List of rivers that have reversed direction
A number of rivers are known to have reversed the direction of their flow, either permanently or temporarily, in response to geological activity, weather events, climate change, or direct human intervention.
|River||Original outlet||Current outlet||Continent||Date of reversal||Cause of reversal||References|
|Amazon River||Pacific Ocean||Atlantic Ocean||South America||Cretaceous period||Formation of Andes Mountains|
|Chicago River||Lake Michigan||Mississippi River||North America||1900||Construction of Chicago Sanitary and Ship Canal|
Intermittent temporary reversals
|River||Outlet||Continent||Date of reversal||Cause of reversal||References|
|Chicago River||Mississippi River||North America||2017||Storm surge|
|Mississippi River||Gulf of Mexico||North America||1812||Tectonic uplift caused by New Madrid earthquakes|
|2005||Storm surge from Hurricane Katrina|
|2012||Storm surge from Hurricane Isaac|
- These reversals represent a return to the Chicago River's original natural outlet in Lake Michigan.
- Reversals of the Chicago River have been increasing in frequency in association with global warming, and may soon occur at least once each year.
Regular temporary reversals
Rivers which act as tidal estuaries may exhibit flow reversal with the tidal cycle.
|River||Outlet||Continent||Frequency of reversal||Cause of reversal||References|
|Hudson River||Upper New York Bay||North America||semidiurnal||Tide in Upper New York Bay|
|Saint John River (Reversing Falls)||Bay of Fundy||North America||semidiurnal||Tide in the Bay of Fundy|
|Tonlé Sap River||Mekong River||Asia||annual||Monsoon flooding of the Mekong River|
- Stream capture, in which a stream or river is diverted from its own bed, and flows instead down a neighboring channel
- Borneman, Elizabeth (November 24, 2014). "Rivers that Flow Backwards". Geo Lounge. Retrieved 18 March 2019.
- "How Climate Change Is Making This River Run Backwards". EcoWatch. Natural Resources Defense Council. June 4, 2017. Retrieved 19 March 2019.
- Soniak, Matt (January 25, 2013). "Has a U.S. River Run Backwards Before?". Mental Floss. Retrieved 18 March 2019.
- "Mississippi River Flows Backwards Due to Isaac". USGS Newsroom. United States Geological Survey. August 29, 2012. Retrieved 19 March 2019.
- "The Hudson Estuary: A River That Flows Two Ways". New York State Department of Environmental Conservation. Retrieved 19 March 2019.
- "Reversing Falls". New-Brunswick.net. Retrieved 18 March 2019.
- Jennings, Ken (February 2, 2015). "Why the Tonle Sap River Is Unlike Any Other River in the World". Condé Nast Traveler. Retrieved 18 March 2019.