Most lakes go somewhere… Into a river, another lake, the ocean, something. However, some lakes feed no river, pour into no sea. These are endorheic lakes, but what does that mean? How do they form? What lives near them? Why are they important? and where does the water go?
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What is an Endorheic Basin?
Endorheic or terminal basins have no outflow, endo means ‘within’ and -rheic means ‘to flow’. Water within these regions will never reach the ocean. Instead water flows into an inland basin or depression where it accumulates.
The vocabulary does get a bit confusing. Endorheic water can refer to all the water within a basin, or the terminal water bodies. Furthermore, endorheic basins can have both exorheic and endorheic lakes. The Jordan Rift Valley in West Asia is an endorheic basin, terminating in the Dead Sea. However, the sea of Gallilee, which lies within the basin, is exorheic since it drains into the Dead Sea via the Jordan River.
Here, endorheic basin refers to the entire drainage basin. Endorheic lake or sea will refer to terminal water bodies within these basins.
If this water system sounds odd, it’s because they kind of are. 97 per cent of the terrestrial water (water found on or under continents) is exorheic — ‘exo’ meaning ‘outside’. Runoff flows into streams, which flow into lakes, which flow into rivers, until eventually the water reaches the ocean.
Without an outflow, most water loss in endorheic lakes is due to evaporation, and to a lesser extent seepage. Endorheic lakes are often salty because water evaporates but minerals don’t. Over time salts and minerals accumulate and concentrate in the water. Endorheic lakes with freshwater usually have higher levels of groundwater seepage, drawing minerals out of the lake.
How do they form?
Water naturally flows downhill, and usually the furthest thing downhill is the ocean — so most water flows towards it. If the vast majority of the earth’s water is exorheic, what prevents water in endorheic basins from reaching the ocean?
Most endorheic lakes are found in arid and semi-arid climates, or far inland. In dry regions there simply isn’t enough surface runoff to erode land barriers blocking routes to the ocean. These barriers prevent water bodies from flowing towards or draining into the ocean. Instead water collects in a low point inland, where a terminal lake forms. This is amplified the further inland you go. There needs to be enough water to reach the ocean which may be thousands of kilometres away.
Several systems that historically reached the ocean became endorheic as precipitation decreased. The Caspian Sea and Lake Chad are two examples which will be discussed later.
Endorheic lakes also form in regions that are below sea level. In these places the path to the ocean would require water to flow uphill. Instead of defying physics, water in these areas pools instead, creating an endorheic Lake.
Endorheic Lakes below sea level:
- The Caspian Sea (Azerbaijan, Iran, Kazakhstan, Russia, Turkmenistan)
- Dead Sea (Israel, Jordan, West Bank)
- Lake Assal (Djibouti)
- Lake Afdera and Lake Karum (Ethiopia)
- Salton Sea and Badwater Basin (California, U.S.A.)
- Laguna del Carbón (Argentina)
Why are they important?
A quarter of earth’s continental area falls within endorheic basins, though they contain surprisingly little water. Less than three per cent of terrestrial water is in endorheic basins — about as much water as the Yangtze River discharges annually. This water scarcity in these regions underlines the importance of endorheic lakes and ecologically and socioeconomically.
In addition to providing an accessible form of water in many region, the presence of large endorheic water bodies provide vital ecosystem services.
Larger endorheic lakes and seas impact climate by moderating temperature, humidity and precipitation much like the ocean does in coastal regions. This helps stabilize continental climates which naturally experience extreme temperature fluctuations seasonally, which enables these regions to support more abundance and diversity of life.
Inland seas and lakes form critical habitat for endemic and migratory species. These unique ecosystems also shape the cultures that inhabit them. They provide a source of water, food, transport and energy. Several empires were born along the shores of endorheic lakes. This includes the Mexica or Aztec Empire of what-is-now Mexico, and Kanem-Bornu empire of North-Central Africa.
Endorheic Water Bodies
It’s time to look at eight endorheic lakes around the world, their unique ecosystems, cultural significance, and economic importance.
Caspian Sea
- Region: Central Asia
- Nation(s): Azerbaijan, Iran, Kazakhstan, Russia, Turkmenistan
- Climate: Moderate continental climate (North), warm continental climate (middle and South), subtropical (Southwest), desert (East)
- Area: 371,000km²
- Status: At-risk (water levels decreasing)
The Caspian Sea in Central Asia is not only the largest endorheic lake, but the largest inland water body in the world by area. Located in Central Asia, five countries border the Caspian: Azerbaijan, Iran, Kazakhstan, Russia and Turkmenistan.
The drainage basin that feeds the Caspian Sea is roughly 3.6-million square kilometres — roughly two per cent of the world’s territory. One third of all inland water lies in the Caspian, with the Volga River being responsible for 80 per cent of inflow. The Ural, Terek, Sulak, Samur and Kura rivers also drain into the Caspian. Notably, the sea’s eastern shore lacks any permanent streams.
The Caspian was not always endorheic. Around 11 million years ago, The Caspian Sea drained into the ocean via the Sea of Azov, the Black Sea and the Mediterranean Sea. As tectonic plates and climate patterns shifted, the Caspian Sea was slowly cut off from the ocean, making it endorheic.
As the name suggests, the Caspian Sea is saline, though only about a third as salty as the ocean on average. Unlike the ocean, however, the Caspian Sea’s salinity varies tremendously. While the average salinity is around 12.8 parts per thousand, that figure ranges from 1 part per thousand near the Volga outlet to a whopping 200 parts per thousand in the Kara-Bogaz-Gol — where intense evaporation occurs.
