List of largest unfragmented rivers

Last updated

This is a list of the largest river basins without fragmentation by dams in their catchments, ordered by average annual discharge.

To qualify for inclusion, a river must not only have no dams on its “main” stem, but also no dams on any tributary. For this reason, major world rivers such as the Amazon, Lena, Irrawaddy, Amur, and Fraser are disqualified because of dams on tributary streams.

Many of the rivers in this list have uncertain discharges. With the exception of those in Russia, streamgauges have seldom (if ever) been placed on the majority of the largest unfragmented river systems, due to the remoteness and/or ruggedness of the terrain in which they are located. Apart from the Fly which is clearly the largest, all ranks listed here are not perfectly certain, and there also exist a number of rivers in Sundaland that might qualify with reliable discharge data, such as the Kapuas. [1]

Continent color key
AfricaAsiaEuropeNorth AmericaOceaniaSouth America
Annual discharge color key
Over 100 cubic kilometres (24 cu mi)75 to 100 cubic kilometres (18 to 24 cu mi)50 to 75 cubic kilometres (12 to 18 cu mi)Less than 50 cubic kilometres (12 cu mi)
RankRiverBasin countriesLength of longest channel Drainage area Average discharge (m³/s)Average annual dischargeMouthNotes
1 Fly Papua New Guinea
Indonesia 		1,050 kilometres (650 mi)76,000 square kilometres (29,000 sq mi)7,000 cubic metres per second (250,000 cu ft/s)220 cubic kilometres (53 cu mi) Gulf of Papua Largest river with no dam in its catchment [2]
2 Mamberamo Indonesia 1,112 kilometres (691 mi)78,992 square kilometres (30,499 sq mi)5,500 cubic metres per second (190,000 cu ft/s)170 cubic kilometres (41 cu mi) Pacific Ocean Indonesia's second largest river after the Kapuas. [3]
3 Sepik Papua New Guinea
Indonesia 		1,126 kilometres (700 mi)80,321 square kilometres (31,012 sq mi)5,000 cubic metres per second (180,000 cu ft/s)157.7 cubic kilometres (37.8 cu mi) Pacific Ocean Often regarded as largest completely pristine river system in the world [4]
4 Pechora Russia 1,809 kilometres (1,124 mi)322,000 square kilometres (124,000 sq mi)4,533 cubic metres per second (160,100 cu ft/s)143.1 cubic kilometres (34.3 cu mi) Arctic Ocean Once the subject of a possible transfer of water into the Volga.
5 Atrato Colombia 750 kilometres (470 mi)38,600 square kilometres (14,900 sq mi)4,140 cubic metres per second (146,000 cu ft/s)131 cubic kilometres (31 cu mi) Caribbean Sea Some estimates place discharge much higher - possibly placing the Atrato second only to the Fly [5] [6]
6 Kaladan Burma
India 		350 kilometres (220 mi)30,500 square kilometres (11,800 sq mi) [7] 3,476 cubic metres per second (122,800 cu ft/s)110 cubic kilometres (26 cu mi) Bay of Bengal Discharge estimated in absence of streamgauges.
Dredging project by Indian and Myanmar governments.
7 Kikori Papua New Guinea 320 kilometres (200 mi)23,300 square kilometres (9,000 sq mi)3,274 cubic metres per second (115,600 cu ft/s)103 cubic kilometres (25 cu mi) Gulf of Papua
8 Khatanga Russia (Krasnoyarsk Krai)1,150 kilometres (710 mi)364,000 square kilometres (141,000 sq mi)3,200 cubic metres per second (110,000 cu ft/s)101 cubic kilometres (24 cu mi) Arctic Ocean Most northerly large river system in the world, with northernmost tree line in basin.
9 Purari Papua New Guinea 470 kilometres (290 mi)33,670 square kilometres (13,000 sq mi)3,000 cubic metres per second (110,000 cu ft/s)95 cubic kilometres (23 cu mi) Gulf of Papua Hydroelectric dam proposed by Queensland government, so may need to be removed from list [8]
