OVERVIEW

The MassGIS 1:25,000 Hydrography datalayer represents hydrographic (water-related) features, including surface water (lakes, ponds, reservoirs), wetlands, bogs, flats, rivers, streams, and others (see attributes below). The layer is a hybrid of data based on USGS Digital Line Graphs (DLGs), scanned mylar separates obtained from the USGS, and digitized hydrographic features from paper USGS 1:25,000 Topographic Quadrangle maps. This layer had previously contained features from the USGS 1:100,000 hydrography; these have been replaced with features from the scanned mylars. Available statewide, the hydrography (arc and polygon feature classes) is stored in ArcSDE as HYDRO25K_POLY and HYDRO25K_ARC. In the QUAD library the layer is named HYDRO and each coverage is named HD. The list of quadrangles and data sources are listed below.

The DLG quadrangles were converted into Arc/INFO coverages and projected into the Massachusetts State Plane Coordinate System. The long list of items (MAJOR1, MINOR1, MAJOR2, MINOR2...) was then concatenated to a more simplified coding system. For each feature MINORn was truncated to three characters and linked to the other minor codes to create MINOR_TOT. For example, a submerged (612) wetland (111) is now coded MINOR_TOT = 612111. The original MAJORn, MINORn pairs are no longer part of the attribute tables.

Quadrangles covering Nantucket and Martha’s Vineyard were completely digitized from the 1:25,000 USGS quadrangles. Though not as thoroughly coded as the 1:25,000 DLGs, the linework is all at 1:25,000.

The scanned quadrangles were automated in-house by scanning USGS mylar separates at 500 dots per inch. The resulting images were vectorized in GRID and then edited in ARCEDIT. Features missing from the blue line separate (i.e. dams or man-made shore) were digitized from the paper quadrangles.

Four quads along the Massachusetts-Connecticut border were obtained from the Connecticut DEP and projected to the Massachusetts State Plane Coordinate System.

See the status map for details on the source of each quad.

All of the digitized quadrangles were checkplotted at 1:25,000. The 1:25,000 DLG quadrangles were randomly checkplotted. Each of the quadrangles was edgematched to its neighboring quads. The scanned hydrography was compared both to the source mylars and to the paper quadrangles to ensure completeness.

For the December, 2003, update, the layer was extracted from the Quad library and dissolved into a single coverage, which was dissolved on all items after the SOURCE field was dropped. Most slivers, gaps, and other artifacts left over from the quad tiling scheme were removed. Some codes were also refined. Edits were preformed by MassGIS and Department of Environmental Protection (DEP) GIS Group staff.

The layer contains both a polygon and arc feature class. The modified DLG coding scheme is extensive and includes a wide variety of features, including ponds, cranberry bogs, impoundments, wetlands, tidal flats, dams, streams, and aqueducts. Only data from the DLGs have been coded this completely. Data from other sources have been coded to include ponds and streams and in the case of data from the scanned quads, wetlands.

Pond and Lake Identification System (PALIS) IDs are unique codes which were added to ponds and lakes by  DEP GIS in conjunction with the DEP Division of Watershed Management using identification codes developed by the Pond and Lakes Information System. For historical reasons, some wetland polygons have PALIS IDs. PALIS IDs were also given to impoundment areas along rivers and when necessary closure lines were added.

The items in the polygon attribute table are:
 

MINOR_TOT	15	15	C		Concatenated feature code
PWSID	11	11	C		DEP public water supply identification number
POLY_CODE	4	5	B		Generalized code based on MINOR_TOT simplified to these 9 codes:  0 - LAND/ISLAND/DAM/AQUEDUCT  1 - RESERVOIR (with PWSID)  2 - WETLAND, MARSH, SWAMP, BOG  3 - SUBMERGED WETLANDS  4 - CRANBERRY BOG  5 - SALT WETLANDS  6 - LAKE, POND, WIDE RIVER, IMPOUNDMENT  7 - TIDAL FLATS, SHOALS  8 - BAY, OCEAN  9 - INUNDATED AREA
PALIS_ID	6	8	I		A unique ID from the Ponds and Lakes Information System
MINOR_NUM	15	15	I		Same as MINOR_TOT, as integer (redefined item in Arc Librarian)
SYM_COMM	60	60	I		Generalized symbolization comment, useful for map legends

The items in the arc attribute table are:
 

