (columns 1-7) identify the local basin. Below are examples of the hierarchical drainage basin numbers. Basin Numbers: 4 = Major drainage basin number, MBAS_NO (column 1) 43 = Regional drainage basin number, RBAS_NO (columns 1-2) 4302 = Subregional drainage basin number, SBAS_NO (columns 1-4) 4302-04 = Local drainage basin number, LBAS_NO (columns 1-7) 4302-04-1-R12 = Basin drainage identification number, BASIN_NO (columns 1-13) Stream Order (column 9): 4304-00-1 = Stream order value of 1 represents a headwater basin. 4304-00-2 = Stream order value > 1 denotes the complexity of the drainage basin morphology. Mapping Status Element (column 10): 4302-00-2- = Ending with minus sign (-) denotes detail mapping at 1:24,000 scale for entire basin. 4302-00-2+ = Ending with plus sign (+) denotes detailed mapping not performed at 1:24,000 scale for the entire drainage basin. The Stream Order value will not reflect the complexity of the drainage basin morphology. 4302-00-1* = Ending with asterisk sign (*) denotes a headwater basin containing a delineated impoundment into which a delineated drainage basin outlets. Reach-Impoundment Identifier (column11) and Number (column 12-13): 4302-00-1-L1 = The value for the Reach-Impoundment Identifier for an impounment basin is L (for lake). It is followed by the Reach-Impoundment Number (1). 4302-04-1-R12 = The value for the Reach-Impoundment Identifier for a stream reach basin is R (for reach). It is followed the Reach-Impoundment Number (12).
publication date
Polygon features depict the intersection and overlap of Connecticut Subregional drainage basins and Connecticut towns (municipalities). There is one polygon feature for each subregional drainage basin - town combination, including one for each coastal island identifying both the town the island is located in and the coastal subregional basin the island is offshore of. (Source: State of Connecticut, Department of Environmental Protection)
Internal feature number. (Source: ESRI)
Feature geometry. (Source: ESRI)
Subregional Drainage Basin Number - This number defines the Subregional drainage basin and is the first 4 digits of the 13-digit drainage basin identification number (BASIN_NO). The first digit corresponds to the Major basin number (MBAS_NO) and the first 2 digits represent the Regional basin number (RBAS_NO). All Subregional basins in the same Major and Regional basin have the same first and first 2 digits, respectively. A Subregional drainage basin number ending in "00" defines the main-stem basin for the corresponding Regional drainage basin. For example, Subregional basin 4300 is the main-stem basin for Regional basin 43. These main-stem Subregional basins are usually named after the corresponding Regional basin. (Source: State of Connecticut, Department of Environmental Protection)
| Value | Definition |
|---|---|
| 1000 | Pawcatuck River |
| 1001 | Wyassup Brook |
| 1002 | Green Fall River |
| 1003 | Ashaway River |
| 1004 | Shunock River |
| 1100 | Wood River |
| 1101 | Brushy Brook |
| 2000 | Southeast Shoreline |
| 2101 | Anguilla Brook |
| 2102 | Copps Brook |
| 2103 | Williams Brook |
| 2104 | Whitford Brook |
| 2105 | Haleys Brook |
| 2106 | Mystic River |
| 2107 | Great Brook |
| 2201 | Jordan Brook |
| 2202 | Latimer Brook |
| 2203 | Oil Mill Brook |
| 2204 | Niantic River |
| 2205 | Pattagansett River |
| 2206 | Bride Brook |
| 2207 | Fourmile River |
| 3000 | Thames River |
| 3001 | Trading Cove Brook |
| 3002 | Shewville Brook |
| 3003 | Poquetanuck Brook |