10 Pyasina Russia (Krasnoyarsk Krai)818 kilometres (508 mi)182,000 square kilometres (70,000 sq mi)2,260 cubic metres per second (80,000 cu ft/s)71 cubic kilometres (17 cu mi) Arctic Ocean Norilsk, most northerly city over 100,000, located on main stem of river.
11 Essequibo Guyana
Venezuela 		1,000 kilometres (620 mi) [9] 69,000 square kilometres (27,000 sq mi)2,213 cubic metres per second (78,200 cu ft/s)70 cubic kilometres (17 cu mi) Caribbean Sea Largest completely unfragmented river flowing into Atlantic.
12 Anadyr Russia 1,150 kilometres (710 mi)191,000 square kilometres (74,000 sq mi)2,020 cubic metres per second (71,000 cu ft/s)64 cubic kilometres (15 cu mi) Gulf of Anadyr
13 Kuskokwim Alaska (United States)1,165 kilometres (724 mi)120,000 square kilometres (46,000 sq mi)1,900 cubic metres per second (67,000 cu ft/s)60 cubic kilometres (14 cu mi) Bering Sea Largest unfragmented river in North America.
Small dams exist on tributaries of Yukon, with which it shares a major delta.
14 Indigirka Russia (Sakha)1,726 kilometres (1,072 mi)360,400 square kilometres (139,200 sq mi)1,810 cubic metres per second (64,000 cu ft/s)57 cubic kilometres (14 cu mi) Arctic Ocean Oymyakon, often thought of as the Northern Pole of Cold, located on main stem of river.
15 Great Tenasserim Burma 300 kilometres (190 mi)17,673 square kilometres (6,824 sq mi)1,788 cubic metres per second (63,100 cu ft/s)56 cubic kilometres (13 cu mi) Andaman Sea Discharge estimated in absence of streamgauges.
16 Copper Alaska (United States)460 kilometres (290 mi)63,000 square kilometres (24,000 sq mi)1,700 cubic metres per second (60,000 cu ft/s)54 cubic kilometres (13 cu mi) Pacific Ocean
17 Stikine Canada
Alaska (United States)		539 kilometres (335 mi)52,000 square kilometres (20,000 sq mi)1,600 cubic metres per second (57,000 cu ft/s)51 cubic kilometres (12 cu mi) Pacific Ocean
18 Taz Russia 1,401 kilometres (871 mi)150,000 square kilometres (58,000 sq mi)1,540 cubic metres per second (54,000 cu ft/s)49 cubic kilometres (12 cu mi) Kara Sea
19 Courantyne Suriname
Guyana 		765 kilometres (475 mi)69,000 square kilometres (27,000 sq mi)1,500 cubic metres per second (53,000 cu ft/s)47 cubic kilometres (11 cu mi) Atlantic Ocean
20 Susitna Alaska (United States)504 kilometres (313 mi)63,400 square kilometres (24,500 sq mi)1,400 cubic metres per second (49,000 cu ft/s)44 cubic kilometres (11 cu mi) Pacific Ocean Hydropower dams proposed at present, so may not remain on list indefinitely [10]
21 Thelon Canada (Nunavut)900 kilometres (560 mi)239,332 square kilometres (92,407 sq mi)1,380 cubic metres per second (49,000 cu ft/s)44 cubic kilometres (11 cu mi) Chesterfield Inlet
22 Chari Chad
Cameroon
Central African Republic 		949 kilometres (590 mi)548,747 square kilometres (211,872 sq mi)1,200 cubic metres per second (42,000 cu ft/s)38 cubic kilometres (9.1 cu mi) Lake Chad Only dryland river with discharge over 10 cubic kilometres (2.40 cu mi) not affected by dams.
23 Olenyok Russia (Sakha)2,270 kilometres (1,410 mi) [11] 219,300 square kilometres (84,700 sq mi) [11] 1,090 cubic metres per second (38,000 cu ft/s)35 cubic kilometres (8.4 cu mi) Arctic Ocean
24 Kamchatka Russia 758 kilometres (471 mi)56,300 square kilometres (21,700 sq mi)1,050 cubic metres per second (37,000 cu ft/s)33 cubic kilometres (7.9 cu mi) Pacific Ocean
25 Laluai Papua New Guinea (Bougainville Island)35 kilometres (22 mi)464 square kilometres (179 sq mi)40 cubic metres per second (1,400 cu ft/s)1.3 cubic kilometres (0.31 cu mi) Pacific Ocean Hydropower dams proposed at present, [12] so may not remain on list permanently

