Watersheds

The Allegheny River Watershed straddles the border between New York and Pennsylvania. The headwaters are in the Southwest corner of New York. The Allegheny River joins the Ohio River in Pennsylvania where it eventually drains into the Mississippi River and Gulf of Mexico. 

Watershed Commission: Ohio River Valley Water Sanitation Commission 

Location: Southwestern Corner of New York  

• Much of Chautauqua and Cattaraugus, and 
• Portions of Allegany 

Size: 1,927 square miles of land area within New York. 

Rivers and Streams: 3,973 miles of freshwater rivers and streams. Major tributary watersheds within the Allegheny River Watershed: 

• Allegheny River (30 river miles)  
• Conewango Creek (59 miles) 

Lakes, Ponds, and Reservoirs: 24 significant freshwater lakes, ponds, and reservoirs (19,629 acres): 

• Chautauqua Lake (13,163 lake acres) 
• Allegheny River Reservoir (4,488 lake/reservoir acres) 
• Cassadaga Lake (195 lake acres) 
• Quaker Lake (275 lake acres) 
• Bear Lake (116 lake acres) 

The Atlantic Ocean/Long Island Sound Watershed drains most of the New York City Metropolitan Area and all of Long Island. Located in the Southeast corner of New York State, the watershed encompasses all marine waters in New York Harbor, Long Island Sound, Block Island Sound, and along the South Shore of Long Island, and the fresh waters that drain into them. The Atlantic Ocean Coastline stretches for 117.5 miles from Rockaway Point at New York Bay to Montauk Point in Eastern Suffolk County.

Location: Southwestern New York State

• All of Kings (Brooklyn), Queens, Nassau, and Suffolk Counties,
• Much of New York (Manhattan) and Bronx Counties, and
• Portions of southern Westchester County

Size: 1,650 square miles of land area within New York State.

Rivers and Streams: 522 miles of freshwater rivers and streams. Major tributary watersheds within the larger Atlantic/Long Island Sounds Watershed:

• Bronx River (63 river/stream miles) 63 river/stream
• Mamaroneck River (43 miles)
• Mianus River (43 miles)
• Peconic River (29 miles)

Lakes, Ponds and Reservoirs: 132 significant freshwater lakes, ponds, and reservoirs (6,728 acres):

• Kensico Reservoir (2,503 lake/reservoir acres)
• Lake Ronkonkoma (226 acres)

Estuary Waters: 905,934 acres (1,415 square miles) of marine estuary waters.

Ocean Coastline: 118 miles of Atlantic Ocean Coastline.

The Black River drains the western slope of the Adirondack Mountains and the eastern edge of the Tug Hill Plateau before flowing north and west and emptying into Lake Ontario. The Black River watershed is mostly forested and sparsely populated; the primary population center is located in Watertown.

Location: North central New York State

• Much of Jefferson, Lewis and Herkimer Counties, and
• Portions western Hamilton and northern Oneida Counties.

Size: 1,920 square miles of land area.

Rivers and Streams: 3,910 miles of freshwater rivers and streams. Major tributary watersheds to the Black River:

• Moose River (872 river/stream miles)
• Beaver River (624 miles)
• Independence River (207 miles)
• Deer River (201 miles)

Lakes, Ponds and Reservoirs: 179 significant freshwater lake and reservoir segments (33,500 acres):

• Stillwater Reservoir (6195 lake/reservoir acres)
• Fulton Chain of Lakes (4310 acres)
• Lake Lila (1,414 acres)
• Big Moose Lake (11,286 acres)
• Woodhull Lake (1,258 acres)

The Chemung River Watershed (2,600 square miles) straddles the border between New York and Pennsylvania. The waters of the Chemung River flow across the western portion of Southern Tier of New York State before joining the Susquehanna River and eventually emptying into the Chesapeake Bay. The Chemung Watershed represents about one-eighth of the larger Susquehanna River Basin.

Location: Southern Tier of New York State

• Most of Chemung and Steuben Counties,
• Portion of southwestern Schuyler and western Allegany Counties, and
• Small parts of Yates, Ontario, and Livingston Counties.

Size: 1,740 square miles of land area within New York State.

