Is There Any River That Doesn't Meet a Sea or an Ocean?

Yes, there are rivers that do not flow into a sea or ocean. These rivers are often referred to as endorheic rivers. An endorheic basin is a closed drainage basin that retains water and does not allow it to flow to the sea. A well-known example is the Jordan River, which flows into the Dead Sea. The Dead Sea, a salt lake, is bordered by Jordan to the east and Israel and Palestine to the west and has no outlet to the ocean. Another example is the Zambezi River, which flows into the Zambezi Delta and does not reach the ocean. However, it is important to note that most major rivers eventually find their way to the sea, and many endorheic rivers are smaller or less well-known.

Unique Hydrological Systems: Endorheic Rivers in Australia

In Australia, a number of rivers flow into Kati Thanda, also known as Lake Eyre. While there are plenty of rivers connected to Lake Eyre, it takes a lot of rain to get them flowing and actually filling the lake. Main rivers include the Diamantina River, Cooper Creek, Georgina River, Warburton, and Macumba. When flooded, Lake Eyre supports major breeding events of the congregatory Banded Stilt and Australian Pelican and more than 1% of the global populations of the congregatory Silver Gull, Red-necked Avocet, Sharp-tailed Sandpiper, Red-necked Stint, and Caspian Tern.

Endorheic Rivers in Africa: The Okavango River

I know of a river in Botswana, Africa, the Okavango River, which ends in the Okavango Delta in land, not in a sea or lake. The Okavango Delta is a shallow delta that forms in the rainy season and dries up in the dry season. There could be others. In the Earth's past, there is evidence of water bodies that could be interpreted as rivers, lakes, and cascades that did not reach a sea. Today, these water bodies are often part of deserts.

Desert Sinks and the Example of the Humboldt River

The Humboldt River in the state of Nevada, United States, essentially dries up after traveling for about 380 miles, or 611 kilometers. It is not the only river to disappear into a sink; the American continent, for instance, has many intermittent streams. This usually happens in a desert environment such as that found in much of inland Australia or the American Great Basin, where the Humboldt River is the area’s third largest river.

The Humboldt River is one of the better-known rivers to end in a desert sink because it famously became a route for settlers to follow heading west until it disappeared. In spite of its disappearing act, the Humboldt is home to endemic species of fish, and in recent years beavers have recolonized the river, building dams that hold water for most or all of the year and extend the river toward permanent status. Riparian species of trees and aquatic plants also flourish in and along the banks of the river, especially in areas of more reliable water sustainability. Since its main source of water is snowmelt, its flow is highly variable, and the Humboldt is also fed by springs, the strength of which depends upon the desert water table, also highly variable.

Exploring Endorheic Rivers

Endorheic rivers present a unique set of conditions, influencing both the local ecosystem and the human populations that depend on them. From the unique flora and fauna found in and around these rivers to the challenges and opportunities they present, understanding these hydrological systems is crucial for sustainable water management and conservation efforts.