See also

Related Research Articles

<span class="mw-page-title-main">Columbia River</span> River in the Pacific Northwest of North America

The Columbia River is the largest river in the Pacific Northwest region of North America. The river forms in the Rocky Mountains of British Columbia, Canada. It flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state of Oregon before emptying into the Pacific Ocean. The river is 1,243 miles long, and its largest tributary is the Snake River. Its drainage basin is roughly the size of France and extends into seven states of the United States and one Canadian province. The fourth-largest river in the United States by volume, the Columbia has the greatest flow of any river entering the Pacific outside of Asia, and the 36th greatest discharge of any river in the world.

<span class="mw-page-title-main">Snake River</span> Major river in the northwestern United States

The Snake River is a major river of the greater Pacific Northwest region in the United States. At 1,078 miles (1,735 km) long, it is the largest tributary of the Columbia River, in turn, the largest North American river that empties into the Pacific Ocean. The Snake River rises in western Wyoming, then flows through the Snake River Plain of southern Idaho, the rugged Hells Canyon on the Oregon–Idaho border and the rolling Palouse Hills of Washington, emptying into the Columbia River at the Tri-Cities in the Columbia Basin of Eastern Washington.

<span class="mw-page-title-main">Colorado River</span> Major river in the western United States and Mexico

The Colorado River is one of the principal rivers in the Southwestern United States and in northern Mexico. The 1,450-mile-long (2,330 km) river, the 5th longest in the United States, drains an expansive, arid watershed that encompasses parts of seven U.S. states and two Mexican states. The name Colorado derives from the Spanish language for "colored reddish" due to its heavy silt load. Starting in the central Rocky Mountains of Colorado, it flows generally southwest across the Colorado Plateau and through the Grand Canyon before reaching Lake Mead on the Arizona–Nevada border, where it turns south toward the international border. After entering Mexico, the Colorado approaches the mostly dry Colorado River Delta at the tip of the Gulf of California between Baja California and Sonora.

<span class="mw-page-title-main">Tigris–Euphrates river system</span> River system in the Middle East

The Tigris–Euphrates river system is a large river system in Western Asia that discharges into the Persian Gulf. Its principal rivers are the Tigris and Euphrates, along with smaller tributaries.

<span class="mw-page-title-main">Mackenzie River</span> Largest river system in Canada

The Mackenzie River is a river in the Canadian boreal forest. It forms, along with the Slave, Peace, and Finlay, the longest river system in Canada, and includes the second largest drainage basin of any North American river after the Mississippi.

<span class="mw-page-title-main">Pit River</span> River in California, United States

The Pit River is a major river draining from northeastern California into the state's Central Valley. The Pit, the Klamath and the Columbia are the only three rivers in the U.S. that cross the Cascade Range.

<span class="mw-page-title-main">Hydrograph</span>

A hydrograph is a graph showing the rate of flow (discharge) versus time past a specific point in a river, channel, or conduit carrying flow. The rate of flow is typically expressed in cubic meters or cubic feet per second . Hydrographs often relate changes of precipitation to changes in discharge over time. It can also refer to a graph showing the volume of water reaching a particular outfall, or location in a sewerage network. Graphs are commonly used in the design of sewerage, more specifically, the design of surface water sewerage systems and combined sewers.

<span class="mw-page-title-main">Mamberamo River</span> River in Indonesia

The Mamberamo is the second-longest river on the island of New Guinea, after Sepik River and the third largest in Oceania by discharge volume after Fly River and Sepik. It is located in the Indonesian province of Papua. It is the second largest river in Indonesia by volume of discharge after Kapuas River and also the widest.

