Why Do Rivers Flow South? (Discover 5 Rivers that Break the “Rule”)

why do rivers flow south

Written by Kyle Glatz

Updated: February 5, 2023

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Key Points:

  • Most rivers in the world flow downhill, often South, due to gravity.
  • The Nile River is an exception to this rule, flowing from South to North.
  • Other rivers have the ability to flow different directions due to where sloping occurs away from their headwaters.

Rivers are wondrous bodies of water that can measure miles across and thousands of miles in length. Many rivers have headwaters and tributaries in the mountains, and it can be tempting to think of all rivers as flowing south from northern peaks. As a result, many people have asked, “why do rivers flow south?” We will answer that question, dispel some myths, and provide you with some of the most prominent rivers that flow in other directions!

Why Do Rivers Flow South?

Oldest Rivers - New River

Rivers flow in all directions because they follow the path of least resistance.

The idea that all rivers flow south is mistaken thinking that often stems from people thinking that water flows towards the south because they equate the direction with “down.” Otherwise, they might have a river with a south flow near them. For example, some Americans may look at the flow of the Mississippi River to buttress their mistaken beliefs that all rivers flow south.

Another mistaken belief that some people have is that rivers obtain their water from the ocean. In the case of the Nile River, looking at a map might make one think that the river obtains its water from the sea.

However, if you consider the nature of water, you can easily determine the truth of the situation. That is precisely what we’re going to explore in the next situation.

What Determines the Way a River Flows?

Oldest Rivers - Finke River

Rivers flow downhill, not necessarily south.

Gravity is the ultimate determining force in terms of water flow. Water will flow downhill from the highest point to the lowest point using the path of least resistance. Sometimes, that will make the water flow to the east, west, or north instead of south.

Aside from gravity, you have to consider the area’s topography when trying to determine a river’s course. Sometimes a river will flow southward and run into a large mountain range. Instead of flowing directly over that mountain, the water would take a path around it. Once again, that new path would greatly depend on the terrain, erosion over time, and more.

Rivers change the way they flow all the time due to changes in terrain. For example, the Mississippi River was poised to begin flowing into the Atchafalaya River due to such changes. However, human intervention led to the development of a floodgate system to prevent that from happening.

All in all, rivers flow downhill toward the lowest point, which can be any direction, depending on the landscape.

Rivers That Do Not Flow South

Many rivers around the world do not flow south. In fact, some of the most famous rivers in the world do not flow south. We’re going to look at five different rivers that flow in all sorts of directions. By the time we’re done here, you’ll see how rivers can flow east, west, north, and south!

1. Nile River: Flows North

The Nile River was once considered the longest river globally, and it’s the longest in



When some people look at the Nile River on a map, they might assume that the river gains its water from the Mediterranean Sea. That might be true if the river flowed south. However, the Nile River flows north!

Two tributaries serve as the official start of the Nile River. The confluence of the Blue Nile and the White Nile is the point of origin for the Nile River. Those rivers are located south of Egypt in areas with a higher altitude than northern Egypt, so the water flows almost due north through the nation and into the Mediterranean Sea.

The Nile River is home to many species of birds, fish, amphibians, and vertebrates. Some of the vertebrates include cobras, rock pythons, Nile crocodile, Nile monitor, and spotted-necked otter. The Nile perch and African tigerfish can be found swimming in the Nile and other freshwater in Africa.

2. Yellow River: Flows East

The Yellow River is a very long river that drains into the Bohai Sea.

The Yellow River starts in the Bayan Har Mountains and flows to its mouth at the Bohai Sea, part of the Yellow Sea and a gulf of the Pacific Ocean. It is one of the longest rivers in the world and the second-longest river in China.  Along its 3,395-mile course, the river travels east, but it also flows north, a little west, south, and east.

This river travels in all sorts of directions! It has been heavily dammed to help generate hydroelectric power throughout the country.

Various fish such as Northern pike, largemouth bass, and panfish call Yellow River home. Some rare species of mammals reside along the Yellow River, such as wild yak, Tibetan antelope, and Chinese forest musk deer.

3. Ob River: Flows Northwest

marsh vs swamp

Novosibirsk is on the banks of the Ob River.

The Ob River in Russia flows primarily northwest. It is another one of the longest rivers in the world, and it has a few sources in Russia. This river has tributaries in the Katun and Biya rivers, and these are located thousands of miles to the south of the eventual mouth of the river in the Gulf of Ob.

All told, the Ob River flows about 3,360 miles, ending in the Gulf of Ob, a bay in the Arctic Ocean.

Wildlife is thriving along the banks of the Ob River. Animals such as bear, lynx, wolverines, snow leopards, and even Siberian stags reside there. Other native mammals to the Ob include otters, minks, wolves, beavers, and Siberian moles. There are around 50 species of fish found in the river.

4. Amazon River: Flows West to East

The Amazon River is both long and remote in areas.

The mighty Amazon River flows almost across the entire continent of South America. Depending on the measurement used, this may be the longest river system in the entire world and has the largest discharge of any river in the entire world.

The Amazon River gets its water from the Rio Apurimac in Peru. From there, the river flows west to east across the continent and ends in the Atlantic Ocean. The river is massive and has many tributaries from several countries on the continent.

The Amazon Rainforest is home to 1,300 bird species, hundreds of reptiles, and over 400 types of amphibians. Not to mention, over 400 mammals species reside there. The biggest animal found in the Amazon River has to be the Amazonian Manatee, which averages 1,190 pounds. Shockingly, among the many fish, bull sharks and piranhas live in the Amazon River.

5. Mackenzie River: Flows Northwest

The Mackenzie River is part of a larger river system that includes the Slave, Peace, and Finlay rivers.

The Mackenzie River is located in the Northwest Territories of Canada. The river starts in the Great Slave Lake and flows northwest for 2,635 miles before reaching its final destination in the Arctic Ocean.

This river has supported life in this somewhat desolate part of the world for thousands of years. Also, it has the second-largest drainage basin of any river in North America. Of course, the largest drainage basin is found in the Mississippi River. The Mackenzie River may not be as recognizable as the others on this list. Still, it’s a great example of a river that flows north, even in the far northern parts of the world.

Now you know how to respond when someone asks, “why do rivers flow south?” Quite simply, they don’t all flow south. The five examples we provided that flow east, west, or north are just a few rivers that don’t adhere to the “rivers flow south” concept.

Plenty of other rivers flow in directions other than south, and you can find plenty of examples in your country with ease!

Summary: Rivers that Do Not Flow North to South

RiverFlow Direction
Nile RiverNorth
Yellow RiverEast
Ob RiverNortheast
Amazon RiverEast
Mackenzie RiverNorthwest

Up Next…

Many of us love to explore and swim in beautiful rivers. If you’re curious to learn more about some of the greatest, mysterious rivers, take a look at some of our other articles!

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About the Author

Kyle Glatz is a writer at A-Z-Animals where his primary focus is on geography and mammals. Kyle has been writing for researching and writing about animals and numerous other topics for 10 years, and he holds a Bachelor's Degree in English and Education from Rowan University. A resident of New Jersey, Kyle enjoys reading, writing, and playing video games.

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