| 3004 | Oxoboxo Brook |
| 3005 | Stony Brook |
| 3006 | Hunts Brook |
| 3100 | Willimantic River |
| 3101 | Edson Brook |
| 3102 | Middle River |
| 3103 | Furnace Brook |
| 3104 | Roaring Brook |
| 3105 | Mill Brook |
| 3106 | Skungamaug River |
| 3107 | Burnap Brook |
| 3108 | Hop River |
| 3109 | Giffords Brook |
| 3110 | Tenmile River |
| 3200 | Natchaug River |
| 3201 | Bungee Brook |
| 3202 | Still River |
| 3203 | Bigelow Brook |
| 3204 | Stonehouse Brook |
| 3205 | Squaw Hollow Brook |
| 3206 | Mount Hope River |
| 3207 | Fenton River |
| 3208 | Sawmill Brook |
| 3300 | French River |
| 3301 | Mill Brook |
| 3400 | Fivemile River |
| 3401 | Rocky Brook |
| 3402 | Mary Brown Brook |
| 3403 | Cady Brook |
| 3404 | Whetstone Brook |
| 3500 | Moosup River |
| 3501 | Quanduck Brook |
| 3502 | Snake Meadow Brook |
| 3503 | Ekonk Brook |
| 3600 | Pachaug River |
| 3601 | Great Meadow Brook |
| 3602 | Mount Misery Brook |
| 3603 | Denison Brook |
| 3604 | Myron Kinney Brook |
| 3605 | Billings Brook |
| 3700 | Quinebaug River |
| 3701 | Hamilton Reservoir Brook |
| 3702 | Breakneck Brook |
| 3703 | Hatchet Brook |
| 3704 | Cohasse Brook |
| 3705 | Lebanon Brook |
| 3706 | English Neighborhood Brook |
| 3707 | Mill Brook |
| 3708 | Little River |
| 3709 | Wappoquia Brook |
| 3710 | Mashamoquet Brook |
| 3711 | Blackwell Brook |
| 3712 | Fry Brook |
| 3713 | Mill Brook |
| 3714 | Kitt Brook |
| 3715 | Cory Brook |
| 3716 | Broad Brook |
| 3717 | Choate Brook |
| 3800 | Shetucket River |
| 3801 | Indian Hollow Brook |
| 3802 | Beaver Brook |
| 3803 | Merrick Brook |
| 3804 | Beaver Brook |
| 3805 | Little River |
| 3900 | Yantic River |
| 3901 | Exeter Brook |
| 3902 | Bartlett Brook |
| 3903 | Sherman Brook |
| 3904 | Deep River |
| 3905 | Pease Brook |
| 3906 | Gardner Brook |
| 3907 | Susquetonscut Brook |
| 4000 | Connecticut River |
| 4001 | Great Brook |
| 4002 | Threemile Brook |
| 4003 | Freshwater Brook |
| 4004 | Podunk River |
| 4005 | Folly Brook |
| 4006 | Salmon Brook |
| 4007 | Hubbard Brook |
| 4008 | Cold Brook |
| 4009 | Roaring Brook |
| 4010 | Goff Brook |
| 4011 | Reservoir Brook |
| 4012 | Carr Brook |
| 4013 | Sumner Brook |
| 4014 | Higganum Creek |
| 4015 | Mill Creek |
| 4016 | Whalebone Creek |
| 4017 | Chester Creek |
| 4018 | Deep River |
| 4019 | Falls River |
| 4020 | Lieutenant River |
| 4021 | Black Hall River |
| 4100 | Stony Brook |
| 4101 | Muddy Brook |
| 4200 | Scantic River |
| 4201 | Watchaug Brook |
| 4202 | Gillettes Brook |
| 4203 | Gulf Stream |
| 4204 | Abbey Brook |
| 4205 | Buckhorn Brook |
| 4206 | Broad Brook |
| 4207 | Ketch Brook |
| 4300 | Farmington River |
| 4301 | Slocum Brook |
| 4302 | Mad River |
| 4303 | Still River |
| 4304 | Sandy Brook |
| 4305 | Morgan Brook |
| 4306 | Valley Brook |
| 4307 | Hubbard Brook |
| 4308 | East Branch Farmington River |
| 4309 | Cherry Brook |
| 4310 | Nepaug River |
| 4311 | Burlington Brook |
| 4312 | Roaring Brook |
| 4313 | Poland River |
| 4314 | Copper Mine Brook |
| 4315 | Pequabuck River |
| 4316 | Thompson Brook |
| 4317 | Nod Brook |
| 4318 | Hop Brook |
| 4319 | West Branch Salmon Brook |
| 4320 | Salmon Brook |
| 4321 | Mill Brook |
| 4400 | Park River |
| 4401 | Bass Brook |
| 4402 | Piper Brook |
| 4403 | Trout Brook |
| 4404 | North Branch Park River |
| 4500 | Hockanum River |
| 4501 | Charters Brook |
| 4502 | Marsh Brook |
| 4503 | Tankerhoosen River |
| 4504 | South Fork Hockanum River |
| 4600 | Mattabesset River |
| 4601 | Belcher Brook |
| 4602 | Willow Brook |
| 4603 | Webster Brook |