The climate varies across the Caspian. The north has a moderate continental climate, the southwest has subtropical influences, and the eastern shore is desert.
Roughly 850 animal and more than 500 plant species live in or near the Caspian Sea. Some are found nowhere else in the world, like the endangered Caspian seal.
The Caspian Seal is a small, earless seal and the only marine mammal found in the Caspian. These marine mammals live on sea ice that forms in the northern during the winter, and reside in the warmer, southern waters during the summer. Their diet changes throughout the year, but consists of a variety of fish, molluscs and other invertebrates. Predators include wolves and sea eagles which hunt pups along the shore.
Humans are the primary cause of mortality for the Caspian Seal. In the 20th century, unsustainable hunting practices decimated Caspian seal populations until hunting quotas were introduced in the 1960s and 1970s. Nowadays, the seals are unintentionally caught as bycatch, primarily on illegal sturgeon fisheries. Additionally, commercial fishing, water pollution and invasive comb jellies have reduced food sources for these seals.
Fishing is a critical industry in the Caspian Sea, it’s abundant in herring, pike, perch, sprat, and sturgeon. Historically, sturgeon fished in the Caspian Sea produced the most and highest quality black caviar in the world, which comes from Beluga, Osetra, and Sevruga sturgeon. Iran and Russia were the primary producers in the Caspian, and the Russian city of Astrakhan remains the centre of caviar trade.
Transport is another important industry on the Caspian Sea. Petroleum, wood, grain, cotton, rice and sulphate are all regularly carried across the Caspian. Major ports include Astrakhan and Makhachkala in Russia, Baku in Azerbaijan, Bandar-e Anzalī in Iran, Türkmenbashi in Turkmenistan, and Aqtaū in Kazakhstan.
Energy production is also important economically within the basin. Both petroleum and natural gas are produced in the Caspian basin, primarily in the southern portion of the sea. The rivers that feed the Caspian are diverted to irrigate crops, and dams were built to generate electricity.
However, these industries are not without their impacts. Without an outflow, pollutants from industry and agriculture concentrate in the Caspian Sea’s waters, threatening wildlife and fisheries. Diversion of water for irrigation and hydroelectricity have altered the water table.
Water levels were stable in the Caspian Sea between 1840-1940. Since then there has been an overall decline in water levels (with a brief increase between 1978-1995). This decline in water levels is mainly attributed to climate change along with the construction of dams, reservoirs, and canals.
Aral Sea
- Region: Central Asia
- Nation(s): Kazakhstan, Uzbekistan
- Climate: Desert-Continental climate
- Area: ~8321km² (2018). 68,000km² (1960)
- Status: Critical (desiccated, water levels decreasing)
The Aral Sea was once the fourth largest freshwater lake in the world. Located on the border between Kazakhstan and Uzbekistan. The Aral Sea is a tragic example of how fragile endorheic systems are and how water mismanagement can lead to ecosystem collapse.
The basin that feeds the Aral Sea has an area of more than 2-million square kilometres. Headwaters from the Pamir and Tian Shen mountains feed into the Syr Darya and Amu Darya rivers, which were responsible for most of the Aral Sea’s inflow.
Historically the Aral Sea supported a diverse ecosystem, both within the sea and along its shores. The Aral was home to abundant fish, including the Aral Barbel, Aral Sturgeon and a unique subspecies of trout. Habitat along its shores, including marshes were home to black-winged stilts, Pallas’ sandgrouse, warblers and larks. Wolves, Persian gazelles, Saiga Antelopes roamed nearby.
The rich ecosystems sustained by the Aral Sea were also crucial to locals living along its shore. Abundant fisheries provided a source of food and income.
Unfortunately, the Aral Sea no longer supports the abundance and diversity of life it once did. The Aral Sea has rapidly dried up since the mid-twentieth century. So what happened?
Mismanagement of water resources within the Aral Basin ultimately led to its demise. In the 1960s the Soviet government began diverting water from the Amu Darya and Syr Darya rivers for irrigation, primarily cotton farming. Diversion of river water, paired with intensive groundwater extraction, drastically reduced inflow into the Aral Sea.
Between 1975 and 2007, the Aral Sea shrunk by 75 per cent from its original size. The effects of this have been nothing short of catastrophic for both human and wildlife regionally.
Communities in the region still grapple with the impacts of the lake’s disappearance. Fisheries and the communities that depended on them for survival collapsed as the Aral Sea dried and became increasingly saline. The loss also jeopardizes animal husbandry, which is not only important economically but culturally for the traditionally nomadic groups in the region.
The loss of the Aral Sea has led to a severe water crisis in the region. The drying of the Aral Sea created what’s now known as the Aralkum desert. As water evaporated in the sea, salt, fertilizers and pesticides concentrated and contaminated the lakebed. Dust storms now blow harmful dust from the lakebed onto surrounding cropland and communities. When the dust settles, it contaminates water sources and farmer’s fields. The dust is also a public health hazard reportedly causing several health issues affecting respiratory and reproductive systems and causing tumours.
The disappearance of the Aral Sea also impacted the regions climate. Large water bodies have a moderating effect on climate, which is why coastal regions are typically more temperate than inland areas. The drying of the Aral removed this service, leading to colder winters and warmer, drier summers.
There have been efforts to protect and restore what’s left of the Aral Sea. Kazakhstan finished building the Kok-Aral dike and dam in 2005. This dam seperates and prevents flow from the North Aral into the South Aral. As a result, water levels rose, salinity decreased, and allowed fisheries to rebound in the North.
