Rivers, streams, and drainage features

St. Johns River

The St. Johns River is Florida's longest river, flowing about 310 miles north from Indian River County marshes to the Atlantic at Mayport, with a one-inch-per-mile gradient, twice-daily tidal reversal, Timucua and French colonial history, and the Port of Jacksonville at its mouth.

St. Lawrence River

The St. Lawrence River (fleuve Saint-Laurent) drains the Great Lakes to the Atlantic, about 800 miles long with freshwater, estuary, and Gulf sections; home of the 1959 St. Lawrence Seaway and IJC-regulated Lake Ontario outflows.

St.Lawrence

St.Lawrence, FEOW freshwater ecoregion 117, a temperate coastal rivers ecoregion in Canada and the US defined by the St. Lawrence River drainage from Lake Ontario to the Gulf, home of the endemic copper redhorse.

Stewart

Stewart: chiefly the Stewart River (Náhcho Nyäk), a 51,000 km² tributary of the Yukon River in Yukon, Canada, named for James G. Stewart in 1851; also a Yukon settlement, an Alaska river near Nome, and a Queensland sub-basin.

Stikine River

Stikine River (Shtax'héen, "Great River" in Tlingit): a 640 km transboundary river from BC's Spatsizi Plateau to Wrangell, Alaska; fourth-longest in BC, Tahltan territory, with a 300 m deep Grand Canyon, abandoned BC Hydro dam plans, and Red Chris and Galore Creek mines on its Iskut tributary.

Stream

Stream: a body of flowing water in a defined channel, from headwater creeks to rivers (USGS FCode 46000). Covers streamflow, watersheds, sediment, classification systems, and restoration frameworks.

Stream bank

Stream bank: the sloping ground bordering a stream channel, also called streambank. Erodes by fluvial erosion and mass failure, measured as horizontal bank loss (cm/y), and is managed through stabilization practices like jetties and toe protection.

Stream bend

Stream bend (meander bend): a curve in a stream channel where faster outer flow erodes a cut bank while slower inner flow builds a point bar, driving lateral and downstream migration, cutoffs, and oxbow lakes; geometry follows a length-to-radius ratio near 4.7.

Stream mouth

Stream mouth (river mouth): the place where a stream or river discharges into a larger stream, lake, lagoon, reservoir, or the sea; the terminus where alluvium is deposited, forming deltas, mouth bars, and estuaries.

Sudanic Congo - Oubangi

Sudanic Congo - Oubangi (FEOW ID 535) is an Afrotropic freshwater ecoregion covering the Ubangi basin except the Uele, plus the Congo mainstem to Malebo Pool, with fauna transitional between Nilo-Sudanian and Congolian.

Sura (landform)

Sura (Сура) is a right tributary of the Volga in Russia, 841 km long with a 67,500 km² basin, rising on the Volga Upland and entering the Cheboksary Reservoir at Vasilsursk; distinct from India's Suru River.

Susquehanna

Susquehanna River, largest Chesapeake Bay tributary, flows through Pennsylvania and Maryland; ~38,300 cfs average discharge, 71,250 km² watershed, four lower-river hydroelectric dams including Conowingo, named for the Susquehannock people.

Susquehanna River

Susquehanna River: 444-mile river from Otsego Lake, Cooperstown, NY, to Chesapeake Bay at Havre de Grace, MD; largest US river entirely within the country draining to the Atlantic; 27,500 sq mi basin; Conowingo, Holtwood, Safe Harbor dams.

Oct 15, 2026

Susquehanna River Basin Commission

The Susquehanna River Basin Commission (SRBC) is a federal-interstate agency regulating the Susquehanna River Basin's water resources under a 1970 compact, headquartered in Harrisburg, Pennsylvania.

Sutlej (सतलुज)

Sutlej (सतलुज, Satluj), easternmost and longest of the five Punjab rivers, an Indus tributary rising in Tibet at 4,572 m, dammed by Bhakra, allocated to India under the 1960 Indus Waters Treaty, joining the Indus via the Panjnad near Mithankot.

Syr Darya (سیردریا)

Syr Darya (سیردریا), ancient Jaxartes, is a major Central Asian river rising in Kyrgyzstan and flowing to the Aral Sea; heavily diverted for Soviet irrigation, it drove the Aral's shrinkage and is now managed under transboundary agreements.

Tagus

Tagus (Tajo, Tejo): longest river of the Iberian Peninsula, rising in Spain's Sierra de Albarracín and flowing about 1,000–1,100 km to the Atlantic at Lisbon; heavily dammed, with the Tagus-Segura transfer and Spain-Portugal water disputes.

Tana, Athi & Coastal Drainages

Tana, Athi & Coastal Drainages (FEOW ecoregion 567) is a tropical coastal-river freshwater ecoregion in Kenya and northern Tanzania, covering the Tana and Athi/Galana-Sabaki basins plus smaller Indian Ocean coastal rivers, with a depauperate fish fauna, rich bird and reptile life, and the Tana Delta Ramsar site.

Tapajós

Tapajós, major clearwater Amazon tributary in Brazil, formed by the Teles Pires and Juruena rivers; 13,500 m3/s mean discharge, a sediment-trapping ria lower course, gold-mining mercury issues, and major planned dams.

Tapajos - Juruena

Tapajos - Juruena is a freshwater ecoregion in Brazil, covering the Rio Tapajós basin, a clearwater Amazon tributary with nearly a quarter of its fish species endemic.

Tapti River

The Tapti River, also called Tapi, is a 724 km west-flowing river of peninsular India, rising in the Satpura range in Madhya Pradesh and emptying into the Gulf of Khambhat.

Tarim

Tarim: the Tarim River (塔里木河), China's longest inland river at 1,321 km, and its endorheic basin around the Taklamakan Desert in Xinjiang; fed by Khotan, Yarkand, and Aqsu rivers, historically ending at Lop Nor or Taitema Lake, with ecological water diversion restoring the lower reaches since 2000.

Taz

Taz (Таз), a 1,401 km river in Western Siberia's Yamalo-Nenets Okrug flowing from the Siberian Uvaly to the Kara Sea's Tazovskaya Guba; a pristine permafrost river with 150,000 km² basin, spring snowmelt flood, and 815 km of navigation.

Teays - Old Ohio

Teays - Old Ohio (FEOW ecoregion 150) is a Nearctic temperate upland rivers freshwater ecoregion covering the Ohio River watershed across ten US states, named for the preglacial Teays River, with 208 fish and 122 mussel species.

Teesta River (তিস্তা নদী)

Teesta River (তিস্তা নদী), a transboundary Himalayan river of Sikkim, West Bengal, and Bangladesh joining the Brahmaputra; known for the unsigned 2011 India-Bangladesh water-sharing agreement, the Gajaldoba and Dalia barrages, Sikkim hydropower dams, and Bangladesh's largest irrigation project.