The HUC4 Codes
4-digit Hydrological Unit Codes represent the aggregation of watersheds known as hydrologic subregions.


Sequential List


0101='ST. JOHN'
0102='PENOBSCOT'
0103='KENNEBEC'
0104='ANDROSCOGGIN'
0105='MAINE COASTAL'
0106='SACO'
0107='MERRIMACK'
0108='CONNECTICUT'
0109='MASSACHUSETTS-RHODE ISLAND COASTAL'
0110='CONNECTICUT COASTAL'
0111='ST. FRANCOIS'
0201='RICHELIEU'
0202='UPPER HUDSON'
0203='LOWER HUDSON-LONG ISLAND'
0204='DELAWARE'
0205='SUSQUEHANNA'
0206='UPPER CHESAPEAKE'
0207='POTOMAC'
0208='LOWER CHESAPEAKE'
0301='CHOWAN-ROANOKE'
0302='NEUSE-PAMLICO'
0303='CAPE FEAR'
0304='PEE DEE'
0305='EDISTO-SANTEE'
0306='OGEECHEE-SAVANNAH'
0307='ALTAMAHA-ST. MARYS'
0308='ST. JOHNS'
0309='SOUTHERN FLORIDA'
0310='PEACE-TAMPA BAY'
0311='SUWANNEE'
0312='OCHLOCKONEE'
0313='APALACHICOLA'
0314='CHOCTAWHATCHEE-ESCAMBIA'
0315='ALABAMA'
0316='MOBILE-TOMBIGBEE'
0317='PASCAGOULA'
0318='PEARL'
0401='WESTERN LAKE SUPERIOR'
0402='SOUTHERN LAKE SUPERIOR-LAKE SUPERIOR'
0403='NORTHWESTERN LAKE MICHIGAN'
0404='SOUTHWESTERN LAKE MICHIGAN'
0405='SOUTHEASTERN LAKE MICHIGAN'
0406='NORTHEASTERN LAKE MICHIGAN-LAKE MICHIGAN'
0407='NORTHWESTERN LAKE HURON'
0408='SOUTHWESTERN LAKE HURON-LAKE HURON'
0409='ST. CLAIR-DETROIT'
0410='WESTERN LAKE ERIE'
0411='SOUTHERN LAKE ERIE'
0412='EASTERN LAKE ERIE-LAKE ERIE'
0413='SOUTHWESTERN LAKE ONTARIO'
0414='SOUTHEASTERN LAKE ONTARIO'
0415='NORTHEASTERN LAKE ONTARIO-LAKE ONTARIO-ST. LAWRENCE'
0501='ALLEGHENY'
0502='MONONGAHELA'
0503='UPPER OHIO'
0504='MUSKINGUM'
0505='KANAWHA'
0506='SCIOTO'
0507='BIG SANDY-GUYANDOTTE'
0508='GREAT MIAMI'
0509='MIDDLE OHIO'
0510='KENTUCKY-LICKING'
0511='GREEN'
0512='WABASH'
0513='CUMBERLAND'
0514='LOWER OHIO'
0601='UPPER TENNESSEE'
0602='MIDDLE TENNESSEE-HIWASSEE'
0603='MIDDLE TENNESSEE-ELK'
0604='LOWER TENNESSEE'
0701='MISSISSIPPI HEADWATERS'
0702='MINNESOTA'
0703='ST. CROIX'
0704='UPPER MISSISSIPPI-BLACK-ROOT'
0705='CHIPPEWA'
0706='UPPER MISSISSIPPI-MAQUOKETA-PLUM'
0707='WISCONSIN'
0708='UPPER MISSISSIPPI-IOWA-SKUNK-WAPSIPINICON'
0709='ROCK'
0710='DES MOINES'
0711='UPPER MISSISSIPPI-SALT'
0712='UPPER ILLINOIS'
0713='LOWER ILLINOIS'
0714='UPPER MISSISSIPPI-KASKASKIA-MERAMEC'
0801='LOWER MISSISSIPPI-HATCHIE'
0802='LOWER MISSISSIPPI-ST. FRANCIS'
0803='LOWER MISSISSIPPI-YAZOO'
0804='LOWER RED-OUACHITA'
0805='BOEUF-TENSAS'
0806='LOWER MISSISSIPPI-BIG BLACK'
0807='LOWER MISSISSIPPI-LAKE MAUREPAS'
0808='LOUISIANA COASTAL'
0809='LOWER MISSISSIPPI'
0901='SOURIS'
0902='RED'
0903='RAINY'
1001='SASKATCHEWAN'
1002='MISSOURI HEADWATERS'
1003='MISSOURI-MARIAS'
1004='MISSOURI-MUSSELSHELL'
1005='MILK'
1006='MISSOURI-POPLAR'
1007='UPPER YELLOWSTONE'
1008='BIG HORN'
1009='POWDER-TONGUE'
1010='LOWER YELLOWSTONE'
