As we reported last week, a catastrophic dam failure at the Samarco iron mine in southern Brazil killed 11 and left 12 missing, buried the town of Bento Rodrigues under millions of cubic meters of toxic mine waste, and left thousands across the region without clean water. Troublingly, the threat of further flooding persists as heavy rains move in and mine operators BHB Billiton and Vale SA scramble to shore up the remaining impoundments.
DigitalGlobe and Google Earth have acquired high resolution imagery of the aftermath, and there are several issues of which mine workers, downstream residents, and emergency responders need to be mindful. First of all, the Santarem impoundment immediately downstream from the failed dam did not break in the initial deluge, though it could very well have been damaged by the 40 million cubic meters of water and mine waste that poured down from Fundao. In the image below you can see that Santarem Dam is still intact, evidenced by visible spillway, but we don’t know whether or not the dam’s structural integrity has been compromised by stress and erosion.
To the southwest of the failed Fundao dam is the Germano Dam, Samarco’s oldest and largest tailings impoundment. Reportedly this dam is drier and more stable than Santarem and Fundao, but all told the mine operator is mobilizing 500,000 cubic meters of rock to shore up both remaining dams. Reuters reports the repairs could take from 45 to 90 days, meanwhile the regional weather forecasts call for thunderstorms for the next 10 days. Below is the surviving Germano Dam (bottom left) and the failed Fundao Dam (center).
The devastation is not just local, it extends far downstream. At the far eastern edge of DigitalGlobe’s recent acquisition, 40 km away as-the-crow-flies, a small farm/compound was partially wiped out by the flood of toxic red mud. You can see a bridge wiped out, the floodplain inundated, and multiple structures erased by the force of the flash flood.
Image Credit: DigitalGlobe/Google Earth Outreach
To put this disaster in perspective, current estimates put the volume of the flood so far at 40 million cubic meters of mud, debris, and toxic waste. That makes this spill 2.6x larger than the infamous Johnstown Flood which killed over 2,200 in Pennsylvania back in 1889.
We urge everyone living and working in the area and downstream to exercise extreme caution. The company reports they are monitoring the surviving dams with “radar, lasers, and drones,” but as the last image shows, the impact of another spill could be deadly even miles away from Bento Rodrigues.