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.
Permanent reversals
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 |
Temporary reversals
Intermittent temporary reversals
s often cause temporary reversals of coastal rivers.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 | |
Mississippi River | Gulf of Mexico | North America | 2005 | Storm surge from Hurricane Katrina | |
Mississippi River | Gulf of Mexico | North America | 2012 | Storm surge from Hurricane Isaac |
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 | 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 |