Rivers and Streams: 4,086 miles of freshwater rivers and streams. Major tributary watersheds to the 41 miles of Chemung River in New York State:

• Cohocton River (1,099 river miles )
• Tioga/Canisteo Rivers (979 miles)

Lakes, Ponds and Reservoirs: 23 significant freshwater lakes, ponds, and reservoirs (2,904 acres):

• Lamoka Lake/Mill Pond (825 acres)
• Waneta Lake (781 acres)
• Almond Lake (480 acres)

The Delaware River Watershed (12,800 square miles) covers parts of New York, Pennsylvania, New Jersey and Delaware. About one-fifth of the upper watershed lies within New York State. These headwaters originate in the Catskill Mountains and eventually flow into Delaware Bay and the Atlantic Ocean. The Delaware River (and a portion of the West Branch) serve as the border between New York and Pennsylvania.

Location: Southeastern New York State

• Most of Sullivan and Delaware Counties,
• Portions of western Orange and Ulster and eastern Broome Counties, and
• Small parts of Greene, Schoharie and Chenango Counties.

Size: 2,390 square miles of land area within New York State

Rivers and Streams: 4,062 miles of freshwater rivers and streams. Major tributary watersheds to the 79 miles of the Delaware River in New York State:

• East Branch Delaware River (1,285 river/stream miles)
• West Branch Delaware River (981 miles)
• Neversink River (626 miles)
• Mongaup River (344 miles)

Lakes, Ponds and Reservoirs: 188 significant freshwater lakes, ponds, and reservoirs (24,932 acres):

• Pepacton Reservoir (5,185 lake/reservoir acres)
• Cannonsville Reservoir (4,605 acres)
• Neversink Reservoir (1,469 acres)

The Genesee River Watershed is almost entirely within New York State, except for the upper 15 miles of the river and it drainage which originate in the Allegheny Plateau of Northern Pennsylvania. The river flows north for about 140 miles before emptying into Lake Ontario at Rochester.

Location: Western New York State

• Most of Livingston and Allegany Counties,
• Much of Monroe, Genesee and Wyoming Counties,
• Portion of western Ontario County, and
• Small parts of Orleans, Steuben and Cattaraugus Counties.

Size: 2,373 square miles of land area within New York State.

Rivers and Streams: 5,048 miles of freshwater rivers and streams. Major tributary watersheds to the 144 miles of the Genesee River in New York State include:

• Cassadaga Creek (828 river miles)
• Honeoye Creek (644 miles)
• Oatka Creek (425 miles)
• Black Creek (377 miles)

Lakes, Ponds and Reservoirs: 31 significant freshwater lakes, ponds, and reservoirs (13,288 acres), including

• Conesus Lake (3,208 acres)
• Mount Morris Reservoir (2,074 acres)
• Hemlock Lake (2,081 acres)
• Honeoye Lake (1,797 acres)

The Lake Champlain Watershed (8,234 square miles) drains the area between the Adirondack Mountains in northeastern New York State and the Green Mountains in northwestern Vermont. The long, narrow and deep lake has its outlet at its northern end where it flows through the Richelieu River into Quebec and empties into the Saint Lawrence River.

Location: Northeastern New York State

• Most of Clinton County,
• Much of Essex County,
• Southwest portion of Franklin County,
• Eastern portion of Warren County, and
• Northern portion of Washington County.

Size: 3,050 square miles of land area within New York State.

Rivers and Streams: 4,883 miles of freshwater rivers and streams. Major tributary watersheds to Lake Champlain in New York State:

• Ausable River (767 river miles)
• Saranac River (662 miles)
• Great Chazy River (545 miles)
• Boquet River (532 miles)
• Mettawee River (390 miles)
• Ticonderoga Creek/Lake George (380 miles)

Lakes, Ponds and Reservoirs: Excluding Lake Champlain (278,480 acres), 235 significant freshwater lakes, ponds, and reservoirs (159,302 acres):

• Lake George (28,523 acres)
• Upper Saranac Lake (4,844 acres)
• Lower Saranac Lake (2,145 acres)
• Lake Placid (1,954 acres)

The Lake Ontario and Minor Tributaries Watershed is comprised of the smaller drainage that lie between the larger rivers that empty into Lake Ontario. The larger rivers include the Niagara, Genesee, Oswego and Black River which are discussed as separate watersheds. The Lake Ontario Minor Tribs Watershed is divided into western, central and eastern sections that stretch all along the Lake Ontario Shoreline.