The UN Development program partnered with Kazakhstan and Uzbekistan to plant salt and drought resistant trees around the Aral Sea in 2015. Afforestation can help to conserve water, decrease summer air temperatures, and moderate climate.
One of the biggest ongoing challenge in restoring the Aral Sea is agriculture. Ninety per cent of water consumption in Central Asia is used for irrigation. In the Aral Sea, cotton is the biggest crop, but grains like wheat, barley, and rye are also grown. Shifting production to less water-intensive crops, and using water-conscious farming practices like minimal tilling can help reduce demand for water too.
Lake Natron
- Region: East Africa
- Nation(s): Tanzania, Kenya
- Climate: Semi-arid tropical savannah
- Area: 1040km²
- Status: At-risk
In northern Tanzania lies Lake Natron, a lake of extremes. Natron is a soda lake, meaning it contains high quantities of dissolved sodium and carbonate. These dissolved minerals make Lake Natron alkaline, with a pH between 9 and 10.5 (some sources claimed as high as 12) depending on water levels, similar to that of ammonia. Water temperatures can exceed 40 degrees celsius.
Lake Natron lies in the East African Rift Valley. Here the earth’s crust is ripping itself apart. The region is full volcanic activity, which gives Lake Natron one of its defining features.
South of the lake is the Ol Doinyo Lengai volcano. This volcano is the only source of natrocarbonatite lava in the world. Most volcanic lava is high in silica, but not Ol Doinyo Lengai’s lava. Carbonatite lava has low silica, and much higher levels of minerals like calcite and dolomite.
Rich in sodium and potassium carbonates, debris from Ol Doinyo Lengai’s wash into Lake Natron. As the water evaporates, these salts and minerals concentrate in the lake which is why this lake is so caustic.
Sodium carbonate found in Lake Natron is also able to calcify animals that fall into the lake, preserving them like mummies (sodium carbonate was also used by Egyptians in mummification).
Lake Natron’s alkalinity and temperatures may lead one to think the lake is inhospitable, but it’s precisely these conditions that give the lake life.
The bright red colour in the lake comes from cyanobacteria that live in the water. Adapted to such a harsh environment, these bacteria provide a crucial food source for the lesser flamingo. The carotenoid pigments in these cyanobacteria are also responsible for making the flamingos pink!
Lake Natron is the only regular breeding ground for the near-threatened Lesser Flamingo (Phoeniconaias minor). The lake provides a source of food for the flamingos, and its caustic waters protect their nests and hatchlings from predators.
Once every few years when water levels are just right, more than 2 million lesser flamingos descend upon Lake Natron to breed, three-quarters of the world’s population. It is East Africa’s only regular breeding site for Lesser flamingos, making Lake Natron a critical area for conservation.
If Lake Natron’s water levels are too low, predators can walk across the lake to reach hatchlings. If water levels are too high, the flamingos can’t build their nest. High water levels also reduce the overall concentration of cyanobacteria, making feeding less efficient and more time-consuming. When conditions are unfavourable, Lesser flamingos will simply not breed.
One myth that’s circulated online is that Lake Natron is a skin-flaying-lake-of-instant-death-and-suffering. Some articles would have readers believing that simply stepping into the lake means certain death. While the lake is alkaline and therefore caustic, it’s not alien blood.
Even when the lake is its most alkaline, it’s not going to melt flesh. The pH of Lake Natron ranges between that baking soda and bleach. It’s not a lake one would want to swim in and extended exposure can cause burns, but if you’ve ever cleaned your home with ammonia or bleach and spilt some on skin, you know it’s not the end of the world or your existence.
Furthermore, articles online from tourism companies claim that the local Maasai people use the lake’s caustic water to clean and debride the thick skin on their feet (though I couldn’t find other sources/video confirming this).
Lake Chad
- Region: West/Central Africa
- Nation(s): Cameroon, Chad, Niger, Nigeria
- Climate: Semi-arid & arid Sahel
- Area: ~2,000km²
- Status: Endangered (water levels decreasing)
Moving from one side of the African continent to the other. On the border between Nigeria, Niger, Chad and Cameroon lies Lake Chad. The Chari River provides 90 per cent of Lake Chad’s water. This lake falls within the largest endorheic basin in Africa, the Chad Basin. The drainage area of this basin is roughly 2.5-million square kilometres and extends into the Central African Republic and Sudan.
Unlike the other lakes so far on this list, Lake Chad is freshwater. Two main factors contribute to this. The first is that the surrounding soil has relatively low salt content, so less salt is carried into the lake by rivers and runoff. The second factor is groundwater seepage. Water from Lake Chad, and dissolved minerals, seep into groundwater and aquifers. This removes salts from the lake and keeps the water fresh. Though salinity does increase when water evaporates during the dry season, particularly in the north and northeastern portions of the lake.
Like the Caspian Sea, Lake Chad wasn’t always endorheic. As recently as 7,000 years ago (recent geologically anyways), what-is-now Lake Chad was exorheic, draining into the ocean. This massive paleo-lake is known to scientists as Lake Mega-Chad.
Lake Mega-Chad was many times larger than modern Lake Chad, and existed during the African Humid Period. This period in Africa’s history was marked by higher levels of rainfall and precipitation. At this time, there was so much water that Mega-Chad was able to flow into the Benue and Niger Rivers, and eventually drain into The Atlantic Ocean. As the Humid Period ended, precipitation decreased and water levels dropped, eventually cutting of fthe Lake’s routes to the coast.
