This animation shows the results of a tailings dam failure scenario for the Quimi tailings facility at the Mirador Mine in southeastern Ecuador. The model simulates a catastrophic release of 77% of the tailings in the impoundment. The impoundment has three connected dams in a ring configuration; the longest dam, which faces the rio Quimi, is 28 meters high, and the impoundment has a total capacity of 12.1 million cubic meters of tailings.
Communities along the banks that are at higher elevation, such as the town of Tundayme, should not be inundated by this Quimi tailings dam failure. However, communities and structures along the banks of the Rio Quimi are likely to be inundated. Most of the tailings would be deposited between the Quimi impoundment and area below the town of Tundayme, with spilled tailings reaching 5 to 10 meters thick. The hazard for anyone inside or outside buildings or other structures along the rio Quimi and in or near the confluence with the rio Zamora is high. It will take about 30 minutes for the tailings to reach the Rio Zamora.
The Tundayme tailings facility has a higher dam and a much larger impoundment than the Quimi facility. A failure of the Tundayme dam would therefore have a greater impact. The dam height is roughly 30 times that of the Quimi dam, and the capacity is more than 30 times larger than the Quimi impoundment. The animation shows a catastrophic release of 77% of the tailings volume from the current known height of the dam. The simulated failure assumes that the tailings released from the Tundayme impoundment will cascade into the Quimi impoundment. Because the Tundayme dam and impoundment are much larger than the Quimi facility, the impacts of a cascading failure of both dams are similar to those of a failure of the Tundayme dam alone.
The flows from the combined Tundayme-Quimi failure will likely destroy bridges and buildings and other infrastructure within the flood zone. Tailings would be deposited to depths of 30 meters or more down the Rio Quimi valley to the confluence with the Rio Zamora, and tailings thicknesses of 10 meters in the rio Zamora will extend 10 kilometers downstream and 5 kilometers upstream of the confluence with the Rio Quimi. Although the predicted inundation from a cascading failure of both dams is extensive, potential future impacts from a failure of the Tundayme dam would be even greater because the dam height is planned to be expanded to 320 meters, making it the highest tailings dam in the world.