Location: Northwestern New York State

• Most of Jefferson and Orleans Counties,
• Much of Oswego, Wayne, Monroe and Niagara Counties, and
• Portions of northern Cayuga and western Lewis Counties.

Size: 2,460 square miles of land area within New York State, excluding the larger/separate watersheds.

Rivers and Streams: 5,891 miles of freshwater rivers and streams. Major tributary watersheds to Lake Ontario (excluding the Niagara, Genesee, Oswego and Black Rivers, which are addressed as separate watersheds):

• Salmon River (639 river miles)
• Oak Orchard Creek (523 miles)
• Irondequoit Creek (316 miles)
• Sandy Creek (303 miles)

Lakes, Ponds (Embayments) and Reservoirs: 60 significant freshwater lakes, ponds, and reservoirs (18,042 acres):

• Salmon River Reservoir (3,380 acres)
• Sodus Bay (3,360 acres)
• North Pond (2,400 acres)
• Irondequoit Bay (1,720 acres)
• Perch Lake (1,480 acres)

Great Lakes Shoreline: 326 miles of Great Lakes (Lake Ontario) shoreline.

The Niagara River/Lake Erie Watershed is comprised of the Niagara River that flows north from Lake Erie into Lake Ontario and forms part of the border between New York and Ontario, Canada. The watershed includes historical landmarks like the Erie Canal and Niagara Falls. 

Watershed Program: Great Lakes Watershed Program  

Watershed Commission: Great Lakes Commission 

Size: 2,376 square miles of land area within New York 

Rivers and Streams: 5,314 miles of freshwater rivers and streams.  

• Tonawanda Creek (90 miles) 
• Buffalo River (135 miles) 
• Cattaraugus Creek (68 miles) 

Lakes, Ponds, and Reservoirs: 25 significant freshwater lakes, ponds, and reservoirs (977 acres): 

• Attica Water Supply Reservoir (173 lake/reservoir acres) 
• Lime Lake (159 acres) 
• Java Lake (53 acres) 

The Lower Hudson Watershed makes up about 40% of the larger Hudson/Mohawk River Basin which is one of the largest drainage areas on the eastern seaboard of the United States. Most of this 12,800 square mile basin lies in New York State, with small portions in New Jersey, Connecticut, Massachusetts and Vermont. The Lower Hudson Watershed extends from the Battery at the southern end of Manhattan to the Troy Dam at the confluence of the Mohawk River. Along this entire 153 mile reach the Hudson is actually a tidal estuary, rather than a river.

Location: Southeastern New York State.

• Most of Westchester, Putnam, Orange, Ulster, Columbia and Albany Counties,
• Much of western and central Dutchess, eastern Greene, and southern Rensselaer Counties, and
• Smaller parts of New York (Manhattan), Bronx, Rockland, Sullivan, Schoharie and Schenectady Counties.

Size: 4,982 square miles of land area within New York State (excluding the Upper Hudson and Mohawk River Watersheds, which are addressed separately).

Rivers and Streams: 8,861 miles of freshwater rivers and streams. Major tributary watersheds to the Hudson River Estuary (excluding the Upper Hudson and Mohawk Watersheds):

• Rondout/Wallkill Rivers (1,584 river/stream miles)
• Stockport/Kinderhook Creeks (1,077 miles)
• Catskill Creek (927 miles)
• Esopus Creek (631 miles)
• Croton River (607 miles)

Lakes, Ponds and Reservoirs: 324 significant freshwater lakes, ponds, and reservoirs (37,676 acres):

• Ashokan Reservoir (8,060 lake/reservoir acres)
• Rondout Reservoir (2,024 acres)
• New Croton Reservoir (1,949 acres)
• Alcove Reservoir (1,363 acres)
• Cross River Reservoir (899 acres)
• Muscoot/Upper New Croton Reservoir (770 acres)

Estuary Waters: 78,322 acres of estuary along the entire 153 mile length of the Lower Hudson.