| 4604 | Sawmill Brook |
| 4605 | Allyn Brook |
| 4606 | Sawmill Brook |
| 4607 | Coginchaug River |
| 4700 | Salmon River |
| 4701 | Raymond Brook |
| 4702 | Judd Brook |
| 4703 | Meadow Brook |
| 4704 | Pine Brook |
| 4705 | Jeremy River |
| 4706 | Fawn Brook |
| 4707 | Blackledge River |
| 4708 | Dickinson Creek |
| 4709 | Pine Brook |
| 4710 | Moodus River |
| 4800 | Eightmile River |
| 4801 | Harris Brook |
| 4802 | East Branch Eightmile River |
| 4803 | Beaver Brook |
| 5000 | South Central Shoreline |
| 5101 | Oyster River |
| 5102 | Patchogue River |
| 5103 | Menunketesuck River |
| 5104 | Indian River |
| 5105 | Chatfield Hollow Brook |
| 5106 | Hammonasset River |
| 5107 | Neck River |
| 5108 | East River |
| 5109 | Sluice Creek |
| 5110 | West River |
| 5111 | Branford River |
| 5112 | Farm River |
| 5200 | Quinnipiac River |
| 5201 | Eightmile River |
| 5202 | Tenmile River |
| 5203 | Misery Brook |
| 5204 | Broad Brook |
| 5205 | Sodom Brook |
| 5206 | Harbor Brook |
| 5207 | Wharton Brook |
| 5208 | Muddy River |
| 5301 | Willow Brook |
| 5302 | Mill River |
| 5303 | Sargent River |
| 5304 | Wintergreen Brook |
| 5305 | West River |
| 5306 | Indian River |
| 5307 | Wepawaug River |
| 6000 | Housatonic River |
| 6001 | Sages Ravine Brook |
| 6002 | Schenob Brook |
| 6003 | Andrus Brook |
| 6004 | Konkapot River |
| 6005 | Factory Brook |
| 6006 | Spruce Swamp Creek |
| 6007 | Salmon Creek |
| 6008 | Mill Brook |
| 6009 | Carse Brook |
| 6010 | Furnace Brook |
| 6011 | Guinea Brook |
| 6012 | Kent Falls Brook |
| 6013 | Cobble Brook |
| 6014 | Bog Hollow Brook |
| 6015 | Macedonia Brook |
| 6016 | Womenshenuk Brook |
| 6017 | Morrissey Brook |
| 6018 | Pond Brook |
| 6019 | Deep Brook |
| 6020 | Pootatuck River |
| 6021 | Kettletown Brook |
| 6022 | Halfway River |
| 6023 | Eightmile Brook |
| 6024 | Means Brook |
| 6025 | Farmill River |
| 6026 | Pumpkin Ground Brook |
| 6100 | Blackberry River |
| 6101 | Whiting River |
| 6200 | Hollenbeck River |
| 6201 | Brown Brook |
| 6202 | Wangum Lake Brook |
| 6300 | Tenmile River |
| 6301 | Indian Lake Creek |
| 6302 | Mill Brook |
| 6303 | Webatuck Creek |
| 6304 | Deuel Hollow Brook |
| 6305 | Mill River |
| 6306 | Swamp River |
| 6400 | Lake Candlewood |
| 6401 | Sawmill Brook |
| 6402 | Ball Pond Brook |
| 6500 | West Aspetuck River |
| 6501 | Merryall Brook |
| 6502 | East Aspetuck River |
| 6600 | Still River |
| 6601 | Miry Brook |
| 6602 | Boggs Pond Brook |
| 6603 | Padanaram Brook |
| 6604 | Sympaug Brook |
| 6605 | East Swamp Brook |
| 6606 | Limekiln Brook |
| 6700 | Shepaug River |
| 6701 | Marshepaug River |
| 6702 | West Branch Shepaug River |
| 6703 | West Branch Bantam River |
| 6704 | Butternut Brook |
| 6705 | Bantam River |
| 6706 | Jacks Brook |
| 6800 | Pomperaug River |
| 6801 | East Spring Brook |
| 6802 | Nonewaug River |
| 6803 | Sprain Brook |
| 6804 | Weekeepeemee River |
| 6805 | Hesseky Brook |
| 6806 | Transylvania Brook |
| 6900 | Naugatuck River |
| 6901 | Hall Meadow Brook |
| 6902 | Hart Brook |
| 6903 | Nickel Mine Brook |
| 6904 | West Branch Naugatuck River |
| 6905 | East Branch Naugatuck River |
| 6906 | Spruce Brook |
| 6907 | Rock Brook |
| 6908 | Leadmine Brook |
| 6909 | Northfield Brook |
| 6910 | Branch Brook |
| 6911 | Hancock Brook |
| 6912 | Steele Brook |
| 6913 | Beaver Pond Brook |
| 6914 | Mad River |
| 6915 | Fulling Mill Brook |
| 6916 | Hop Brook |
| 6917 | Long Meadow Pond Brook |
| 6918 | Beacon Hill Brook |
| 6919 | Bladens River |
| 6920 | Little River |