MINOR_TOT	12	12	C		Concatenated feature code
PWSID	11	11	C		DEP public water supply identification number
ARC_CODE	4	5	B		Generalized code based on MINOR_TOT simplified to these codes:  1 - SHORELINE  2 - CLOSURE LINE  3 - APPARENT WETLAND LIMIT  4 - STREAM  5 - INTERMITTENT STREAM  6 - DITCH, CANAL  7 - AQUEDUCT  8 - DAM  9 - INTERMITTENT/INDEFINITE SHORELINE 10 - MAN-MADE SHORELINE 11 - CHANNEL IN WATER 99 - TRANSPORT ARC  0 - UNKNOWN
MINOR_NUM	12	12	I		Same as MINOR_TOT, as integer (redefined item in Arc Librarian)

The following table lists all the possible MINOR_TOT/MINOR_NUM codes for a POLYGON FEATURE. These codes have been extracted and concatenated from the USGS DLG major/minor pairs.
 

MINOR_TOT/NUM   DESCRIPTION 101 RESERVOIR 102 COVERED RESERVOIR 105 INUNDATION AREA 106 FISH HATCHERY/FARM 107 INDUST WATER IMPOUND 109 SEWAGE DISP POND 111 MARSH/WETLAND 114 CRANBERRY BOG 115 FLATS 116 BAY/ESTUARY/GULF 124 FILTRATION POND 400 RAPIDS 401 FALLS 402 GRAVEL PIT W/WATER 404 PUMPING STATION 406 DAM/WEIR 408 SPILLWAY 410 ROCK 412 STREAM 414 DITCH/CANAL 415 AQUEDUCT 416 FLUME 419 CHANNEL IN WATER 421 LAKE OR POND 422 CORAL REEF 999 LAND/ISLAND 7105 INUNDATION AREA 7111 MARSH/WETLAND 101619 RESERVOIR 101625 RESERVOIR 102111 COV RESERVOIR/MARSH 105007 INUNDATION AREA 105111 INUN AREA/MARSH

MINOR_TOT/NUM   DESCRIPTION 109421 SEWAGE POND/POND 109611 SEWAGE POND-ABAND 109619 SEWAGE POND 111007 MARSH/WETLAND 111105 MARSH/INUN AREA 111114 MARSH/CRANBERRY BOG 111608 MARSH-SALT 111612 MARSH-SUBMERGED 114007 CRANBERRY BOG 114111 CRANBERRY BOG/MARSH 115007 FLATS 115020 FLATS 115116 FLATS/BAY 115410 FLATS/ROCK 115412 FLATS/STREAM 115421 FLATS/POND 115422 FLATS/CORAL REEF 115616 FLATS-NAVIGABLE 406618 DAM-EARTHEN 410115 ROCKS/FLATS 412111 STREAM/MARSH 412115 STREAM FLATS 412612 STREAM-SUNKEN 415604 AQUEDUCT IN TUNNEL 419115 CHANNEL FLATS 419616 CHANNEL-NAVIGABLE 421007 LAKE OR POND 421101 POND/RESERVOIR 421111 POND WETLAND 421609 UNSURVEYED POND 421610 POND-INTERMITTENT 421612 POND-SUNKEN

MINOR_TOT/NUM   DESCRIPTION 421618 POND-EARTHEN 421619 LAKE OR POND 421625 LAKE OR POND 421628 LAKE OR POND 422115 CORAL REEF/FLATS 610402 INTERMIT PIT W/WATER 610421 INTERMITTENT POND 612111 SUBMERGED MARSH 619101 RESERVOIR 619412 STREAM 619421 LAKE OR POND 101111612 SUBMERGED RES MARSH 101619625 RESERVOIR 105007111 INUN AREA/MARSH 105111007 INUN AREA/MARSH 111007105 MARSH/INUN AREA 111007612 MARSH-SUBMERGED 111007625 MARSH/WETLAND 111105007 MARSH/INUN AREA 111114007 MARSH/CRANBERRY BOG 111612007 MARSH-SUBMERGED 111612421 POND MARSH-SUBMERGED 111612619 MARSH-SUBMERGED 111612625 MARSH-SUBMERGED 114007111 CRANBERRY BOG/MARSH 114111007 CRANBERRY BOG/MARSH 421111007 POND MARSH 421619625 LAKE OR POND 421625619 LAKE OR POND 619625415 AQUEDUCT 619625421 LAKE OR POND 101111612625 RES MARSH-SUBMERGED

The following table lists all the possible MINOR_NUM/MINOR_TOT codes for an ARC FEATURE. These codes have been extracted and concatenated from the USGS DLG major/minor pairs.
 

