Why Are Some Rivers Brown?

Have you ever come across a river that was brown in color? In fact, there are many rivers that have a different color – namely brown – in most parts of the world. If you are curious to know why some rivers are brown, look no further because we will tell you the exact reason why.

Some rivers are brown due to the erosion of river banks. The soil causes the color to change to brown. Also, certain living organisms can also change the natural color of the river.

Not all rivers that are brown are dirty. If you are curious to know about other reasons why some rivers are brown, make sure to continue reading and find out more!

Erosion of Soil

As aforementioned, erosion of river banks is the most common reason why a river might turn brown. After a heavy storm, the river banks can erode, causing the soil to mix with the water. If enough of the soil is mixed with the river, the color will eventually shift to brown.

Plus, clay can also cause the river to change its color to brown or a shade of yellow. 

While it might look like this is a permanent change, that is not the case at all. If the river is carrying fewer sediments, the color change is only temporary. However, if there are enough sediments, the change in color might be permanent in some cases. 

Increased Amount of Carbon

In certain cases, an increased amount of carbon intake can cause a river to turn brown as well. There is a huge amount of carbon is stored in the form of organic deposits in soils. When that gets mixed with the river, the water will eventually change its color to brown.

While it doesn’t necessarily mean that the river is dirty, it is best if you avoid swimming in it or drinking it due to the high amount of carbon present. 

Watch this video to see the phenomenon of the Gulf of Mexico meeting the Mississippi River: 

Breaking Down of Organic Materials

Over time, organic materials such as leaves, barks, or roots will break down and mix with the water. This is a part of the natural process and it can cause the water to have a stained brown color.

In most cases, the water will remain transparent but still have a shade of brown. In that case, it means that the water is clean but due to the breaking down of organic materials, it has changed color. 

The Water is Dirty

This is one of the most common reasons why a river might be brown in color. Whether this is due to the excess amount of plastic or garbage being thrown in the river or due to the mud mixing with it, the color of the water changes to brown. In fact, some rivers are colored green as well due to algae.


That’s everything you need to know about “why are some rivers brown”. These are the main reasons why a river might change its color and turn brown. Keep in mind that not all brown rivers are dirty. Share this with a friend or family to let them know about this as well!

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