Egypt vs. Ethiopia

While hundreds of thousands of Ethiopians starve due to a government blockade, rebels are 250km away from the capital Addis Ababa. Last time those same rebels got there, they ousted the government and remained in power for 30 years.

At the same time, Ethiopia and Egypt have been on the brink of war for years. Egypt believes its existence is threatened by Ethiopia.

The prime minister of Ethiopia won the Nobel Peace Prize in 2019.

Why is Ethiopia in a civil war?
Who will win?
Why does Egypt feel threatened?
What will they do about it?
Why did Ethiopia’s prime minister win the Nobel Prize just a year before a civil war?
Why is this area spawning so many new countries, from Eritrea to South Sudan?
Are all these events interconnected?

Egypt’s Lifeline

Egypt has been threatening Ethiopia with war for over a decade, calling it an existential threat. Why? It comes back to what we said in the past: Egypt really is just the Nile.

This map from our previous article about Egypt, The Dictatorship of the Nile, shows the Middle East and North-East Africa at night. You can see the bright lights that correspond to Egypt’s 100M citizens, who live on the river banks.

Most of Egypt’s 105M citizens live on the Nile. This area is filled with bright lights on the map above. But the Nile doesn’t stop with the lights. It goes all the way to the middle of Africa.

The Nile’s main tributaries are the White Nile, born in Uganda’s Lake Victoria, and the Blue Nile, born in Ethiopia’s Lake Tana. But these are not alike.

Most people learn that the source of the Nile is Lake Victoria and then assume that’s where most of its water comes from. Wrong. Nearly 90% of the Nile’s water comes from Ethiopia, mainly through the Blue Nile.

Egypt’s 105M people depend on the water from Ethiopia. How is that possible? Let’s zoom out.

African Water

These are all the river basins in Africa.

Each color corresponds to the regions whose rivers feed into one single river. This might be easier to see:

You can notice many things:

  • Some river basins are huge and take water from a vast area.

  • Closer to the coasts, there are lots of small river basins: they don’t have time to converge towards one of the bigger basins.

  • Interior areas tend to belong to one of these big river basins.

  • The big exception is along the Sahara: the little rain that does fall in the desert immediately evaporates from the heat, so rivers die as soon as they’re born, leaving small river basins that don’t reach the sea. We call these endorheic basins. Remember that term.

  • The big red area at the top right is the Nile.

Ok now let’s compare it to the topographic map of Africa:

So many things to highlight! For example, the Atlas mountains in the north-west force all the rain—and population—of the Maghreb onto the coasts. That’s why the populations of Morocco and Algeria are concentrated in the coastal areas.

But the part I want to focus on today is the Ethiopian Highlands.

We’ll be talking a lot about these highlands. Let’s examine what they look like. First, zooming in:

Ethiopia’s Cornucopia

This is Ethiopia, with the highlands in the middle. Now let’s see what these landscapes look like from the ground.

The mountains are very high, but wherever there’s some flat ground, agriculture thrives.

Farmland in Ethiopian Highlands

And wherever the highlands are flatter, bigger population centers have emerged, like Addis Ababa, the capital, which stands at an elevation of 2300 m (7700 ft).

The Ethiopian Highlands are so elevated that they catch most of the water from the winds, and the rainfall is very heavy.

Why does it catch so much water? Because of the winds, naturally.

Between June and September, wet monsoon winds blowing from the Atlantic Ocean into central Africa bring water all the way to Ethiopia. Between January and March, the wetter winds blow from the Indian Ocean into southern Africa, which also brings rainfall to the eastern part of Africa1. This is easiest to see here:

The consequence of this is that the desert in southern Africa is in the west (Kalahari), while in the middle of Africa, the desert is in the east (Somalia).

When the winds blow, the mountains catch that water, and everything on the other side is dry, a process called the rain shadow effect. In Africa, the mountain range that catches all this rain is the Rift Valley. Why is the Rift Valley there, catching the rain? Because of plate tectonics2. Again.

Plate tectonics in Africa are splitting the continent in two. The result is two mountain ranges with a depression in the middle called the Rift Valley. The mountain ranges from the Rift catch all the rain of the monsoon winds coming from the west. Once they pass the mountains, there’s very little water left, and that’s why Somalia is so dry.

Lake Victoria, in the center of the continent, is right in the middle of the Rift Valley. That’s why it’s a lake (it’s surrounded by mountains and their water flows into the lake), and why the surrounding area is drier than the mountainside to the west (which catches water for the Congo River).

So summarizing:

  • 105M Egyptians depend on the Nile to survive.

  • About 90% of the water in the Nile comes from Ethiopia.

  • That’s because of the Ethiopian Highlands catching almost all of the water from the monsoon winds.

  • The Ethiopian Highlands are caused by the tectonic separation of Africa along the Rift Valley, which in turn ensures that Lake Victoria receives less water because it’s on the eastern side of the mountains, and that’s why most water from the Nile comes from Ethiopia and not Lake Victoria.