| 7000 | Southwest Shoreline |
| 7101 | Lewis Gut |
| 7102 | Bruce Brook |
| 7103 | Yellow Mill Channel |
| 7104 | Booth Hill Brook |
| 7105 | Pequonnock River |
| 7106 | Ash Creek |
| 7107 | Cricker Brook |
| 7108 | Mill River |
| 7109 | Sasco Brook |
| 7200 | Saugatuck River |
| 7201 | Little River |
| 7202 | Aspetuck River |
| 7203 | West Branch Saugatuck River |
| 7300 | Norwalk River |
| 7301 | Comstock Brook |
| 7302 | Silvermine River |
| 7401 | Fivemile River |
| 7402 | Darien River |
| 7403 | Noroton River |
| 7404 | Mill River |
| 7405 | Rippowam River |
| 7406 | East Branch Mianus River |
| 7407 | Mianus River |
| 7408 | Greenwich Creek |
| 7409 | Horseneck Brook |
| 7410 | East Branch Byram River |
| 7411 | Byram River |
| 7412 | Blind Brook |
| 8000 | Hudson River |
| 8100 | Croton River |
| 8101 | Quaker Brook |
| 8102 | Corner Pond Brook |
| 8103 | East Branch Croton River |
| 8104 | Titicus River |
| 8105 | Waccabuc River |
Subregional Drainage Basin Name - Text values that correspond to numeric SBAS_NO attribute values. SUBREGION is the English language equivalent of (decodes) the SBAS_NO field. (Source: State of Connecticut, Department of Environmental Protection)
Regional Drainage Basin Number - This number defines the Regional drainage basin and is the first 2 digits of the 13-digit drainage basin identification number (BASIN_NO). The first digit corresponds to the Major basin number (MBAS_NO). All Regional basins in the same Major basin have the same first digit. A Regional drainage basin number ending in "0" defines the greater main-stem basin for the corresponding Major drainage basin. For example, Regional basin 40 is the main-stem basin for Major basin 4. These main-stem Regional basins are usually named after the corresponding Major basin. (Source: State of Connecticut, Department of Environmental Protection)
| Value | Definition |
|---|---|
| 10 | Pawcatuck Main Stem |
| 11 | Wood |
| 20 | Southeast Shoreline |
| 21 | Southeast Eastern Complex |
| 22 | Southeast Western Complex |
| 30 | Thames Main Stem |
| 31 | Willimantic |
| 32 | Natchaug |
| 33 | French |
| 34 | Fivemile |
| 35 | Moosup |
| 36 | Pachaug |
| 37 | Quinebaug |
| 38 | Shetucket |
| 39 | Yantic |
| 40 | Connecticut Main Stem |
| 41 | Stony Brook |
| 42 | Scantic |
| 43 | Farmington |
| 44 | Park |
| 45 | Hockanum |
| 46 | Mattabesset |
| 47 | Salmon |
| 48 | Eightmile |
| 50 | South Central Shoreline |
| 51 | South Central Eastern Complex |
| 52 | Quinnipiac |
| 53 | South Central Western Complex |
| 60 | Housatonic Main Stem |
| 61 | Blackberry |
| 62 | Hollenbeck |
| 63 | Tenmile |
| 64 | Candlewood |
| 65 | Aspetuck |
| 66 | Still |
| 67 | Shepaug |
| 68 | Pomperaug |
| 69 | Naugatuck |
| 70 | Southwest Shoreline |
| 71 | Southwest Eastern |
| 72 | Saugatuck |
| 73 | Norwalk |
| 74 | Southwest Western Complex |
| 80 | Hudson Main Stem |
| 81 | Croton |
Regional Drainage Basin Name - Text values that correspond to numeric RBAS_NO attribute values. REGIONAL is the English language equivalent of (decodes) the RBAS_NO field. (Source: State of Connecticut, Department of Environmental Protection)
Major Drainage Basin Number - This number defines the major drainage basin and is the first digit of the 13-digit drainage basin identification number (BASIN_NO). There are 8 Major basins. (Source: State of Connecticut, Department of Environmental Protection)
| Value | Definition |
|---|---|
| 1 | Pawcatuck |
| 2 | Southeast Coast |
| 3 | Thames |
| 4 | Connecticut |
| 5 | South Central Coast |
