28 May 2018
Another landslide at the Ituango dam site in Colombia
On 26th May 2018 a further landslide occurred at the Ituango dam site (Hidroituango) in Colombia. The slope failure led to the evacuation of the 1500 workers at the site. There were no injuries and the integrity of the dam does not seem to be threatened. The best report that I can find is in El Espectador (in Spanish of course), a translated version of which is as follows:-
Empresas Públicas de Medellín (EPM) reported that a new landslide occurred on the afternoon of this Saturday in the Ituango hydroelectric project, which has been on alert since April 28. The company reported that, due to the fact, the 1,500 workers who were working on the project were evacuated. EPM also informed that there were no workers injured as a result of the incident and that at this moment the necessary technical evaluations are being done to know when they can resume work on the project. After the collapse, the authorities made the decision to suspend vehicular traffic to and from the urban center of the Ituango municipality. Citizens who have to enter or leave the town on Sunday, May 27, presidential election day, will have to do it by boat.
Images of the landslide suggest that it was much smaller than the earlier event, and occurred on a slope above the area that had been cut. Juliana Ramirez tweeted an image of the landslide:-
The landslide was also caught on a video that has been posted to Youtube by Noticias Caracol:
Landslides associated with impounding of the lake at a large dam are not unusual – the stability of the slopes declines as the groundwater level rises. This latest slope failure is perhaps surprising in that it has occurred so high up the slope though.
This site has now suffered the initial tunnel collapse, the large landslide a few hundred metres upstream of the Ituango dam site, and now this small landslide above the works. These events continue to ask questions about the degree to which the geotechnical conditions of the site are fully understood. I am sure that will be a major theme as the dam is commissioned. In the short-term EPM are doing the right things in maintaining the evacuations, strengthening the crest of the dam and monitoring the slopes.