Canals, Tunnels and Penstocks, Environmental, Latin America

Project Update: Work to revive 2.4-GW Ituango hydro project

EPM in Colombia has provided an update on its work to revive the 2.4-GW Ituango hydro project after a series of landslides prompted the government to declare a state of emergency in May.

In information sent to Superfinanciera, Colombia’s financial market regulator, EPM said work continues on heightening the dam wall, which has reached 418 m above sea level downstream from the plant and 403 m upstream and is expected to reach a final height of 435 m in the first quarter of 2019. Additionally, cement injections have been completed to strengthen the contact between the massif and dam. And work is advancing to install a concrete and bentonite screen to guarantee the dam’s impermeability.

EPM is working tirelessly on the recovery of the Ituango hydroelectric project, a country project that will supply 17% of the energy that Colombia needs to continue growing [while] contributing to the quality of life of millions of people,” the company said.

Next up are plans to close the turbine rooms, which were opened in May to prevent “catastrophic flooding.” Timing here depends on rainfall, the behavior of the dam following installation of the above-mentioned screen and the progress of work to unblock a tunnel and auxiliary spillway gallery.

Other efforts under way are concentrated on completing concrete coating to reinforce the intermediate gallery tunnel, depressurize the chamber, empty infiltrated waters and reinforce existing plugs. Once plug reinforcement is complete, the gates chamber of the auxiliary diversion spillway will be evaluated to determine if they can be closed.

Cement injection tests are being carried out to determine the effectiveness of the initial consolidation treatment of the gravel inside the right diversion tunnel, with an aim to proceed with its pre-plugging. In turn, in the left diversion tunnel downstream of the final plug, the infiltration water is being pumped. The entrances of the diversion tunnels are currently blocked due to a collapse that occurred in late April.

EPM is building an access road to the upper part of the dam, to allow the start of treatment and stabilization of the landslide by means of controlled excavations.