| 6 | Housatonic |
| 7 | Southwest Coast |
| 8 | Hudson |
Major Drainage Basin Name - Text values that correspond to numeric MBAS_NO attribute values. MAJOR is the English language equivalent of (decodes) the MBAS_NO field. (Source: State of Connecticut, Department of Environmental Protection)
Town Number - ID number for the Connecticut Town (municipality), based on the Town Codes issued by the State of Connecticut, Office of the State Controller, which range from 1 to 169. (Source: State of Connecticut, Office of the State Controller)
Town Name - Text values that correspond to numeric TOWN_NO attribute values. TOWN is the English language equivalent of (decodes) the TOWN_NO field. (Source: State of Connecticut, Office of the State Controller)
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)
Calculated area of polygon feature in square miles. Note, AREA_SQMI 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)
Information encoded for drainage basin polygon features generally includes drainage basin number and name, town number and name, and feature size. The SBAS_NO uniquely identifes subreginal drainage basins and uniquely identifies each polygon feature. It represents the first 4 digits of the 13 digit BASIN_NO. The drainage basin numbering system is hierarchical. Use the MBAS_NO and RBAS_NO attributes to identify the major and regional drainage basin for each subregional drainage basin feature. The TOWN_NO identifies the Connecticut Town the basin feature is located in. Typically basins are located in more than one town and a town will include more than one basin so there is a polygon feature for each subregional basin - town occurrence. Use the AREA_SQMI and ACREAGE attributes to determine drainage basin - town polygon feature size. These values reflect the area of the respective polygon feature. They do not reflect the cumulative (upstream) drainage area for each basin. Note, ACREAGE and AREA_SQMI values are not automatically updated after modifying feature geometry (shape). These values must be recalculated after features are edited, simplified, generalized, clipped, dissolved, etc.
Basin Numbers: 4 = Major drainage basin number, MBAS_NO (column 1) 43 = Regional drainage basin number, RBAS_NO (columns 1-2) 4302 = Subregional drainage basin number, SBAS_NO (columns 1-4) 4302-04 = Local drainage basin number, LBAS_NO (columns 1-7) 4302-04-1-R12 = Basin drainage identification number, BASIN_NO (columns 1-13) Stream Order (column 9): 4304-00-1 = Stream order value of 1 represents a headwater basin. 4304-00-2 = Stream order value > 1 denotes the complexity of the drainage basin morphology. Mapping Status Element (column 10): 4302-00-2- = Ending with minus sign (-) denotes detail mapping at 1:24,000 scale for entire basin. 4302-00-2+ = Ending with plus sign (+) denotes detailed mapping not performed at 1:24,000 scale for the entire drainage basin. The Stream Order value will not reflect the complexity of the drainage basin morphology. 4302-00-1* = Ending with asterisk sign (*) denotes a headwater basin containing a delineated impoundment into which a delineated drainage basin outlets. Reach-Impoundment Identifier (column11) and Number (column 12-13): 4302-00-1-L1 = The value for the Reach-Impoundment Identifier for an impounment basin is L (for lake). It is followed by the Reach-Impoundment Number (1). 4302-04-1-R12 = The value for the Reach-Impoundment Identifier for a stream reach basin is R (for reach). It is followed the Reach-Impoundment Number (12).