Lake Chad has a rich human and natural history. The Chad Basin has been continuously inhabited since at least 500BCE and contains the earliest discovered evidence of hominid occupation in West Africa. Nine cranial specimens belonging to Sahelanthropus tchadensis, which are ~6-7 million years old, were found in northern Chad in 2001. Before this discovery, the only specimens from early humans were found in the Great Rift Valley in Eastern Africa and sites in South Africa.
Several civilizations began along Lake Chad. The earliest of these (that we know of) is the Sao civilization, which lived along the lake from 6th century BCE to 16th century CE.
Lake Chad served as an important crossroads between North Africa, sub-Saharan Africa, and the Nile River Valley. From the 9th to 19th century Lake Chad was home to the powerful Kanem-Bornu Empire. This trading empire was ruled by the Sea (Sayf) dynasty. It wasn’t until conflict between the Kanem-Bornu and other states that the dynasty died out in 1846.
Historically, the Lake Chad region was rife with life. Visitors to the Kanem Kingdom described an abundance of wildlife including lions, hippopotamuses, and rhinoceros roaming nearby. Accounts up until the early 20th century describe similar diversity in plant and animal life.
Hundreds of bird species reside in the region both seasonally and permanently. Ostriches, Nubian bustards, secretary birds, ground hornbills, glossy ibises, and African spoonbills near the lake. Nile Crocodiles, rock pythons and spitting cobras can also be found. A rich variety of fish species live in the lake too, which are important ecologically and economically.
The well-drained soil of Lake Chad formerly sustained dense woodlands with kapok and ebony trees. However, degradation has altered the habitat, and the result has been a shift to more open woodlands comprised of acacias, baobab, palms, African myrrh, Indian jujube and other species suited to drier climates.
Today Lake Chad is a lifeline to the almost 40 million people who live along it, providing a source of water, food, and income. Fishing is a critical industry on the lake, with more than 40 species of fish considered important commercially.
Water from the Chari River is important for agriculture and urban growth. Though, like other endorheic lakes in this list, diversion of water has led to the lake shrinking by 90 per cent in the last 60 years. Urban development and agriculture have also significantly degraded the habitat and contributed to desertification. Habitat loss and climate change are ongoing threats to both biodiversity and communities.
There are ongoing efforts to try and restore Lake Chad and its surrounding environment, though there are also many challenges still to face. Development policies focus on short-term solutions, and there is a lack of integrated water management on both regional and national levels.
The region is also experiencing conflict over water resources and territory around Lake Chad. The Boko Haram insurgency has been vying for control over parts of the lake, further complicating conservation efforts. The insurgency began in 2013, and as of May 2025 more than 2.9 million people in the Chad Basin have been displaced.
On November 9, 2025, a fight for territory between Boko Haram and ISWAP (another militant group) killed more than 200 people.
Lake Chad shows how environmental conservation is inseparable from social issues. The loss of water in Lake Chad has contributed to conflict in the region, and conflict in the region impairs people’s ability to address these environmental issues.
Frame Lake
- Region: North America
- Nation(s): Canada (Northwest Territories)
- Climate: Sub-arctic boreal forest
- Area: 0.84km²
- Status: Critical (Eutrophic, no fish)
Frame Lake is located in the Yellowknife, the capital of Canada’s Northwest Territories. There’s a walking trail around the whole lake. Along is shores is Territories’ legislature and heritage museum. When the lake freezes in the winter, it becomes a thoroughfare for snowmobiles and skiers.
What’s unique about Frame Lake is that it’s not in an endorheic basin and it’s not naturally endorheic, it’s been made that way by people.
Frame Lake is located within the massive Arctic drainage basin in Canada. Historically, Frame Lake would have fed into Great Slave Lake, then the MacKenzie river, before draining in the Beaufort Sea on the Arctic Coast. The lake was home to Lake Whitefish, Northern Pike and Suckers, and was used as a fishing camp by the Yellowknives Dene First Nation, who knew the lake as Enaàti.
When industrial activity began in the region, the camp was abandoned by the Dene (as a fishing camp, the Dene still live in the Yellowknife area). Frame Lake then served as a popular locale for swimming and fishing in the 1950s and 60s. But, by 1973, studies found that the lake was devoid of fish. So what killed Frame Lake?
Gold was discovered in the Yellowknife area in 1896. In the 1930s and 40s, three mines were opened near Yellowknife: Giant mine, Con mine, and Discovery mine. Giant mine was the most successful of the three, producing a total of 7.6 million ounces of gold between 1948-2004.
The process of extracting gold from ore produces arsenic trioxide (AsO3), also known as white arsenic. This white, odourless, tasteless byproduct is highly toxic. A lack of regulation in the early days led to the release of approximately 19 million kilograms of arsenic trioxide dust into the air via stacks. This contaminated much of the Yellowknife area with arsenic trioxide, including Frame Lake. Containment methods improved in time, and 237,000 tones of arsenic trioxide dust is stored beneath the Giant mine site.
To this day Giant mine is considered Canada’s most contaminated site.
Arsenic contamination was only the beginning of Frame Lake’s death. With the mines came rapid population growth and urban development. Urbanization in Yellowknife disrupted Frame Lake’s inflow and outflow. Specifically, the construction of a major road between 1948-1964, which became a causeway in 1975, slowed outflow from Frame Lake. Eventually these changes made the lake endorheic.
Without an outflow, nutrients and pollutants concentrated the lake. This was exacerbated by the use of Frame Lake as a snow dump. In the winter, snow cleared from streets (full of salts, nutrients and other contaminants) was dumped on the frozen lake. When the ice melted in the spring, these contaminants entered the lake. Excess nutrients in the water caused eutrophication — the proliferation of algae blooms. The algae in Frame Lake depleted dissolved oxygen levels, eventually suffocating the fish within.