The Mohawk River Watershed lies entirely within the borders of New York State. The Mohawk River originates in the valley between the western Adirondacks and the Tug Hill Plateau and flows 140 miles to the east where it joins the Hudson River. The Mohawk Watershed comprises about one-quarter of the larger Hudson River Basin. Sections of the Mohawk River also serve as the New York State Barge (Erie) Canal.

Location: Central New York State

• All of Montgomery County,
• Most of Schoharie County,
• Much of Schenectady, Greene, Fulton, Herkimer and Oneida Counties, and
• Smaller parts of Albany, Saratoga, Delaware, Otsego, Hamilton, Madison and Lewis Counties.

Size: 3,460 square miles of land area, all within New York State

Rivers and Streams: 4,086 miles of freshwater rivers and streams. Major tributary watersheds to the 140 miles of the Mohawk River:

• Schoharie Creek (1,650 river miles)
• West Canada Creek (1,165 miles)
• East Canada Creek (515 miles)

Lakes, Ponds and Reservoirs: 135 significant freshwater lakes, ponds, and reservoirs (18,315 acres):

• Hinkley Reservoir (2,684 acres)
• Delta Reservoir (2.376 acres)
• Peck Lake (1,426 acres)
• Schoharie Reservoir (1,132 acres)

The Housatonic River Watershed straddles the border between New York, Connecticut, and Massachusetts. Most of the watershed is located outside of New York. The Housatonic River drains into the Long Island Sound in Milford, Connecticut.  

Location: Eastern New York 

• Parts of Columbia and Dutchess counties 

Size: 218 square miles of land area within New York. 

Rivers and Streams: 379 miles of freshwater rivers and streams. Major tributary watersheds within the larger Atlantic/Long Island Sounds Watershed: 

• Green River (10 river miles) 
• Tenmile River (15 river miles) 

Lakes, Ponds, and Reservoirs: 14 significant freshwater lakes, ponds, and reservoirs (569 acres): 

• Indian Lake (97 lake acres) 
• Quaker Lake and French Lake (64 lake acres) 
• Swift Pond and Crane Pond (135 lake acres) 

The Oswego River/Finger Lakes Watershed is one of the largest in New York State and includes the drainages of the Oswego, Oneida, Seneca and Clyde Rivers. Its headwaters originate in the southwestern Adirondack Mountains in the east and along the northern edge of the Appalachian Plateau and flow across the central lowlands before emptying into Lake Ontario. The watershed includes most of the New York Finger Lakes; in fact, lakes make up about 6% of the total surface area of the watershed.

Location: Central New York State

• All of Seneca County,
• Most of Onondaga, Cayuga, Tompkins, Schuyler, Yates and Ontario Counties,
• Much of Oswego, Oneida, Madison and Wayne Counties, and
• Smaller parts of Lewis, Cortland, Chemung, Steuben and Livingston Counties.

Size: 5,070 square miles of land area entirely within New York State.

Rivers and Streams: 8,896 miles of freshwater rivers and streams. Major tributary watersheds to the Oswego River and Finger Lakes:

• Oneida River (2,330 river miles)
• Clyde River (1,630 miles)
• Cayuga Lake Tributaries (1,500 miles)
• Seneca Lake Tributaries (1,240 miles)

Lakes, Ponds and Reservoirs: 76 significant freshwater lakes, ponds, and reservoirs (189,722 acres):

• Oneida Lake (51,091 acres)
• Cayuga Lake (42,812 acres)
• Seneca Lake (42,646 acres)
• Keuka Lake (11,712 acres)
• Canandaigua Lake (10,605 acres)

The Ramapo River Watershed straddles the border between New York and New Jersey. The Ramapo River drains into Pompton River and eventually drains into Newark Bay.  

Watershed Commission: Greenwood Lake Commission 

Location: Southeastern New York 

• Parts of Orange and Rockland counties  

Size: 218 square miles of land area within New York. 

Rivers and Streams: 304 miles of freshwater rivers and streams. 