Connecticut Town numbers, based on the Town Codes issued by the State of Connecticut, range from 1 to 169 in the following order: Andover (1), Ansonia (2), Ashford (3), Avon (4), Barkhamsted (5), Beacon Falls (6), Berlin (7), Bethany (8), Bethel (9), Bethlehem (10), Bloomfield (11), Bolton (12), Bozrah (13), Branford (14), Bridgeport (15), Bridgewater (16), Bristol (17), Brookfield (18), Brooklyn (19), Burlington (20), Canaan (21), Canterbury (22), Canton (23), Chaplin (24), Cheshire (25), Chester (26), Clinton (27), Colchester (28), Colebrook (29), Columbia (30), Cornwall (31), Coventry (32), Cromwell (33), Danbury (34), Darien (35), Deep River (36), Derby (37), Durham (38), Eastford (39), East Granby (40), East Haddam (41), East Hampton (42), East Hartford (43), East Haven (44), East Lyme (45), Easton (46), East Windsor (47), Ellington (48), Enfield (49), Essex (50), Fairfield (51), Farmington (52), Franklin (53), Glastonbury (54), Goshen (55), Granby (56), Greenwich (57), Griswold (58), Groton (59), Guilford (60), Haddam (61), Hamden (62), Hampton (63), Hartford (64), Hartland (65), Harwinton (66), Hebron (67), Kent (68), Killingly (69), Killingworth (70), Lebanon (71), Ledyard (72), Lisbon (73), Litchfield (74), Lyme (75), Madison (76), Manchester (77), Mansfield (78), Marlborough (79), Meriden (80), Middlebury (81), Middlefield (82), Middletown (83), Milford (84), Monroe (85), Montville (86), Morris (87), Naugatuck (88), New Britain (89), New Canaan (90), New Fairfield (91), New Hartford (92), New Haven (93), Newington (94), New London (95), New Milford (96), Newtown (97), Norfolk (98), North Branford (99), North Canaan (100), North Haven (101), North Stonington (102), Norwalk (103), Norwich (104), Old Lyme (105), Old Saybrook (106), Orange (107), Oxford (108), Plainfield (109), Plainville (110), Plymouth (111), Pomfret (112), Portland (113), Preston (114), Prospect (115), Putnam (116), Redding (117), Ridgefield (118), Rocky Hill (119), Roxbury (120), Salem (121), Salisbury (122), Scotland (123), Seymour (124), Sharon (125), Shelton (126), Sherman (127), Simsbury (128), Somers (129), Southbury (130), Southington (131), South Windsor (132), Sprague (133), Stafford (134), Stamford (135), Sterling (136), Stonington (137), Stratford (138), Suffield (139), Thomaston (140), Thompson (141), Tolland (142), Torrington (143), Trumbull (144), Union (145), Vernon (146), Voluntown (147), Wallingford (148), Warren (149), Washington (150), Waterbury (151), Waterford (152), Watertown (153), Westbrook (154), West Hartford (155), West Haven (156), Weston (157), Westport (158), Wethersfield (159), Willington (160), Wilton (161), Winchester (162), Windham (163), Windsor (164), Windsor Locks (165), Wolcott (166), Woodbridge (167), Woodbury (168), and Woodstock (169).
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.
79 Elm Street
These data are used for geoprocessing and analysis purposes. They function as a two-way index of basins and towns, identifying the towns each subregional drainage basin is located in as well as identifying the subregional drainage basins located in each town. A town can be analyzed relative to basins, or a basin can be analyzed relative to towns. A polygon feature exists for each area where a subregional basin overlaps a town. If a basin is located in two different parts of town, a polygon feature will exist for each. Polygon feature size is available in square miles or acres so basin occurrence as a percent of town area can be determined. These data are intended for analysis with other digital data compiled at 1:24,000 scale or greater.
Basins compiled on 1:24,000-scale 7.5 minute USGS quadrangle area mylar overlays.
Connecticut Drainage Basins is in ArcInfo Coverage format having both polygon and line features. The name of the ArcInfo Coverage is BASIN.
Connecticut Subregional Drainage Basins is in ArcInfo Coverage format having both polygon and line features. The name of the ArcInfo Coverage is SBASIN. These polygon and line feature data were subsequently converted to geodatabase feature format and named SUBREGIONAL_BASIN_POLY and SUBREGIONAL_BASIN_LINE, respectively.
A polygon feature-based layer that depicts the geographic area for the State of Connecticut as one polygon feature. Connecticut State Poly is in Geodatabase Feature Class format.
Connecticut Subregional Drainage Basins for Clipping originated from the Connecticut Subregional Drainage Basins Polygon feature class (SUBREGIONAL_BASIN_POLY)
A polygon feature-based layer that defines the geographic areas for the State of Connecticut and its counties and towns (municipalities) as depicted on the U.S. Geological Survey (USGS) 7.5 minute topographic quadrangle maps for the State of Connecticut. This layer only includes information for Connecticut. Connecticut_Town_Poly is in Geodatabase Feature Class format.
