List of hydrological units in the United States

This list of hydrological entities in the United States identifies the hydrological regions that the state territory of the United States is divided into. These 21 regions consist of 222 sub-regions. They correspond to 352 so-called accounting units and are divided into 2150 cataloging units at the lowest level . These subdivisions by body of water are made provided that the area in question covers a size of approximately 700 square miles .

In this system, each unit is defined by an eight-digit number code, with two digits making the assignment on the respective level. If the identification numbers of a subordinate unit are 00 , this is identical to the higher-level unit.

• 01. New England region

  All waters to the Bay of Fundy , to the Atlantic Ocean between and including the states of Maine and Connecticut, in the Long Island Sound north of the state border between New York and Connecticut as well as the part of the catchment area of ​​the Rivière Saint-François which is part of the United States

• 02. Mid-Atlantic Region

  All waters to the Atlantic Ocean between and including the states of New York and Virginia, to Long Island Sound south of the state border between New York and Connecticut as well as the part of the catchment area of ​​the Rivière Richelieu which is allotted to the United States

• 03. South Atlantic Gulf

  All waters to the Atlantic Ocean between and including the states of Virginia and Florida, to the Gulf of Mexico between and including the states of Florida and Louisiana, and waters to the adjacent marine waters in this area

• 04. Great Lakes Region

  All waters in the system of the Great Lakes and including the surface of these lakes, their bays and islands within the national territory of the United States and to the Saint Lawrence River above the catchment area of ​​the Riviere Richelieu

• 05. Ohio Region

  The Ohio River basin excluding the Tennessee River basin

• 06. Tennessee region

  Tennessee River basin

• 07. Upper Mississippi Region

  Catchment area of ​​the Mississippi River above the mouth of the Ohio River without the catchment area of ​​the Missouri River

• 08. Lower Mississippi Region

  Catchment area of ​​the Mississippi River below the mouth of the Ohio River without the catchment areas of Arkansas River , Red River and White River above the points of the greatest backflow effects of the Mississippi River on these catchment areas as well as the waters flowing into the Gulf of Mexico between the catchment areas of Pearl River and Sabine River with Sabine Lake

• 09. Souris-Red-Rainy Region

  The catchment area of ​​the Lake of the Woods as well as the catchment areas draining via Rainy River , Red River of the North and Souris River into Lake Winnipeg or Hudson Bay

• 10. Missouri Region

  Catchment areas of the Missouri and Saskatchewan rivers and several smaller closed catchments

• 11. Arkansas-White-Red Region

  The Arkansas River, White River, and Red River basins above the points of greatest backflow from the Mississippi River

• 12. Texas Gulf Region

  Waters to the Sabine Pass and the Gulf of Mexico between Sabine Pass and the catchment area of ​​the Rio Grande

• 13. Rio Grande Region

  Catchment area of ​​the Rio Grande within the United States as well as the San Luis Valley, the North Plains, the Plains of San Agustin, the catchment area of ​​the Mimbres River , Estancia, Jornada del Muerto, the Tularosa Valley, the catchment area of ​​the Salt River and other drainage basins

• 14. Upper Colorado Region

  Catchment area of ​​the Colorado River above one mile below the mouth of the Paria River (Lee Ferry Compact Point) and other bodies of water without drainage within the Great Divide Basin

• 15. Lower Colorado Region

  Catchment area of ​​the Colorado River below the Lee Ferry Compact Point, waters to the Gulf of California as well as the Animas Valley, Willcox Playa and other smaller catchment areas without drainage

• 16. Great Basin Region

  Waters to the Great Basin within the states of Utah and Nevada

• 17. Pacific Northwest Region

  Waters to the Strait of Georgia and the Juan de Fuca Strait , waters to the Pacific Ocean within the states of Washington and Oregon, and the parts of the Great Basin located in Oregon

• 18. California Region

  California waters to the Pacific Ocean and the Great Basin

• 19. Alaska Region

  All waters in the state of Alaska

• 20. Hawaii region

  All waters in the state of Hawaii

• 21. Caribbean Region

  All waters in the Commonwealth of Puerto Rico , the US Virgin Islands and the rest of the United States in the Caribbean .

Annotation:

1. ↑ Under 21030001, the Canal Zone unit was previously listed here , which includes all waters that flow into the Panama Canal . Today, apart from the previously mentioned areas of Puerto Rico and the US Virgin Islands, this only affects Navassa .

See also

• River basin district - EU system

proof

• Paul R. Seaber, F. Paul Kapinos, and George L. Knapp. United States Geological Survey . Water suppy. Paper 2294. US Department of the Interior. 1987. New edition 1994.