1011='MISSOURI-LITTLE MISSOURI'
1012='CHEYENNE'
1013='MISSOURI-OAHE'
1014='MISSOURI-WHITE'
1015='NIOBRARA'
1016='JAMES'
1017='MISSOURI-BIG SIOUX'
1018='NORTH PLATTE'
1019='SOUTH PLATTE'
1020='PLATTE'
1021='LOUP'
1022='ELKHORN'
1023='MISSOURI-LITTLE SIOUX'
1024='MISSOURI-NISHNABOTNA'
1025='REPUBLICAN'
1026='SMOKY HILL'
1027='KANSAS'
1028='CHARITON-GRAND'
1029='GASCONADE-OSAGE'
1030='LOWER MISSOURI'
1101='UPPER WHITE'
1102='UPPER ARKANSAS'
1103='MIDDLE ARKANSAS'
1104='UPPER CIMARRON'
1105='LOWER CIMARRON'
1106='ARKANSAS-KEYSTONE'
1107='NEOSHO-VERDIGRIS'
1108='UPPER CANADIAN'
1109='LOWER CANADIAN'
1110='NORTH CANADIAN'
1111='LOWER ARKANSAS'
1112='RED HEADWATERS'
1113='RED-WASHITA'
1114='RED-SULPHUR'
1201='SABINE'
1202='NECHES'
1203='TRINITY'
1204='GALVESTON BAY-SAN JACINTO'
1205='BRAZOS HEADWATERS'
1206='MIDDLE BRAZOS'
1207='LOWER BRAZOS'
1208='UPPER COLORADO'
1209='LOWER COLORADO-SAN BERNARD COASTAL'
1210='CENTRAL TEXAS COASTAL'
1211='NUECES-SOUTHWESTERN TEXAS COASTAL'
1301='RIO GRANDE HEADWATERS'
1302='RIO GRANDE-ELEPHANT BUTTE'
1303='RIO GRANDE-MIMBRES'
1304='RIO GRANDE-AMISTAD'
1305='RIO GRANDE CLOSED BASINS'
1306='UPPER PECOS'
1307='LOWER PECOS'
1308='RIO GRANDE-FALCON'
1309='LOWER RIO GRANDE'
1401='COLORADO HEADWATERS'
1402='GUNNISON'
1403='UPPER COLORADO-DOLORES'
1404='GREAT DIVIDE-UPPER GREEN'
1405='WHITE-YAMPA'
1406='LOWER GREEN'
1407='UPPER COLORADO-DIRTY DEVIL'
1408='SAN JUAN'
1501='LOWER COLORADO-LAKE MEAD'
1502='LITTLE COLORADO'
1503='LOWER COLORADO'
1504='UPPER GILA'
1505='MIDDLE GILA'
1506='SALT'
1507='LOWER GILA'
1508='SONORA'
1601='BEAR'
1602='GREAT SALT LAKE'
1603='ESCALANTE DESERT-SEVIER LAKE'
1604='BLACK ROCK DESERT-HUMBOLDT'
1605='CENTRAL LAHONTAN'
1606='CENTRAL NEVADA DESERT BASINS'
1701='KOOTENAI-PEND OREILLE-SPOKANE'
1702='UPPER COLUMBIA'
1703='YAKIMA'
1704='UPPER SNAKE'
1705='MIDDLE SNAKE'
1706='LOWER SNAKE'
1707='MIDDLE COLUMBIA'
1708='LOWER COLUMBIA'
1709='WILLAMETTE'
1710='OREGON-WASHINGTON COASTAL'
1711='PUGET SOUND'
1712='OREGON CLOSED BASINS'
1801='KLAMATH-NORTHERN CALIFORNIA COASTAL'
1802='SACRAMENTO'
1803='TULARE-BUENA VISTA LAKES'
1804='SAN JOAQUIN'
1805='SAN FRANCISCO BAY'
1806='CENTRAL CALIFORNIA COASTAL'
1807='SOUTHERN CALIFORNIA COASTAL'
1808='NORTH LAHONTAN'
1809='NORTHERN MOJAVE-MONO LAKE'
1810='SOUTHERN MOJAVE-SALTON SEA'
1901='ARCTIC SLOPE'
1902='NORTHWEST ALASKA'
1903='YUKON'
1904='SOUTHWEST ALASKA'
1905='SOUTH CENTRAL ALASKA'
1906='SOUTHEAST ALASKA'
2001='HAWAII'
2002='MAUI'
2003='KAHOOLAWE'
2004='LANAI'
2005='MOLOKAI'
2006='OAHU'
2007='KAUAI'
2008='NIIHAU'
2009='NORTHWESTERN HAWAIIAN ISLANDS'
2101='PUERTO RICO'
2102='VIRGIN ISLANDS'
2103='CARIBBEAN OUTLYING AREAS'


Last Update: 02-04-97