Earthquake Swallows River and More Weird News
First reported July 15, 2011 · Updated October 28, 2026
July 15, 2011 | Upala, Costa Rica
Residents of communities near Upala in northern Costa Rica saw something alarming after the July 12, 2011, earthquake sequence: the Guacalito River temporarily stopped flowing through part of its usual channel. The episode prompted reports that the earthquake had somehow swallowed a river. By the following day, however, water was moving again, according to contemporaneous reporting from La Nación.
The event took place near the border of Alajuela and Guanacaste provinces, where a series of earthquakes shook homes, damaged property and triggered concern about the stability of the surrounding terrain.
The river that seemed to disappear
A strong earthquake struck the Upala area at approximately 2:11 p.m. on July 12. Early seismic reports put its magnitude at 5.1, while later scientific estimates varied. The shaking was followed by additional tremors, including a widely reported event near Santa Rosa de Bagaces.
The Guacalito River’s sudden drop in flow became one of the most talked-about consequences. Residents in the Armenia and Guacalito communities approached the channel to see what had happened. The apparent disappearance was dramatic because local waterways are important for households, farms and wildlife.
On July 13, La Nación reported that water began flowing again around 12:15 p.m. The returning water was muddy, and police were concerned about the possibility of a sudden surge. The report establishes that the river did not remain permanently lost underground.
The precise physical mechanism was not established in the reporting reviewed for this article. An earthquake-related obstruction or temporary redirection is plausible, but should not be stated as a verified cause without a geological assessment.
For more on the earthquake itself, see 5.3 Earthquake in Upala Alajuela.
Why the episode attracted strange-news coverage
River flow can change abruptly when steep terrain moves or channels become blocked. An earthquake can shake loose sediment, alter an existing landslide or disrupt the path of water. Those mechanisms are familiar to geologists, but identifying the cause in any particular river requires direct observation and measurements.
At the time, other unusual natural events in Costa Rica were also circulating in news and online discussions, including claims about beaches changing shape, bubbles offshore and heightened volcanic activity. Some were described without measurements, clear locations or scientific attribution. They do not establish a nationwide pattern of extraordinary geological events.
The Upala case stands apart because the interrupted flow and subsequent return of the Guacalito River were both reported locally, with dates and places that can be checked.
What happened next
Within roughly a day of the July 12 shaking, Guacalito’s flow had resumed. The episode illustrates how a frightening eyewitness description can turn into a broader online claim even after the immediate condition changes. The lasting verified facts are the earthquake, the temporary loss of visible river flow and its return.
Questions and answers
Did an earthquake permanently swallow a Costa Rican river? No. The Guacalito River stopped flowing visibly for a period but water returned on July 13, 2011.
Where did this happen? In the Guacalito and Armenia area of Upala, northern Alajuela province.
Was the exact cause confirmed? Not by the independently reviewed reporting. A temporary blockage remains a possible explanation, not a demonstrated one.