Feature digitizing and attribution (digitizing tablet method) - Using ESRI ArcInfo software, basin boundary line features were digitized by registering the individual compilation sheets to the digitizing tablet and using the crosshairs of the digitizer's mouse to manually capture the geometry (location) of features drafted on the map. The corners of the USGS 7.5 minute topographic quadrangle maps are used as registration points and are depicted on the source map. The source map was registered to the digitizing tablet by digitizing (entering) the locations of four quadrangle corner registration points shown on the map. ArcInfo software compared the values of the digitized coordinates with the actual (true) values for the quadrangle corner (tic) features. The Root Mean Square (RMS) error generated by the ArcInfo software indicated the amount of error involved in transforming coordinates from the registered map to the digital layer. RMS errors higher than 0.004 were not acceptable and required re-registering the source map by digitizing the tic locations again. With a correct registration, basins boundaries features were manually digitized off the source map. Where necessary, additional minor corrections (edits) to feature geometry were manually digitized on the screen (heads-up digitizing) at display scales greater than 1:24,000. Feature location and attribute accuracy was visually checked and inspected by symbolizing and labeling features according to attribute value on the computer screen and on hard copy paper maps, and comparing this information to the orginal source data. These check plot maps were printed at the same scale as the source maps in order to visually inspect digitizing quality and the assignment of attribute values. Individual quadrangle level basin boundary coverages were appended and edgematched along quadrangle boundaries to create a statewide layer in ArcInfo Coverage format having both polygon and line features. Polygon label points were created and assigned BASIN_NO values that uniquely identified each polygon feature. Most other related polygon and line feature attributes were assigned through automated procedures based on the format and hierarchical nature of the BASIN_NO value. Four additional fields (MBAS_NO, RBAS_NO, SBAS_NO, LBAS_NO) were added and populated based on the first, first 2, first 4, and first 7 columns of the BASIN_NO attribute. The MAJOR, REGIONAL, and SUBREGION attributes store drainage basin names based on MBAS_NO, RBAS_NO, SBAS_NO values, respectively. Basin names were attributed by joining basin name lookup tables to the polygon features base on MBAS_NO, RBAS_NO, SBAS_NO key values and populating the corresponding fields. These basin names are from the Natural Drainage Basins in Connecticut map, McElroy, 1981. The AREA_SQMI (area in square miles) and ACREAGE (area in acres) field were automatically calculated for each polygon feature based on computer generated feature area in square feet. The GAZRECNO attribute was manually assigned to each basin polygon feature. For line features, the DBARC_COD attribute was populated through a combination of automated and manual processes that compared the BASIN_NO attribute value of the polygon on each side of the line. For example, if the two polygons are in different major basins (MBAS_NO on the left <> MBAS_NO on the right), then the line feature represents a Major basin drainage divide and is assigned a DBARC_COD value of 1. If the left and right polygons are in the same Major basins but in different regional basins (RBAS_NO on the left <> RBAS_NO on the right), the line feature is a Regional basin drainage divide and is assigned a DBARC_COD value of 2, and so on. DIVIDE is the English language equivalent of (decodes) the DBARC_COD attribute value and was populated by joining a lookup table to the line features instead of manually attributing these values for each line feature. AV_LEGEND and IMS_LEGEND values were also attributed through table joins.
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Create Subregional Drainage Basins - Using ArcInfo Workstation software, removed the BASIN_NO and LBAS_NO polygon feature attributes, calculated the ACREAGE and AREA_SQMI polygon attributes to zero, and dissolved polygon features on the remaining SBAS_NO, RBAS_NO, MBAS_NO, SUBREGIONAL, REGIONAL, and MAJOR attribute values to create subregional drainage basin polygon features. Using the ArcInfo Dissolve command, this step merged the smaller basin polygons into the larger subregional basin polygon features. Line features were preserved as part of the dissolve process and were merged using the ArcInfo Unsplit command afterwards. The ACREAGE and AREA_SQMI attributes were recalculated based on the new feature geometry, and ArcInfo coveage topology was re-established with the Build command.
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Subregional Drainage Basin Polygon features along the Connecticut coastline were enlarged to extend beyond the Connecticut shoreline into Long Island Sound to the boundary between the State of Connectict and New York in Long Island Sound. This feature class is designed to be used as a Clip feature class to clip other point line and polygon features to the subregional drainage basin areas. This feature class differs from the Subregional Drainage Basin Polygon feature class in that features along the Connecticut coastline were enlarged to extend beyond the Connecticut shoreline to the boundary between the State of Connectict and New York in Long Island Sound. These modifications apply to the coastal subregional basins 2000, 5000, and 7000 where the basin boundary coresponding to the Connecticut shoreline was replaced with the CT-NY state boundary in Long Island Sounce. These basin areas were enlarged to ensure Clip input features located along and near both sides of the shoreline are included in the Clip output feature class and associated with a subregional coastal basin (e.g. 2000, 5000, or 7000). Input features that should be in these coastal basins may not be in the resulting Clip output feature class unless the Connecticut Subregional Drainage Basins for Clipping is used as the Clip feature class. Using the unmodified, original Connecticut Subregional Drainage Basin Polygon feature class as the Clip feature class may produce different results for basins 2000, 5000, and 7000. The data source for the CT-NY state boundary is the Connecticut State Poly feature class. Both data sources used - Subregional Drainage Basins and Connecticut State Poly - have a 1:24,000-scale source map scale.