MINOR_TOT/NUM   DESCRIPTION 109 SEWAGE DISP/FILT BED 200 SHORELINE 201 MANMADE SHORELINE 202 CLOSURE LINE 203 INDEFINITE SHORELINE 204 APPARENT LIMIT 210 TRANSPORT ARC 300 SPRING 401 FALLS 405 WATER INTAKE 406 DAM/WEIR 407 CANAL LOCK 408 SPILLWAY 409 GATE 412 STREAM 414 DITCH/CANAL 415 AQUEDUCT 416 FLUME 419 CHANNEL IN WATER 422 CORAL REEF 605 RIGHT BANK 606 LEFT BANK 999 UNKNOWN OR NEAT LINE 7204 APPARENT LIMIT 9606 LEFT BANK 200009 SHORELINE 200201 MANMADE SHORELINE 200606 LEFT BANK/SHORE

MINOR_TOT/NUM   DESCRIPTION 200610 INTERMITTENT SHORE 201002 MANMADE SHORELINE 201009 MANMADE SHORELINE 201020 MANMADE SHORELINE 201605 MANMADE RIGHT BANK 201606 MANMADE LEFT BANK 202412 CLOSURE LINE/STREAM 203625 INDEFINITE SHORE 203627 INDEFINITE SHORE 204007 APPARENT LIMIT 204009 APPARENT LIMIT 406009 DAM/WEIR 406017 DAM/WEIR 406200 DAM/SHORE 406618 DAM/WEIR-EARTHEN 412007 STREAM 412009 STREAM 412020 STREAM 412202 STREAM CLOSURE LINE 412601 STREAM-UNDERGROUND 412604 STREAM-TUNNEL 412609 STREAM-UNSURVEYED 412610 STREAM-INTERMITTENT 414009 DITCH/CANAL 414017 DITCH/CANAL 414610 CANAL-INTERMITTENT 414611 CANAL-ABANDONED 415412 AQUEDUCT/STREAM

MINOR_TOT/NUM   DESCRIPTION 415601 AQUEDUCT-UNDERGROUND 415604 AQUEDUCT-TUNNEL 415605 AQUEDUCT RIGHT BANK 415611 AQUEDUCT-ABANDONED 415612 AQUEDUCT-SUBMERGED 601412 UNDERGROUND STREAM 605009 RIGHT BANK 605201 RIGHT BANK-MANMADE 606009 LEFT BANK 606201 LEFT BANK-MANMADE 610200 INTERMITTENT SHORE 610412 INTERMITTENT STREAM 610414 INTERMITTENT CANAL 610421 INTERMITTENT POND 200618406 SHORE/EARTHEN DAM 201009020 MANMADE SHORE 201020002 MANMADE SHORE 201020605 MANMADE RIGHT BANK 201605020 MANMADE RIGHT BANK 201606009 MANMADE LEFT BANK 201606020 MANMADE LEFT BANK 202412617 CLOS LINE/STR UNDERP 406009017 DAM/WEIR 406618017 DAM-EARTHEN 406618200 DAM-EARTHEN/SHORE 412610009 STREAM-INTERMITTENT 412610202 INT STREAM CLOSURE 412610617 INT STRM UNDERPASS

Quadrangles and the Primary Source of 1:25,000 Hydrography  (QUAD# - SOURCE)

1 - DLG 2 - SCN 3 - SCN 4 - DLG 5 - DLG 6 - DLG 7 - DLG 8 - SCN 9 - SCN 10 - DLG 11 - SCN 12 - SCN 13 - SCN 14 - SCN 15 - SCN 16 - DLG 17 - SCN 18 - SCN 19 - SCN 20 - SCN 21 - SCN 22 - DLG 23 - SCN 24 - SCN 25 - SCN 26 - SCN

27 - SCN 28 - DLG 29 - SCN 30 - SCN 31 - SCN 32 - SCN 33 - SCN 34 - DLG 35 - SCN 36 - SCN 37 - SCN 38 - SCN 39 - SCN 40 - CNR 41 - SCN 42 - SCN 43 - SCN 44 - SCN 45 - SCN 46 - CNR 47 - DLG 48 - SCN 49 - SCN 50 - SCN 51 - SCN 52 - CNR