The case of Frame Lake is unique in that it’s one of the only lakes to become endorheic as a result of urban development and population growth. It also serves as an example of how humanity alters ecosystems, and how these alterations can have drastic, tragic and unforeseen consequences.
Recently there have been efforts to revive Frame Lake. An aerator installed at Frame Lake in 2024 now runs in the winter, circulating water within the lake and mixing it with air. The goal is to increase dissolved oxygen levels enough to sustain fish populations.
Aeration has improved water quality and prevented fish kills elsewhere in Canada. Whether the aeration is working, and if fish can be reintroduced into Frame Lake may take years to determine.
Great Salt Lake
- Region: North America
- Nation(s): United States of America (Utah)
- Climate: Arid-temperate.
- Area: 2,500km2 (2022)
- Status: Endangered (water levels decreasing)
The Great Salt Lake is a hyper-saline endorheic lake in the U.S. state of Utah. Located within is the largest endorheic basin in the Americas, the Great Basin, which spans across the southwest with an area of more than 500,000km² Though not all of this water flows into the Great Salt Lake, it’s the largest lake in the basin.
A railroad built in 1959 splits the Great Salt Lake into a north and south arm, blocking most flow between arm. The three river feed the Great Salt Lake: The Bear, Weber, and Jordan Rivers. All three rivers drain into the south arm, and provide roughly two-thirds of water enters the lake. Precipitation (31 per cent of inflow) and springs (~2 per cent) also supply the Great Salt Lake.
The causeway blocking flow between the two arms has caused the north arm to become much saltier and less hospitable than the southern arm — though both are saltier than the ocean.
The only organisms that can survive the north arm are halophiles, organisms which adapted to hyper-saline environments. Two species of bacteria are known to inhabit the north arm, which are responsible for its pinkish or violet colour.
In contrast, the southern arm boasts an abundance of life. The great Salt Lake supports 80 per cent of Utah’s wetlands, making it invaluable for wildlife in the region. The wetlands contain a mix of fresh, brackish and salt water. The different microenvironments form critical habitat for birds, fish, amphibians, reptiles and invertebrates.
The infamous “Lake Stink” around Great Salt Lake comes from bacteria living in sediment around the lake. They may be smelly, but they are also crucial for the ecosystem. The smell is caused by the production of hydrogen sulphide gas, which comes from the bacteria decomposing organic matter and recycling nutrients.
Brine flies and shrimp form the base of the Great Salt Lake’s ecosystem and food chain. these small invertebrates live in the south arm’s waters and provide an essential food source to the millions of birds that rely on the lake. Up to 12 million migratory birds from more than 330 species use Great Salt Lake for feeding, breeding and nesting. Eared grebes, bald eagles, common goldeneyes, Wilson’s phalarope, American pelicans, snowy plovers, Black-necked stilts, double-crested cormorants, white-faced ibises, and Great blue herons are just some of the bird species that depend on the Great Salt Lake.
This lake is important for Utahns beyond being the capital’s namesake. The Great Salt Lake contributes roughly 1.9 billion dollars to Utah’s economy. Over 7,700 people are employed in industries directly tied to the lake.
Great Salt Lake produces 14 per cent of the world’s supply of magnesium, which is used in computers, aircrafts, car parts, beverage cans and more; and 40 per cent of the world’s brine shrimp eggs, which are essential to aquaculture. It’s also a source of sulphate of potash, which is a critical ingredient in the production of commercial fertilizers.
Additionally, the climate created by there Great Salt Lake contributes between 5-10 per cent of Utah’s snowpack, extending skiing season by roughly 5-7 weeks (employing another 20,000 people and providing $1.2 billion to the economy).
Like many of the other endorheic lakes on this list, the Great Salt Lake has experienced a drastic decrease in area and volume over the last several decades. Upstream water diversion and overconsumption are the primary cause of the lake’s decline, though climate change is expected to worsen conditions.
In 2022, declining water levels in the GreatSalt Lake exposed 800km² of lakebed. In addition to the loss of habitat this causes, exposed lakebed creates dust that contains arsenic and other metals, which create a potential public health hazard. This dust also negatively affects agricultural production and property values. When dust from the lake lands on nearby snowpack, it causes snow to melt faster, shortening skiing season and disrupting water supplies.
Lake Texcoco
- Region: North America
- Nation(s): Mexico (Mexico City)
- Climate: Tropical highland
- Area: 101km², (Lake Texcoco, 2022). 26.57km² (Lake Xochimilco, 2004). 7,868km² (Historically).
- Status: Critical (drained).
Lake Texcoco was once a large saltwater lake system in Central Mexico. The capital, Mexico City, is built on the lakebed of what-was-once Lake Texcoco. This endorheic lake did not slowly dry up, but was deliberately drained by people.
Historically, water levels in Lake Texcoco varied seasonally, rising during the rainy season and shrinking in the drier months. The Valley of Mexico, is an elevated basin surrounded by mountains and volcanoes, which prevented water in the region from draining.
Originally Texcoco was one of five lakes in the Anáhuac, or Valley of Mexico. In the 17th century efforts began to drain the lake, but to understand why this was done, we have to go back to the colonization of Aztecs.