<span class="mw-page-title-main">Fly River</span> River in Papua New Guinea

The Fly River is the third longest river in the island of New Guinea, after the Sepik River and Mamberamo River, with a total length of 1,060 km (660 mi). It is the largest by volume of discharge in Oceania, the largest in the world without a single dam in its catchment, and overall the 20th-largest primary river in the world by discharge volume. It is located in the southwest of Papua New Guinea and in the South Papua province of Indonesia. It rises in the Victor Emanuel Range arm of the Star Mountains, and crosses the south-western lowlands before flowing into the Gulf of Papua in a large delta. The Fly-Strickland River system has a total length of 1,220 km (760 mi), making it the longest river system of an island in the world. The 824 km (512 mi) Strickland River is the longest and largest tributary of Fly River, making it the farthest distance source of the Fly River.

<span class="mw-page-title-main">Kapuas River</span> River in West Kalimantan, Indonesia

The Kapuas River is a river in the Indonesian part of Borneo island, at the geographic center of Maritime Southeast Asia. At 1,143 kilometers (710 mi) in length, it is the longest river in the island of Borneo and the longest river in Indonesia and one of the world's longest island rivers. It originates in the Müller mountain range at the center of the island and flows west into the South China Sea creating an extended marshy delta. The delta is located west-southwest of Pontianak, the capital of the West Kalimantan province. This Kapuas River should be distinguished from another Kapuas River, which starts on the other side of the same mountain range in central Borneo but flows to the south, merging with the Barito River and discharging into the Java Sea.

<span class="mw-page-title-main">Purari River</span> River in Papua New Guinea

The Purari is a river that originates in the south central highlands especially in Kandep District of Enga Province of Papua New Guinea, flowing 630 kilometres (391 mi) though Gulf Province to the Gulf of Papua. The Purari has a 33,670 km2 (13,000 sq mi) drainage basin and is the third largest river in Papua New Guinea. The discharge varies through the year, averaging around 3,000 m3/s (110,000 cu ft/s)–4,000 m3/s (140,000 cu ft/s) at the delta.

Streamflow, or channel runoff, is the flow of water in streams and other channels, and is a major element of the water cycle. It is one runoff component, the movement of water from the land to waterbodies, the other component being surface runoff. Water flowing in channels comes from surface runoff from adjacent hillslopes, from groundwater flow out of the ground, and from water discharged from pipes. The discharge of water flowing in a channel is measured using stream gauges or can be estimated by the Manning equation. The record of flow over time is called a hydrograph. Flooding occurs when the volume of water exceeds the capacity of the channel.

<span class="mw-page-title-main">Fishkill Creek</span> Tributary of the Hudson River in southern Dutchess County, New York

Fishkill Creek is a tributary of the Hudson River in Dutchess County, New York, United States. At 33.5 miles (53.9 km) it is the second longest stream in the county, after Wappinger Creek. It rises in the town of Union Vale and flows generally southwest to a small estuary on the Hudson just south of Beacon. Part of its 193-square-mile (500 km2) watershed is in Putnam County to the south. Sprout Creek, the county's third-longest creek, is its most significant tributary. Whaley and Sylvan lakes and Beacon Reservoir, its largest, deepest and highest lakes, are among the bodies of water within the watershed.

<span class="mw-page-title-main">Middle Fork Feather River</span> River in California, United States

The Middle Fork Feather River is a major river in Plumas and Butte Counties in the U.S. state of California. Nearly 100 miles (160 km) long, it drains about 1,062 square miles (2,750 km2) of the rugged northern Sierra Nevada range.