And this is why Egyptian authorities are panicking about Ethiopia’s renaissance.

Ethiopia’s Renaissance

As you know, water generally means agriculture, agriculture means food, and food means population. The only exception is equatorial rainforest, where the soil is very poor. That’s why the map of African population density closely matches the map of rainfall outside of the equator.

Ethiopia’s highlands are quite similar to Mexico’s center. You can read more about that here:

Uncharted Territories
A Brief History of the Caribbean
If you’re receiving this email in your Promotions folder, please drag it into your inbox so you don’t miss it next time. This is the last free GeoHistory article before I start the next phase: the role of technology. I recently visited Puerto Rico. As I dove into its geography and history, I fell in a rabbit hole to understand why the Caribbean is the way…
Read more

High altitude and lots of rainfall together make for big population centers that are poor, because the mountains make transport very hard and expensive, which means there’s very little trade and very little wealth generation.

That’s why Ethiopia has a population of 115M, bigger than Egypt’s 105M, but the country is very  poor. You can’t tell that there are so many people from looking at nighttime satellite images, because they can’t afford light outside of the biggest cities.

Meanwhile, a few hundred miles north, that same Nile feeds 100M people downstream and gives them 15% of their electricity through a dam. Naturally, the Ethiopians have decided to build a dam too.

The Grand Ethiopian Renaissance Dam

Ethiopia is building a dam on the Blue Nile at the border with Sudan, the Grand Ethiopian Renaissance Dam, or GERD for short.

The dam will be the biggest in Africa and will triple Ethiopia’s electricity power overnight. 

Today, the dam is 80% complete and has started the second filling of the reservoir.

Now, why is Egypt so fearful of all this?

Fluid Dynamics

When I first read about Egypt’s threats to bomb the dam, I assumed Ethiopia was intending to take all the water. That would indeed be a reason to go to war, since Egypt’s existence would be threatened. 

But that’s not the case. This is mostly a hydroelectric dam, to generate cheap electricity for the entire country. Some water might indeed be used for irrigation, but I couldn’t find anything about that. So why the fear? 

1. Filling

During the filling period, less water will go downstream and reach Egypt. If the dam is filled very quickly, it could take so much water as to put Egypt’s crops at risk.

2. Drought

If there is a prolonged drought, Ethiopia could keep the water for itself. 

3. Flooding

If the GERD is at risk of flooding, the dam might release so much water that it would overwhelm dams downstream. 

4. Evaporation

By creating a new artificial lake—the reservoir—there is more water evaporation3. That means less water downstream.

Egypt’s Anxiety Attack

All in all, these fears sound a bit exaggerated, given that there are 25 dams on the Nile. This will be the biggest, but that doesn’t change its impact all that much. In fact, it will be a positive, since the dam should make the Nile more stable.

Since that water won’t be diverted to agriculture—at least not yet—Egypt shouldn’t worry about a long-term reduction in water. Also, the evaporation of the GERD reservoir will be a fraction of the evaporation of the Aswan Dam, and will be counterbalanced by less evaporation there, so they shouldn’t be concerned about that.

The only concern could be during the filling phase, but in most scenarios that shouldn’t create any problem. Enough water will flow downstream to Egypt. On top of that, it will be able to keep using the water from the Aswan Dam.

Egypt’s anxiety stems from the fear of a nightmare scenario where the dam fills at the same time as there’s a horrible drought.

This image shows the shortage of water that Egypt suffered during the 10-year drought of 1982-1992 (in blue) and what it would have looked like if the GERD was filling at the same time (in orange). Source.

That is really the only concern that Egypt should have, and it’s a speculative problem. 

Egypt’s main argument against the dam was that an old British-era agreement gave all the water rights to Egypt and Sudan. But these agreements are not just very old; Ethiopia never signed them. 

Ethiopia can simply build the dam and fill it. With no control and a fear of what might happen, Egypt is having a panic attack. The only thing it can do is watch and complain. 

If you ever hear news of Egypt complaining about the dam, you should quickly discount it. The dam is nearly built, it’s already filling, and Egypt can’t do anything about it. The only situation in which you should start paying attention is if the Aswan Dam water levels go dangerously low. In the meantime, let’s not solve problems we don’t have.

This is exactly Ethiopia’s attitude, because it needs to focus on problems it does have: its civil war. And that civil war is caused by the same thing that causes the conflict with Egypt: the Ethiopian Highlands.


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If you’ve been paying attention you will have noticed that this is against the usual winds that blow at the equator from east to west. This is typical of monsoon winds. The same is true in Asia: during summer, the sun heats the land faster than the sea, so the air goes up. Colder air from the sea then floods into the land, and drops its water there. This phenomenon is stronger than that of the winds caused by the rotation of the earth.


If you’ve been reading my articles, you know this by now!


The amount of surface between the water and the atmosphere increases. There is also more surface for the sun to heat.