Monsoon rain caused a hydroelectric dam to collapse in Laos on 23 July. Flood waters inundated six villages in Attapeu province and left more than 6000 homeless and hundreds unaccounted for.

The Xe-Pian Xe-Namnoy dam in the southern-most part of the country was under construction at the time of the disaster and was expected to be finished next year. It has been reported that the collapse of the dam - specifically a subsidiary dam called "Saddle Dam D" - released 5 billion cubic metres of water which destroyed hundreds of homes in the province and has already claimed several lives.

Affected residents are being evacuated to emergency shelters.

Related News and Resources

• Floods in Laos - Reports and Infographics (reliefweb)
• Impact Report for Floods in Laos (GDACS)
• Flash Floods and Dam Emergency: Daily Map of 25 July (ERCC)
• BBC reports on Flooding in Laos (BBC)
• Laos dam collapse: View of flooded villages – Video (Guardian)
• Sentinel-1 maps flash floods in Laos (ESA)
• Xe-Namnoy lake dam failure (CESBIO)
• Live Map: Floods in Laos (UNOSAT)
• JRC analysis assists response to Laos dam collapse (EU Science Hub)

Satellite detected water extent as of 30 July 2018 over Samakkhixay District, Attapeu Province, Laos

Source: KOMPSAT-5

Acquired: 30/07/2018

Copyright: KOMPSAT-5 © KARI (2018)
Map produced by UNITAR/UNOSAT

Product: link

Satellite detected water extent as of 27 July 2018 over Sanamxay District, Attapeu Province, Laos

Source: TerraSAR-X

Acquired: 27/07/2018

Copyright: TerraSAR-X © DLR e. V. 2018, Distribution: Airbus DS Geo GmbH
Map produced by UNITAR/UNOSAT

Product: link

Potentially affected villages along Vang Ngao River and Xe Kong River, Laos

Download the full report

Source: Sentinel-1

Acquired: 25/07/2018 & 29/07/2018

Copyright: Sentinel-1 © Copernicus Sentinel data (2018)
Report produced by UNITAR/UNOSAT

Product: link

Time series: Evolution satellite detected water extent over Sanamxay District, Laos

Source: Sentinel-1

Acquired: 13/07/2018, 25/07/2018 & 29/07/2018

Copyright: Sentinel-1 © Copernicus Sentinel data (2018)
Map produced by UNITAR/UNOSAT

Product: link

Time series: Evolution flood satellite detected waters, Laos

Source: Sentinel-1

Acquired: 13/07/2018, 25/07/2018 & 29/07/2018

Copyright: Sentinel-1 © Copernicus Sentinel data (2018)
Map produced by UNITAR/UNOSAT

Product: link

Overview and potentially flooded areas after collapse of the Xe-Namnoy dam

Download the full report

Source: Sentinel-1

Acquired: Pre-disaster: 13/07/2018
Post-disaster: 25/07/2018

Copyright: Sentinel-1 © Copernicus Sentinel data (2018)
Report produced by UNITAR/UNOSAT

Product: link

Flooding impact map of the dam collapse in Laos

Source: Sentinel-1

Acquired: 25/07/2018

Copyright: © Contains modified Copernicus Sentinel data (2018)
Map produced by ADPC

Product: link

Flooding impact map of the dam collapse in Laos

Source: ALOS-2

Acquired: 25/07/2018

Copyright: © JAXA (2018)
Map produced by ADPC

Product: link

Evolution satellite detected water extent over Sanamxay District, Attapeu Province, Lao People Democratic Republic

Source: RADARSAT-2

Acquired: Pre-Disaster: 10/07/2018
Post-Disaster: 24/07/2018

Copyright: RADARSAT-2 Data and Products © Maxar Technologies Ltd. (2018) - All Rights Reserved. RADARSAT is an official trademark of the Canadian Space Agency.
Map produced by UNITAR / UNOSAT

Product: link

Satellite detected water extent over Sanamxay District, Attapeu Province, Lao People Democratic Republic

Source: RADARSAT-2

Acquired: 24/07/2018

Copyright: RADARSAT-2 Data and Products © Maxar Technologies Ltd. (2018) - All Rights Reserved. RADARSAT is an official trademark of the Canadian Space Agency.
Map produced by UNITAR / UNOSAT

Product: link

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