<span class="mw-page-title-main">North Fork Clearwater River</span> River in Idaho, United States

The North Fork Clearwater River is a major tributary of the Clearwater River in the U.S. state of Idaho. From its headwaters in the Bitterroot Mountains of eastern Idaho, it flows 135 miles (217 km) westward and is dammed by the Dworshak Dam just above its mouth in north-central Idaho. Draining a rugged watershed of 2,462 square miles (6,380 km2), the river has an average flow of over 5,600 cubic feet per second (160 m3/s), accounting for a third of the discharge from the Clearwater basin. The river drains parts of Clearwater, Shoshone, Latah, and Idaho counties. Most of the watershed is managed by the U.S. Forest Service. Some of the fish of the river include westslope cutthroat trout, rainbow trout, mountain whitefish, and the threatened bull trout. It also has smallmouth bass and a kokanee salmon run, both from Dworshak Reservoir. The North Fork drainage is home to grizzly bears, cougars, deer, moose, black bear, elk, grey wolves, and osprey. The river used to have a large steelhead run before the implementation of Dworshak Dam. The North Fork of the Clearwater is located within the Clearwater National Forest

<span class="mw-page-title-main">Hayfork Creek</span> River in California, United States

Hayfork Creek is a tributary of the South Fork Trinity River in Northern California in the United States. At over 50 miles (80 km) long, it is the river's longest tributary and is one of the southernmost streams in the Klamath Basin. It winds through a generally steep and narrow course north, then west through the forested Klamath Mountains, but also passes through the Hayfork and Hyampom Valleys, which are the primary agricultural regions of Trinity County.

<span class="mw-page-title-main">Sepik</span> River on New Guinea

The Sepik is the longest river on the island of New Guinea, and the second largest in Oceania by discharge volume after the Fly River. The majority of the river flows through the Papua New Guinea (PNG) provinces of Sandaun and East Sepik, with a small section flowing through the Indonesian province of Papua.

<span class="mw-page-title-main">Spring Brook (Lackawanna River tributary)</span> River in the United States of America

Spring Brook is a tributary of the Lackawanna River in Lackawanna County and Luzerne County, in Pennsylvania, in the United States. It is approximately 17 miles (27 km) long and flows through Covington Township, Spring Brook Township, and Moosic in Lackawanna County and Pittston Township in Luzerne County. The watershed of the stream has an area of 57.2 square miles (148 km2). It is designated as a High-Quality Coldwater Fishery and a Migratory Fishery above Interstate 476 and as a Coldwater Fishery and a Migratory Fishery below it. A section is also designated as Class A Wild Trout Waters. The stream's tributaries include Panther Creek, Plank Bridge Creek, Rattlesnake Creek, Green Run, Monument Creek, and Covey Swamp Creek. It has a relatively high level of water quality and is very slightly acidic, with a pH of 6.4 to 6.9.

References

  1. ↑ "Watersheds of Asia and Oceania: AS 13 Kapuas" (PDF).
  2. ↑ David, Lawrence; Tim, Cansfield-Smith (1990). Sustainable Development for Traditional Inhabitants of the Torres Strait Region.
  3. ↑ Joesron, Loebis. Country Report Implementation of Demonstration Project Mamberamo River Basin INDONESIA.
  4. ↑ Ernst, Loffler (1977). Geomorphology of Papua New Guinea (PDF).
  5. ↑ "Flooding Analysis at the Atrato River's watershed in Colombia" (PDF).
  6. ↑ Wilmar, Loaiza Cerón (2020). "Streamflow Intensification Driven by the Atlantic Multidecadal Oscillation (AMO) in the Atrato River Basin, Northwestern Colombia". Water. 12: 216. doi: 10.3390/w12010216 . hdl: 10251/176393 .
  7. ↑ Hooper, Bruce Peter; Integrated River Basin Governance: Learning from International Experiences; p. 286. ISBN   9781843390886
  8. ↑ Energy, Origin (4 January 2016). "Media Centre - Origin Energy". www.originenergy.com.au.
  9. ↑ Rongxing Guo; Territorial Disputes and Resource Management: A Global Handbook; p. 109. ISBN   9781600214455
  10. ↑ "Streamflow Record Extension for Selected Streams in the Susitna River Basin, Alaska" (PDF).
  11. 1 2 "Freshwater Ecoregions Of the World". www.feow.org. Archived from the original on 2017-01-16. Retrieved 2013-06-04.
  12. ↑ Oxford Business Group; The Report: Papua New Guinea 2012
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.