Colombian authorities activated emergency measures on Thursday after a sinkhole was discovered near the troubled 2.4-GW Ituango hydro project, Bnamericas reports.
Workers identified a 40-m-deep subterranean cavity while drilling to check the ground’s stability ahead of the planned closure of the project’s turbine rooms, according to local officials.
Antioquia department governor Luis Perez said project owner EPM had been given 72 hours to present a report outlining risks to local communities and consequences for the project’s future. He said new flood alerts were issued for communities downstream from the project along the Cauca river in northwestern Colombia.
“What I would recommend to the [engineers] is to avoid situations that could cause the sinkhole to grow,” Perez told reporters. “We became aware of the situation yesterday and decisions were taken after talks involving the president [Ivan Duque] and the [Medellin] mayor [Federico Gutierrez].”
EPM said its monitoring systems had not detected unusual land movements or water filtrations.
The company had planned to close the turbine rooms’ floodgates within weeks, describing the move as a major milestone in its bid to save the project. The rooms — which contain Ituango’s key machinery and equipment — were purposefully flooded last May to prevent the dam from bursting its banks.
Construction work at Ituango was halted last April after serious structural damage prompted fears of catastrophic flooding.
Located about 170 km northeast of Medellin, Ituango is the country’s largest infrastructure project in investment terms. The facility will supply more than 17% of Colombia’s electricity when fully operational.
EPM has said the plant’s operational startup will be postponed by at least three years to December 2021 in a best-case scenario.
It forecasts the total cost of the emergency will reach US$2.2 billion, including US$1.3 billion in lost energy sales, US$630 million in repair works and US$314 million in contingency expenses. The project had been budgeted at US$4 billion before the construction problems began.
In November 2018, HydroWorld reported EPM had secured a US$314 million credit line from Bancolombia, available for two years and only to be used if necessary to stabilize cash flow, EMP said.