• Ramapo River (22 river/stream miles) 
• Hackensack River (10 miles) 
• Mahwah River (10 miles) 

Lakes, Ponds, and Reservoirs: 35 significant freshwater lakes, ponds, and reservoirs (5,162 acres): 

• Greenwood Lake (1,074 lake acres) 
• DeForest Lake (720 acres) 
• Rockland Lake (276 acres) 

The Saint Lawrence Watershed lies at the border of New York State and Canada. The Saint Lawrence River serves as the gateway between the North Atlantic and the Great Lakes. At its most downstream point in the Unites States the Saint Lawrence drains an area of nearly 300,000 square miles. Within New York State the watershed drains the northern and western Adirondack Mountains and the lake plain region of the Saint Lawrence Valley.

Location: Northern New York State

• All of Saint Lawrence County,
• Most of Franklin County,
• Much of northern Jefferson, Lewis, Herkimer and Hamilton counties, and
• Small parts of western Essex and Clinton Counties.

Size: 5,600 square miles of land area in New York State.

Rivers and Streams: 11,371 miles of freshwater rivers and streams. Major tributary watersheds to the 185 miles of Saint Lawrence River shoreline:

• Oswegatchie River (3,590 river/stream miles)
• Raquette River (2,016 miles)
• Saint Regis River (1,734 miles)
• Grass River (1,607 miles)
• Indian River (1,222 miles, included within the Oswegatchie watershed)

Lakes, Ponds and Reservoirs: 376 significant freshwater lakes, ponds, and reservoirs (85,723 acres):

• Black Lake (7,754 lake/reservoir acres)
• Cranberry Lake (6,795 acres)
• Raquette Lake (5,194 acres)
• Tupper Lake (4,858 acres)
• Long Lake (4,094 acres)

Great Lakes Shoreline: 185 miles of Great Lakes (Saint Lawrence River) shoreline.

The Susquehanna River Basin is the second largest - next to the Ohio River Basin - east of the Mississippi River. The 444 miles of the Susquehanna drain 27,500 square miles covering large parts of New York, Pennsylvania and Maryland before emptying into the Chesapeake Bay. Two separate Susquehanna River Basin watersheds drain portions of south-central New York State: The Upper Susquehanna Watershed (discussed here) and the Chemung River Watershed (addressed separately).

Location: Southern Tier of New York State

• Most of Broome, Chenango, Cortland, Otsego and Tioga Counties,
• Portions of northern Delaware, southern Madison and eastern Chemung Counties, and
• Small parts of Schuyler, Tompkins, Onondaga, Oneida, Herkimer and Schoharie Counties.

Size: 4,520 square miles of land area within New York State, excluding the Chemung River Watershed.

Rivers and Streams: 8,185 miles of freshwater rivers and streams. Major tributary watersheds to the 148 miles of the Susquehanna River in New York State include:

• Chenango River (2,796 river/stream miles)
• Tioughnioga River (1,293 miles, within the Chenango River Watershed)
• Unadilla River (935 miles)
• Owego Creek (766 miles)

Lakes, Ponds and Reservoirs: 130 significant freshwater lakes, ponds, and reservoirs (16,521 acres), including:

• Otsego Lake (4,083 lake/reservoir acres)
• Canadarago Lake (1,882 acres)
• Whitney Point Lake/Reservoir (1,235 acres)

The Upper Hudson River Watershed originates in the Adirondack Mountains and flows south to the Hudson River confluence with the Mohawk River at the Troy Dam. The watershed lies primarily in New York State River but also drains a portion of southwestern Vermont and a small part of Massachusetts. The Upper Hudson Watershed makes up about one-third of the larger Hudson River Basin, which also includes the Mohawk River Watershed.

Location: Northeastern New York State

• Most of Saratoga, Washington and Warren Counties,
• Much of Essex and Hamilton Counties, and
• Portions of northern Rensselaer and northeastern Fulton Counties.

Size: 4,620 square miles of land area within New York State

Rivers and Streams: 7,140 miles of freshwater rivers and streams. Major tributary watersheds to the Upper Hudson River:

• Sacandaga River (1,740 river/stream miles)
• Schroon River (822 miles)
• Fish Creek (551 miles)
• Hoosic River (533 miles)
• Batten Kill (334 miles)

Lakes, Ponds and Reservoirs: 229 significant freshwater lakes, ponds, and reservoirs (76,940 acres):

• Great Sacandaga Lake (26,800 lake/reservoir acres)
• Indian Lake (4,465 acres)
• Schroon Lake (4,130 acres)
• Saratoga Lake (4,030 acres)