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Create Subregional Drainage Basin Town Intersect - Using a copy of the Connecticut Town Poly feature class, deleted all polygon attributes with the exception of town number (TOWN_NO) and town name (TOWN). Applied the Intersect geoprocessing command to overlay the modified town feature class with Subregional Drainage Basins for Clipping to create Connecticut Subregional Basin Town Intersect feature class, which only included polygon features where the two input feature classes intersected and overlapped each other. The ACREAGE and AREA_SQMI attributes in Connecticut Subregional Basin Town Intersect were recalculated based on the new feature geometry. The total geographic area covered by all polygon features is 4,967.56 square miles.
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The primary data source for basin information in the Connecticut Subregional Drainage Basin Town Intersect feature class is the Connecticut Drainage Basins layer. The Connecticut Drainage Basins layer retains the feature types and information identified on the 1:24,000-scale compilation sheets for the Natural Drainage Basins in Connecticut map, McElroy, 1981. All attributes have valid values. Values are within defined domains. There are no duplicate LBASIN_NO values except where expected (see definition of LBASIN_NO attribute). The SBASIN_NO is derived from the first 4-digits of BASIN_NO so the accuracy of the SBASIN_NO is dependent on that for the BASIN_NO. For polygon features, the accuracy test for the BASIN_NO attribute values was conducted by visually comparing the basin number information depicted on the source Mylar overlays with 1:24,000-scale check plots or interactive displays of the digital data on a computer graphic system. These check plot maps and computer displays labeled polygon features with BASIN_NO values and differentiated line features based on DBARC_COD values for comparison with the original source Mylars. Subsequently, four additional fields (MBAS_NO, RBAS_NO, SBAS_NO, LBAS_NO) were added and populated based on the first, first 2, first 4, and first 7 columns of the BASIN_NO attribute. The MAJOR, REGIONAL, and SUBREGION attributes store drainage basin names based on MBAS_NO, RBAS_NO, SBAS_NO values, respectively. Basin names were attributed by joining basin name lookup tables to the polygon features base on MBAS_NO, RBAS_NO, SBAS_NO key values and populating the corresponding fields. These basin names are from the Natural Drainage Basins in Connecticut map, McElroy, 1981. The AREA_SQMI (area in square miles) and ACREAGE (area in acres) field were automatically calculated for each polygon feature based on computer generated feature area in square feet. The primary data source for the town attribute information is the Connecticut Town Poly feature class. Refer to this feature class metadata for town number and name attribute accuracy report information.
The horizontal positional accuracy of this data complies with the United States National Map Accuracy Standards for 1:24,000 scale maps. According to this standard, not more than 10 percent of the locations tested are to be in error by more than 1/50 inch (40 feet) measured on the publication scale of a USGS 7.5 minute topographic quadrangle map. Drainage basin boundaries were interpolated from 10 FT elevation contours and surface water body (hydrography) information published on a set of USGS 1:24,000-scale, 7.5-minute topographic quadrangle maps that cover the State of Connecticut. Natural drainage basin boundaries were manually delineated by interpolating elevation and water body information found on topographic quadrangle maps published by the USGS between 1962 and 1984.
The data reflects the content of the data source, which is a set of 1:24,000 scale mylar sheets used to compile and publish the 1:125,000-scale Drainage Basins in Connecticut Map, McElroy, 1982. All major, regional, subregional, local and smaller basin divides were digitized from these 1:24,000-scale mylar compilation sheets. 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. Lines are single part. Line features conform to the following topological rules. 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. In general, there are no duplicate features, unresolved intersections, overshooting lines, open polygons, sliver polygons, or unlabeled (unattributed) polygons. 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 4 feet (fuzzy tolerance) and a minimum allowed overshoot length of 0 feet (dangle length).
No restrictions or legal prerequisites for using the data. 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. For example, include the following data source description when this layer is used in analysis or when printed on a map: Basins - From the Subregional Drainage Basin Town Intersect layer, compiled and published by CT DEP. Source map scale is 1:24,000.
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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) |
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| 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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