Last Friday, the National Electricity Operator CENACE of Ecuador announced that due to the increase in flows in Coke Elbow Sinclair, sediments were generated again, causing blackouts in several areas of the country. However, after noon on June 21, it was reported that the hydroelectric plant was operational and power was being restored.
This is not the first time that sediments at Coca Codo Sinclair have caused power supply interruptions. On June 16, after intense rains that caused landslides and affected roads and towns, the Minister of Energy, Roberto Luque, explained that the rains increased the flows and generated high sediment levels in the hydroelectric plant, which was out of operation since 07:00. Other power plants in Ecuador were also affected by the rainfall. An hour later, they managed to start two Coca Codo Sinclair turbines and the blackouts were cancelled.
Likewise, on May 22, the same problem was reported at the hydroelectric plant, built by a Chinese company. According to Luque, “a sudden increase in sediment from the Coca Codo Sinclair catchment forced the gates to be closed, leaving the plant without generating electricity.”
The Coca Codo Sinclair hydroelectric project was created during the government of former President Rafael Correa and was presented as the “largest in the history of Ecuador.” The useful life of the hydroelectric plant was estimated at 50 years, but Dr. Carolina Bernal, a research professor at the National Polytechnic School, who has studied the Coca River since 2004, spoke with Infobae and explained that the useful life, in the best case, will be 15 years.
Concerns about the status of the megaproject are not new. In July 2022, a confidential report from the Ecuadorian Electricity Corporation (CELEC EP) to which Infobae had access reveals that since 2012 the chinese company Sinohydroin charge of the Coca Codo Sinclair hydroelectric project in Ecuador, hid the fact that the turbine distributors in the plant’s power house had around 8,000 cracks. But to the fissures of the plant are also added the problems generated by the regressive erosion of the Coca River, a natural phenomenon that, according to Bernal, at the beginning of this month: “In the particular case of the Coca River, having built a hydroelectric plant, it does dramatically altered the flow or transit of sediments and liquid flow (water). “Erosion accelerated exponentially while the phenomenon of sedimentation, which is a phenomenon that should never have existed in an area like that, skyrocketed.”
In January 2024, two scientists from the United States Geological Survey (USGS) visited Ecuador for the second time to advise authorities on the natural disaster of regressive erosion which happens in the Coca River, located in the Ecuadorian Amazon, whose waters allow the Coca Codo Sinclair to operate. Both the USGS, the US Army Corps of Engineers (USACE) and other federal agencies are accompanying the Ecuadorian government to find strategies to manage sediment and erosion in the Coca River basin, especially after the collapse of the San Rafael waterfall in February 2020, which as a result of the phenomenon formed a natural arch, which a year later also collapsed.
Seven researchers from US federal agencies and the Ecuadorian Electricity Corporation published a scientific article in February of this year on what is happening in the Coca River and concluded that: “The geomorphological adjustment of the Coca River represents a highly unusual natural disaster that “It threatens life (useful), property, main infrastructure and energy security, as it compromises oil pipelines and the largest hydroelectric facility in Ecuador.”
In interview with Infobae, Adriel McConnell, USACE program manager for water resources in Latin America, explained that American researchers and scientists have worked closely with the Coca River Commission since 2020 to support their efforts in understanding and controlling erosion: “They have a leading role and “We are a supporter, helping to provide guidance and advice while they advance in making decisions to implement erosion control projects,” he indicated. The agreement for technical services was signed for five years, but McConnell indicated that this “will last as long as necessary to achieve the objectives of the Coca River Commission.”
The USACE project manager explained that they still do not have a timeline that indicates possible solutions to contain the phenomenon and protect the hydroelectric plant because at this moment, researchers are in the data collection phase: “We have great scientists investigating these schedules trying to formulate an early and a late arrival; Much of that depends on hydrological conditions and how much rain occurs in the area. It is a very new and unprecedented challenge worldwide.”, he assured.
This support, as McConnell recognized, is extremely necessary for Ecuador because the erosion front – that is, the area where the phenomenon occurs – is a significant threat, and the efforts of scientists and researchers are focused on preventing it from undermining the structure of the hydroelectric catchment: “Our working theory does not focus so much on the damage to the structure itself, but rather on an undermining of the catchment. So if the erosion front reaches the catchment, it further undermines the structure and does not allow water to be diverted towards the tunnel infrastructure,” he explained.
The Coca Codo Sinclair is not a conventional hydroelectric plant, like those that create large flooded reservoirs. Instead, it uses a tunnel to bring the river into a small reservoir from where it falls about 200 meters to the power house, where electricity is generated, and then the water flows out. When building the catchment, the approach channel forces the river to enter through the tunnel and transports the sediment it carries with it.
In this scenario, McConnell noted that efforts are focused on the erosion front between the catchment and the place where the waterfall collapsed, sediment deposition downstream and sediment monitoring upstream: “We are working closely to develop a sediment monitoring plan and then develop solutions that can help improve the reliability of the infrastructure,” he assured.
When asked about the impact of the sediments at Coca Codo Sinclair and the blackouts in Ecuador, the US official explained that the drought in the region, attributed to El Niño, has been a more significant factor in Ecuador’s energy challenges than the sedimentation problems: “The lack of rain to recharge the reservoirs is more the dominant challenge that countries, even outside Ecuador, have been having for the energy crisis.” This crisis is linked to climate change, McConnell said: “It is not our opinion that the current sediment has impacted the energy challenges facing Ecuador at this time; “I would attribute that more to the climate challenges in the area over the last 18 months.”