The capital of the Aztec Empire, Tenochtitlan, was founded on an island in Lake Texcoco. Ruled by the Mexica people, the Aztec Empire had a population of roughly 6 million people at its height, with as many as 400,000 living in the capital. The empire was built off the people’s agricultural skills, with the wetlands around Lake Texcoco being reclaimed and irrigated for crops. A complex engineering system handled both flooding and drought while providing stable food and water supplies. The lake was also critical to navigation, connecting several cities within the empire.
One ingenious form of agriculture used by the Aztecs were chinampas. Chinampas are artificial islands built in the Mexico Valley by layering vegetation, dirt, and mud. Anchored to the lakebed by tree roots, chinampas enabled intensive and productive agricultural production. This served as a strong foundation for the nation, making it possible for them to grow to become one of the largest empires ever in the Americas.
Then in 1519, Spanish conquistadors led by Hernán Cortés entered Tenochtitlan with the goal to conquer the empire. For nearly two years Spanish and Aztec forces fought one another vying for control of Tenochtitlan. Just as Lake Texcoco enabled the Aztecs to rise to power, so too would it lead to their fall. The final strategy of the Spanish was to drinking water and food supplies to the city, and their plan was effective. On August 13, 1521 the Aztecs surrendered to the Spanish. Not only was this surrender the end of the Aztec empire, it would also mark the beginning of the end for Lake Texcoco.
Once the Mexica were defeated, the next task was to build a capital for New Spain. There were several possible locations for this new city. The decision to build Mexico City on top of Tenochtitlan and Lake Texcoco is credited to Cortés. This was a calculated political measure, an assurance that conquest was final. Cortés considered it dangerous to leave the old Aztec capital free, lest the indigenous people try to reclaim or rebuild their temples, palaces and monuments.
New Spain’s capital was to be built in the image of the colonizer’s homeland. Geographer and naturalist Alexander von Humboldt noted in an 1827 publication that, “the first conquerors wanted the beautiful valley of Tenochtitlan to resemble in everything the Castilian soil, in the arid and devoid of its vegetation.”
The Spanish were not familiar with the Anahuac’s floodplains and how to inhabit them. Forests were cut down for building materials and as a fuel source. Rivers were diverted, polluted, or dried up. In 1608 the decision was made to drain the Mexico Basin and Lake Texcoco into the Tula River.
These changes to the water system caused major floods, the worst of these occurring in 1629. A deluge struck Mexico City. It rained for 40 hours continuously, submerging some parts of the city in water as high as 2 metres, and killing roughly a fifth of residents. Mexico City remained flooded for years. It wasn’t until 1634 — five years later — that a drought finally put an end to the flood.
In the 500 years since the defeat of the Aztecs, various governments have attempted prevent flooding. Canals, dikes and dams have been built over the centuries. As a result of draining and diverting water, several aquatic, semiaquatic and halophilic species have gone extinct.
The diverting, damming, draining, and desiccation of water resources in the Mexico Valley not only destroyed much of the rich ecosystem that once lived, but has also failed to prevent flooding.
The shifts in the water table paradoxically cause both floods and water scarcity. The city has to pump water out to prevent flooding, and at the same time must import clean drinking water into the city to provide for its inhabitants.
Nowadays, only a fraction of what was once Lake Texcoco and adjoining lake remains. One of particular ecological and cultural importance is Lake Xochimilco. This lake was connected to Texcoco before it was drained.
Xochimilco’s name means, “where the flowers grow” in the Nahuatl language. During the Aztec empire, Xochimilco was the agriculural centre of Tenochtitlan. Today it’s one of a few places where chinampas are still used. Despite being surrounded by urban sprawl, Xochimilco continues to be important centre for flower production and garden markets.
Xochimilco is also important for biodiversity, as the lake is home the several endemic species. A species of willow known as ahuejote (Salix bonplandiana) is crucial in preventing erosion in the region. Xochimilco is the only habitat for the axolotl, a species of salamander capable of regenerating entire limbs. The Montezuma frog and acocil (a species of crayfish), are also found nowhere else in the world.
McMurdo Dry Valleys
- Region: Victoria Land, Antarctica
- Nations: N/A
- Climate: Polar desert
- Area: 6.8km² (Lake Vida), 5.2km² (Lake Vanda), 0.25km² (Don Juan Pond)
- Status: Lake level rising
The McMurdo Dry Valleys are the driest and coldest desert on earth. Nearby mountain ranges create a ‘rainshadow’ which makes the valleys so arid. It is one of the few regions in Antarctica with soil free of snow and ice. It’s so dry that penguins and seals that wander into the valleys are mummified after death.
Located in Victoria Land, Antarctica, the valleys contain several saline endorheic lakes. In the summer temperatures in the valleys are warm enough to melt ice in nearby glaciers, which feed the lakes despite scant rainfall. Small streams form, but are unable to reach the ocean due to glaciers and mountains blocking the route. Water pools and forms lakes in the bottom several of the valleys.
Antarctica is one of the most inhospitable places on earth, and the McMurdo Dry Valleys are even more extreme. The McMurdo Dry Valleys are so arid and inhospitible that there is little surface life. Penguins and seal mummies are scattered across the valleys. Some of the mummies show signs of being scavenged by skua, a sea bird that sometimes fly through the valleys. The region is also home to
While not much survives in such a climate, the valleys are not devoid of life.
Lake Vanda is one of the largest endorheic lakes in the region. Located in the Wright Valley, Lake Vanda is fed by Antarctica’s longest river, the Onyx River. This lake is covered in ice year-round, but liquid water is found under the surface — along with life. The lakebed is home to microbial mats made of cyanobacteria are able to photosynthesize with what little light gets through the ice.
In the west end of the Wright Valley lies another endorheic water body. The Don Juan pond is a small water body fed by groundwater. The pond is only ankle deep, with an area of roughly 0.25km².
