1 June 2023

El Molino: a valley-blocking landslide breach event in Colombia

Posted by Dave Petley

El Molino: a valley-blocking landslide breach event in Colombia

Back in November I posted twice (here and here) about the very large, valley blocking landslide at El Molino in Colombia on 10 November 2022, which is located at [7.949, -73.025]. Five people were killed and 28 families were rendered homeless.  Based on Planet imagery, I noted that “there is concern about the damming of the river as well as about the potential for a further landslide.  A small lake has developed.”

Yesterday, Helbert Garcia-Delgado tweeted to that the lake had breached, creating a debris flow:

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The video in the second tweet shows the aftermath of the resultant landslide.  This is an area that is very difficult to image with satellites as cloud is very common, but fortunately Planet captured an image on 31 May 2023 that is mostly cloud free.  So first, this is an image from 18 May 2023, showing the aftermath of the landslide and with the lake, located on the southern side margin of the landslide, intact:-

The El Molino landslide before the breach of the lake, as captured on 18 May 2023.

The El Molino landslide before the breach of the lake, as captured on 18 May 2023. Image copyright Planet, used with permission.

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And here is the same site in an image dated 31 May 2023. showing the aftermath of the breach event:-

The El Molino landslide after the breach of the lake, as captured on 31 May 2023. Image copyright Planet, used with permission.

The El Molino landslide after the breach of the lake, as captured on 31 May 2023. Image copyright Planet, used with permission.

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The image clearly shows that the lake has indeed breached and that most of the water has escaped, leaving a small muddy pool.  The slider below should allow you to compare the two images, including the changes in morphology of the landslide caused by the debris flow:

The El Molino landslide before the breach of the lake, as captured on 18 May 2023.The El Molino landslide after the breach of the lake, as captured on 31 May 2023. Image copyright Planet, used with permission.

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La Opinion has a news report about the debris flow, which indicates that there has been extensive damage to farmland, houses and a bridge in the municipalities of Ábrego and Villa Caro.

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Reference and acknowledgement

Planet Team (2023). Planet Application Program Interface: In Space for Life on Earth. San Francisco, CA. https://www.planet.com/