The Coca Codo Sinclair Hydroelectric Power Plant, built by the Chinese company SinoHydro and described as the largest engineering work in Ecuador’s history, is in grave danger. A series of structural defects, the accumulation of sediments due to the lack of floodgates, as well as a process of regressive erosion, are pushing power generation and distribution to a halt, Ecuadorian newspaper El Universo reported.
In mid-June, representatives of Ecuador’s Power Corporation (CELEC) and the U.S. Army Corps of Engineers (USACE) met in Quito to develop effective solutions to stop the advance of regressive erosion, which threaten the Coca Codo Sinclair power plant.
USACE personnel made their first technical visit to the hydroelectric plant back in 2021 and have since then worked with CELEC, at Ecuador’s request, toward a solution to mitigate the river’s regressive erosion and protect the infrastructure. More recently, USACE members have been working to implement emergency measures in at-risk areas and expanding monitoring to predict and reduce power outages, the U.S. Embassy in Quito indicated.
“The U.S. Army Corps of Engineers brought in a variety of outside government agencies to […] help better understand the Coca River sedimentation challenges,” Adriel McConnell, USACE Latin America Project Manager, said on the Embassy’s X account. “Our goal is to better understand how to stabilize this new river profile, between the collapse and the catchment itself, to maintain the long-term reliability of the power system.”
In a bit more than three years, between June 2020 and January 2024, this erosion caused the loss of 508 hectares of native forest, and the pace of deforestation is only increasing, Washington-based nongovernmental organization Conservación Amazónica reported.
The greatest geological impact happened in 2021, with the disappearance of the San Rafael Waterfall, 20 kilometers from the catchment area that diverts the flow to the hydroelectric plant. The The disappearance of the waterfall and the river changed course caused the accelerated erosion upstream which, in turn, created landslides and the collapse of the river walls, Ecuadorian television network Teleamazonas reported.
“The problem started with failure to consider dragging of the thick sediments, of those quite large stones of more than 20 centimeters. This is what filled the reservoir, which should not have existed, but formed,” Dr. Carolina Bernal, a research professor at Ecuador’s National Polytechnic School, told Diálogo on July 20. “The lower part was filled with all these very thick sediments and now in the upper part the fine sediments are forming islands, with trees up to four or five meters high.”
Construction of the hydroelectric plant began in July 2010 and was completed in November 2016, according to Ecuador’s Ministry of Energy and Mines. Within two years of its inauguration, the first construction defects appeared: 7,648 cracks in the turbines. The area also presented the first obstructions by sediment, sand, and tree branches, The New York Times reported in 2018.
“If sediment gets into the turbines, they get damaged. At the speeds at which they spin, the sediment destroys them,” Bernal added. “When the regressive erosion reaches the catchment area, the riverbed will deepen. Then the collector tunnel and the water will no longer be at the same level. The water will be lower and will not be able to enter.”
The regressive erosion of the river is advancing rapidly in the direction of the plant’s water storage, also endangering the oil infrastructure in the area and the E45 highway, Ecuadorian newspaper El Comercio reported. The Coca River Executing Commission, in its daily monitoring report of July 9, confirmed the above and said that the zone is now at high risk.
“We are only 6.8 km from critical infrastructure. If urgent decisions are not taken, we will face massive blackouts in the country,” Dr. Inti Grungberg, an Ecuadorian environmentalist and scientist, told digital newspaper Ecuador en Vivo. “It is crucial that the government act immediately to solve this problem, before it’s too late.”
On July 2, the power plant had to shut down due to a new increase in sediment, the Coca Codo Sinclair Business Unit said via X. To avoid a generalized blackout, it started buying energy from Colombia.
One of the problems that could paralyze this hydroelectric power plant forever are the thousands of cracks in the powerhouse water distributors, local media Primicias reported on June 30. That became an international claim of the Ecuadorian Electric Corporation against the Chinese company SinoHydro. Ecuador’s Office of the Attorney General has also launched an investigation against several officials for possible bribes.
“The regressive erosion between the disappeared San Rafael Waterfall and downstream is eating up the Coca River valley,” Bernal said. “This is causing the destruction of the oil transportation system, the country’s main export product. Roads are also destroyed, and populations are isolated, forcing internal migration.”
Among Ecuador’s options to protect the Coca Codo Sinclair is the creation of a permeable dam together with USACE, which was slated to begin in mid-August, CELEC said via X.