Don Juan Pond is the saltiest water body in the world. With a salinity over 40 per cent, the Don Juan Pond is so salty that the water never freezes, in Antarctica! In comparison, The Dead Sea has a salinity of 34 per cent, and the Great Salt Lake ranges between 5 and 27 per cent.
The McMurdo Dry Valleys are also a valuable place for researchers. The conditions in these hyper-saline lakes are thought to be similar to the lakes once found on Mars. By studying what lives in these Antarctic lakes, researchers are able to better understand what sort of organisms may have inhabited ancient martian lakes.
Learn More
If you want to see more of the endorheic lakes on this list, what makes these fascinating systems vulnerable, or how they can be protected, check out my latest YouTube video.
Citations
- Wang, J. (2020). “Endorheic water.” The International Encyclopedia of Geography. Accessed via https://www.researchgate.net/publication/344487528_Endorheic_water
- Yapiyev, V.; Sagintayev, Z.; Inglezakis, V.; Samarkhanov, K.; Verhoef, A. (2017). “Essentials of Endorheic Basins and Lakes: A Review in the Context of Current and Future Water Resources Management and Mitigation Activities in Central Asia.” MDPI. Accessed via https://www.mdpi.com/2073-4441/9/10/798
- McCarthy, J.; Canziani, O.; Leary, N.; Dokken, D.; White, K. (2001). “Climate Change 2001: Impacts, Adaptations, and Vulnerability.” Section 4.3.7. Lakes. IPCC. Accessed via https://archive.ipcc.ch/ipccreports/tar/wg2/index.php?idp=170
- Salisbury, S. (2025). “The World’s Largest Endorheic Lakes Explained.” World Atlas. Accessed via https://www.worldatlas.com/lakes/the-world-s-largest-endorheic-lakes-explained.html
- Owen, L. (2025). “Caspian Sea.” Encyclopedia Britannica. Accessed via https://www.britannica.com/place/Caspian-Sea
- “The Caspian Sea.” (2007). European Space Agency. https://www.esa.int/Applications/Observing_the_Earth/The_Caspian_Sea
- Rafferty, J. (2024). “Caspian Seal.” Encyclopedia Britannica. Accessed via https://www.britannica.com/animal/Caspian-seal
- “Pusa caspica (Caspian Seal).” (2016). IUCN Red List. Accessed via https://www.iucnredlist.org/species/41669/45230700
- Jensen, A. (2024). “Aral Sea | Research Starters.” EBSCO. Accessed via https://www.ebsco.com/research-starters/environmental-sciences/aral-sea
- Joger, U.; Dujsebayeva, T.; Belyalov, O.V.; Chikin, Y. (2012). Fauna of the Aralkum.” Aralkum — a Man-Made Desert. Accessed via https://www.researchgate.net/publication/225995993_Fauna_of_the_Aralkum
- Anchita; Zhupankhan, A.; Khaibullina, Z.; Kabiyev, Y.; Persson, K.; Tussapova, K. (2021). “Health Impact of Drying Aral Sea: One Health and Socio-Economical Approach.” Water. Accessed via https://www.mdpi.com/2073-4441/13/22/3196#:~:text=The%20exposed%20bottom%20of%20the,in%20the%20Aral%20Sea%20region.
- “World of Change: Shrinking Aral Sea.” (N.D.). NASA Earth Observatory. Accessed via https://earthobservatory.nasa.gov/world-of-change/AralSea#:~:text=As%20the%20Aral%20Sea%20has,became%20a%20public%20health%20hazard.
- Huseynli, O. (2024). “The Aral Sea Catastrophe: Understanding On of the Worst Ecological Calamities of the Last Century.” Earth. Accessed via https://earth.org/the-aral-sea-catastrophe-understanding-one-of-the-worst-ecological-calamities-of-the-last-century/
- Billock, J. (2016). “The Deadly Lake Where 75 Percent of the World’s Lesser Flamingos Are Born.” Smithsonian Magazine. Accessed via https://www.smithsonianmag.com/travel/flamingos-find-life-among-death-180959265/
- Byme, A., et al. (2024). “Productivity declines threaten East African soda lakes and the iconic Lesser Flamingo.” Current Biology. Accessed via https://www.sciencedirect.com/science/article/pii/S0960982224003026
- Rabdiya, A. (2025). “Controversial mining project in Tanzania’s Lake Natron halted.” Bird Life. Accessed via https://www.birdlife.org/news/2025/08/22/controversial-mining-project-in-tanzanias-lake-natron-halted/
- “Lake Natron.” (N.D.). Beach Safari. Accessed via https://beachsafari.com/en/kb/lake-natron#:~:text=Geography%20and%20Location,2%2C000%20feet)%20above%20sea%20level.