53 - DLG 54 - SCN 55 - SCN 56 - SCN 57 - SCN 58 - CNR 59 - DLG 60 - SCN 61 - SCN 62 - SCN 63 - SCN 64 - DLG 65 - DLG 66 - SCN 67 - SCN 68 - SCN 69 - SCN 70 - DLG 71 - DLG 72 - DLG 73 - DLG 74 - DLG 75 - DLG 76 - DLG 77 - DLG 78 - DLG

79 - DLG 80 - DLG 81 - DLG 82 - DLG 83 - DLG 84 - DLG 85 - DLG 86 - DLG 87 - DLG 88 - SCN 89 - DLG 90 - DLG 91 - DLG 92 - DLG 93 - DLG 94 - SCN 95 - DLG 96 - DLG 97 - SCN 98 - SCN 99 - SCN 100 - SCN 101 - SCN 102 - DLG 103 - DLG 104 - SCN

105 - SCN 106 - SCN 107 - SCN 108 - SCN 109 - DLG 110 - DLG 111 - DLG 112 - DLG 113 - DLG 114 - SCN 115 - SCN 116 - SCN 117 - SCN 118 - SCN 119 - DLG 120 - DLG 121 - DLG 121-S - DLG 122 - DLG 123 - DLG 124 - DLG 125 - SCN 126 - SCN 127 - SCN 128 - SCN 129 - SCN

130 - DLG 131 - DLG 132 - DLG 132-S - DLG 133 - DLG 134 - DLG 135 - DLG 136 - DLG 137 - DLG 138 - DLG 139 - DLG 140 - DLG 141 - SCN 142 - SCN 143 - SCN 144 - DLG 145 - DIG 146 - DLG 147 - DLG 148 - DLG 149 - DLG 150 - DLG 151 - DLG 152 - DLG 153 - SCN 154 - SCN

155 - SCN 156 - DLG 157 - DIG 158 - DIG 158-S - DIG 159-E - DLG 159-W - DLG 160 - DLG 161 - DLG 161-E - DLG 162 - DLG 163 - DLG 164 - DLG 165 - DLG 166 - DIG 167 - DIG 168-E - DLG 168-W - DLG 169 - DLG 170 - DLG 171 - DLG 172 - DLG 173 - DIG 173-E - DIG 173-S - DIG 173-SE - DIG

174 - DLG 174-N - DLG 175 - DLG 176 - DLG 176-S - DLG 177 - DIG 178 - DLG 179 - DLG 179-N - DLG 180 - DIG 180-S - DIG 181 - DLG 182 - DLG 182-E - DLG 183 - DLG 184 - DLG 184-N - DLG 185 - DLG 186 - DLG 186-W - DLG 187 - DIG 187-E - DIG 188 - DIG 188-E - DIG 188-S - DIG 188-SE - DIG 189 - DLG

Source is for all or most features in the quad. Some features may have been modifed by on-screen digitizing.

View Hydrography Status Map

Note that theese hydrography layers do not have feature names (e.g., "Quabbin Reservoir" or "Connecticut River") as attributes. To label the features in these layers, use the annotation in the HYDRO subclass of the Geographic Place Names layer.

MassGIS and DEP GIS Group maintain the 1:25,000 hydrography layers.

The CLASS item relating to DEP Surface Water Supply Protection Zones was dropped in June of 2003. All streams and ponds within DEP Zone C’s are considered to be class A. In the December, 2003, update, the SOURCE item was dropped from the polygon attribute table. In February, 2004 the layers underwent some minor coding and feature updates in the southeast and on Cape Cod. In October, 2004 a few attribute codes were changed and a few streams were added in the Cohasset area to accommodate surface water protection layer updates.

In February, 2005, the attributes of the HYDRO25K_ARC layer were modified to set ARC_CODE = 9 where ARC_CODE was 1 and MINOR_NUM = 203. The affected watersheds are Cape Cod, Chicopee, Concord, French, Millers, Quinebaug and Ten Mile.

For other hydrographic features, also see the DEP Wetlands (1:12,000), Hydrography (1:100,000) and Major Ponds and Major Streams layers.

Last Updated 2/10/2005
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