Colombia's Ituango Dam Crisis: Evacuation, Collapse and Lessons for Megaprojects

The B1M explains the Ituango Dam, Colombia's largest hydroelectric project, designed to supply significant electricity while stabilizing the Cocoa River valley. The video traces its ambitious construction since 2010, the problematic diversion tunnels through fractured rock, and a dramatic 2018 crisis that triggered a mass evacuation of downstream communities. It highlights how schedule pressure, financial incentives, and limited stakeholder consultation contributed to a near-catastrophic failure and long-term social and environmental costs. The film ends with a reflection on the enduring tension between mega-infrastructure ambitions and rigorous engineering practice.

Overview

The B1M presents the Ituango Dam project in Colombia, a modern, state-backed hydroelectric undertaking aimed at powering the country and reducing reliance on thermal plants. At 225 metres tall with a reservoir potentially extending up to 127 kilometres and holding 2.72 billion cubic metres of water, Ituango was envisioned as Colombia's largest hydroelectric project, capable of delivering around 17% of the nation's electricity. The project was also meant to shield the grid from shortages and blackouts that had plagued the country as its population grew from 33 million in 1990 to more than 53 million today. The dam was supposed to boost energy independence and catalyse broader infrastructure growth.

Background: Why Colombia Needed It

Colombia hosts mighty rivers and a productive Cocoa River valley that supports sugarcane and ethanol production, irrigation, and coffee. Hydropower has long been a backbone of the electricity mix, offering cheap energy relative to other sources. As the population expanded rapidly in the preceding decades, the existing grid struggled with shortages, making a large-scale hydro project strategically appealing. The Ituango project was presented as a cornerstone of those ambitions, promising flood control benefits and greater resilience against variability in rainfall and river flows.

Construction Challenges and Diversion Tunnels

Constructing the dam required diverting the Cocoa River through deep diversion tunnels cut into highly fractured rock in the Central Andes. TBMs would not fit, so workers relied on drill and blast methods, with tunnel lining, shotcrete, rock bolts, and extensive ventilation to manage geologic hazards. Groundwater and seismic activity in the region increased the risk of deformation and sudden rock movement. By 2015 the project was behind schedule, and a disruptive push to accelerate construction offered large financial incentives to the utilities company, Empresa Publica de Medellin (EPM). The pressure to deliver energy on schedule led to a hurried pace, with 24/7 operations intended to recover 18 months of delays and preserve credit. The diversion tunnels ultimately became a central vulnerability: a deformation caused a blockage, water backed up, and the main outlet through the tunnels collapsed, compromising the dry-season diversion plan and generating the crisis that followed.

In response to the breach of the river diversion, engineers raised the dam 225 metres to maintain containment and opened the spillway as a controlled outlet, a move not fully tested under real operating conditions. This partial stabilization prevented an immediate dam failure but introduced downstream disruption, including flooding of equipment housings and damage to intake components. A Dutch underwater construction specialist later waterproofed and sealed the intake structures, while new diversion tunnels were built and some of the old channels abandoned. As the project progressed, four turbines remained offline, with a target of 2027 for completion and full operation.

The 2018 Crisis: Evacuation and Aftermath

Authorities evacuated more than 25,000 people downstream, initially Puerto Valdivia and then the broader Cocoa River basin. The flooding damaged dozens of homes and essential facilities, including schools and a healthcare centre, turning what should have been a major energy milestone into a cautionary tale about the human costs of mismanaged megaprojects. Although the government gave the all-clear to return, many residents chose to stay away, and more than 400 families remained homeless. The incident exposed how modern megaprojects can rapidly destabilize social structures when safety, environmental, and community considerations are subordinated to the race to complete construction.

Context: Social, Environmental and Economic Impacts

The Ituango project sits in a region with a history of violence and displacement, including mass graves, disappearances, and large-scale population movements between 1990 and 2016. While the dam promised flood mitigation and broader energy security, critics argue that environmental impact assessments underestimated the risk to local communities and agriculture. The Cocoa River valley supports thousands of hectares of sugarcane and irrigated crops, contributing to Colombia's ethanol production and food security. Indirect beneficiaries would have included improved grid reliability and reduced reliance on expensive thermal plants, but these gains remain contested in light of the social and environmental costs incurred by the disaster and ongoing construction delays.

Lessons Learned and Looking Forward

The video emphasizes that money and political pressure cannot substitute for rigorous engineering standards, transparent consultation with local communities, or robust environmental impact analyses. The Ituango case illustrates the risks of applying aggressive project schedules to complex, geologically challenging environments and underscores the importance of independent oversight, contingency planning, and a holistic approach to risk that accounts for human life as a primary objective. The project team continues to push toward completion, with ongoing work to install the remaining turbines and to manage downstream risk as Colombia continues to pursue a large-scale energy transition.

Conclusion

Colombia's Ituango Dam story is a stark reminder of the scale and complexity of modern infrastructure. It shows how ambitious plans can deliver benefits, but also how easily those benefits can be undermined by technical, political, and social misalignments. The video frames Ituango as a powerful case study in the responsible design and management of megaprojects, energy policy, and the protection of communities in the path of progress.