- Safarinjema. (2025). Lake Natron: Let’s Dispel the Myths & Misunderstandings.” Tanzania Safari Club. https://tanzaniasafariclub.com/lake-natron-lets-dispel-the-myths-misunderstandings/
- “Lake Natron — the Deadly Lake That Turns Animals into Stone.” (N.D.). Ultimate Kilimanjaro. Accessed via https://www.ultimatekilimanjaro.com/lake-natron-the-deadly-lake-that-turns-animals-into-stone/
- Gritzner, J. (2025). “Lake Chad.” Encyclopedia Britannica. Accessed via https://www.britannica.com/place/Lake-Chad/Plant-life
- “Remnants of an Ancient Lake.” (N.D.). NASA Earth Observatory. Accessed via https://earthobservatory.nasa.gov/images/146304/remnants-of-an-ancient-lake
- “Sahelanthropus tchadensis.” (2024). Smithsonian National Museum of Natural History. Accessed via https://humanorigins.si.edu/evidence/human-fossils/species/sahelanthropus-tchadensis
- “The tale of a disappearing lake.” (2018). United Nations Environment Program. Accessed via https://www.unep.org/news-and-stories/story/tale-disappearing-lake
- Niang, A. (2025). “Tackling security and climate challenges in the Lake Chad Basin requires collaboration.” The London School of Economics and Political Science. Accessed via https://blogs.lse.ac.uk/africaatlse/2025/08/21/tackling-security-and-climate-challenges-in-the-lake-chad-basin-requires-collaboration/
- Bello, K. (2025). “Boko Haram crush ISWAP fighters in deadly Lake Chad clash.” Daily Post Nigeria. Accessed via https://dailypost.ng/2025/11/10/boko-haram-crush-iswap-fighters-in-deadly-lake-chad-clash/
- Egbejule, E. (2025). “Terrorist turf war battle in north-eastern Nigeria leaves about 200 dead.” The Guardian. Accessed via https://www.theguardian.com/world/2025/nov/10/terrorist-turf-war-battle-north-eastern-nigeria
- “About the Lake.” (N.D.). Friends of Great Salt Lake. https://www.fogsl.org/about/map
- “Meet the Microenvironments.” (N.D.). Learn Genetics. Accessed via https://learn.genetics.utah.edu/content/gsl/micro/
- “Great Salt Lake wildlife.” (2021). Government of Utah Great Salt Lake Ecosystem Program. Accessed via https://wildlife.utah.gov/gslep/wildlife.html
- “Great Salt Lake.” (N.D.) Western Hemisphere Shorebird Reserve Network. Accessed via https://whsrn.org/whsrn_sites/great-salt-lake/
- “Great Salt Lake FAQ.” (2013). Natural History Museum of Utah. Accessed via https://nhmu.utah.edu/sites/default/files/attachments/Great%20Salt%20Lake%20FAQ.pdf#:~:text=o%20The%20rock%2Dfill%20causeway%20has%20had%20two,arm%20has%20become%20saltier%20than%20the%20south.
- “Solar Evaporation Ponds.” (N.D.). Compass Minerals. Accessed via https://www.compassminerals.com/who-we-are/locations/ogden-utah/
- Gavel, M., et al. (2018). “What kills Frame Lake? A precautionary tale for urban planners.” PeerJ. Accessed via https://pmc.ncbi.nlm.nih.gov/articles/PMC6004302/pdf/peerj-06-4850.pdf
- “Arsenic trioxide and underground issues at Giant Mine.” (2024). Government of Canada Crown-Indigenous Relations and Northern Affairs. Accessed via https://www.rcaanc-cirnac.gc.ca/eng/1100100027413/1617999134934
- Hashmi, N. (2025). “Aerator that could restore fish in Yellowknife’s Frame Lake turned on.” CBC North. Accessed via https://www.cbc.ca/news/canada/north/aerator-fish-frame-lake-1.7420627
- Montero-Rosado, C., et al. (2022). “Water Diversion in the Valley of Mexico Basin: An Environmental Transformation That Caused the Desiccation of Lake Texcoco.” Land. Accessed via https://www.researchgate.net/publication/359832565_Water_Diversion_in_the_Valley_of_Mexico_Basin_An_Environmental_Transformation_That_Caused_the_Desiccation_of_Lake_Texcoco
- “Sistema Lacustre Ejidos de Xochimilco y San Gregoria Atlapulco.” (2004). RAMSAR. Accessed via https://rsis.ramsar.org/ris/1363
- “Historic Centre of Mexico City and Xochimilco.” (N.D.). UNESCO. Accessed via https://whc.unesco.org/en/list/412/
- “Lake Texcoco.” (2023). Encyclopedia Britannica. Accessed via https://www.britannica.com/place/Lake-Texcoco
- “Xochimiclo.” (2025). Encyclopedia Britannica. Accessed via https://www.britannica.com/place/Xochimilco
- “Lake Texcoco, first Ecohydrology Demonstration Site in Mexico by UNESCO.” (2025). UNESCO. Accessed via https://www.unesco.org/en/articles/lake-texcoco-first-ecohydrology-demonstration-site-mexico-unesco
- “Dry Valley Tour: Part I.” (N.D.). McMurdo Dry Valleys Long Term Ecological Network. Accessed via https://mcm.lternet.edu/node/1792
- “Dry Valley Tour: Part II.” (N.D.). McMurdo Dry Valleys Long Term Ecological Network. Accessed via https://mcm.lternet.edu/node/1794
- “Dry Valley Critters.” (N.D.). McMurdo Dry Valleys Long Term Ecological Network. Accessed via https://mcm.lternet.edu/node/1856
- “Don Juan Pond.” (N.D.). McMurdo Dry Valleys Long Term Ecological Network. Accessed via https://mcm.lternet.edu/content/don-juan-pond
- “Lake Vanda, Antarctica.” (2009). NASA Visible Earth. Accessed via https://www.visibleearth.nasa.gov/images/42109/lake-vanda-antarctica/42110l
- Hawes, I.; Schwarz, A.; Sutherland, D.; Howard-Williams, C. (2003). “Aquatic ecosystems of the McMurdo Dry Valleys — the edge of survival.” Water and Atmosphere. Accessed via https://niwa.co.nz/sites/default/files/import/attachments/mcmurdo.pdf
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