Chaglla Hydroelectric Power Plant
One of the largest hydroelectric generation facilities developed in Peru, with an installed capacity of 460 MW.
Project Overview
The Chaglla Hydroelectric Power Plant is one of the largest hydroelectric generation facilities developed in Peru, with an installed capacity of 460 MW.
Located in the Huánuco region within the Peruvian Amazon, the project captures and stores water from the Huallaga River through a 203-meter-high rockfill dam and conveys the stored water through a 14.3-kilometer headrace tunnel to an underground powerhouse housing two 230 MW generating units.
The project involved the construction of large-scale underground works, hydraulic structures, access roads, material extraction systems, and power generation infrastructure in a remote location with limited existing infrastructure.
Challenge
The Chaglla Hydroelectric Project presented significant engineering, logistics, and construction management challenges from the earliest stages of development.
Remote Site Development
One of the first major challenges was simply reaching the project location. The site was located in a largely undeveloped area with no existing infrastructure capable of supporting a project of this magnitude. Before major construction activities could begin, engineering studies had to be completed to design and construct approximately 10 kilometers of access roads through difficult terrain. These access works were executed progressively using a reduced fleet of equipment specifically planned for the initial development phase.
Construction of a 203-Meter-High Rockfill Dam
The project required the construction of a 203-meter-high rockfill dam, one of the largest structures of its kind in the region. The success of the dam depended on securing a continuous and reliable supply of millions of cubic meters of rockfill material while maintaining strict construction schedules and quality requirements.
Material Supply Constraints
A critical challenge emerged during the planning and execution of the rockfill embankment. Existing quarries and river deposits alone were insufficient to provide the volume of material required for dam construction. To overcome this limitation, a comprehensive material sourcing strategy was developed that integrated four independent supply sources: existing nearby quarries, riverbed extraction areas, material generated from tunnel excavation activities, and rock obtained from systematic bench excavations in surrounding hillsides through controlled surface blasting operations. Managing these multiple sources simultaneously required sophisticated planning, logistics coordination, and production monitoring.
Underground Excavation Complexity
The project incorporated a 14.3-kilometer headrace tunnel excavated using conventional Drill & Blast methods. In addition, large underground caverns were excavated to house the powerhouse and associated facilities. The underground works required precise sequencing, geological monitoring, ventilation management, and production control to maintain progress and safety throughout construction.
High Hydraulic Head Infrastructure
Water was conveyed from the reservoir through the headrace tunnel and delivered to the underground powerhouse with an approximate vertical drop of 380 meters. This required highly specialized hydraulic and underground engineering solutions to safely manage the significant energy generated by the system.
GMCi Approach
GMCi leadership participated in planning, monitoring, project controls, and construction performance management activities supporting successful project execution. Key contributions included
Integrated Project Planning
Development and monitoring of master schedules. Coordination of multiple construction fronts. Sequencing of dam, tunnel, underground works, and infrastructure activities. Milestone tracking and schedule forecasting.
Construction Monitoring & Project Controls
Progress measurement and reporting. Performance tracking across major work packages. Productivity monitoring. Forecast analysis and recovery planning.
Material Supply Management Support
Monitoring production from multiple material sources. Tracking excavation and material availability. Supporting construction sequencing to ensure uninterrupted embankment production.
Risk Management
Identification of schedule-critical activities. Monitoring underground excavation performance. Evaluation of logistics and material supply risks. Support for proactive mitigation strategies.
Executive Reporting
Development of project performance reports. Progress dashboards. Schedule visibility and management reporting. Decision-support information for project leadership.
Results
Despite its remote location and significant engineering complexity, the project achieved major construction milestones and was successfully delivered as a strategic energy infrastructure asset.
Major Accomplishments
- Construction of a 203-meter-high rockfill dam
- Successful excavation of a 14.3-kilometer headrace tunnel
- Completion of large underground caverns for powerhouse facilities
- Installation of two 230 MW generating units
- Development of critical access infrastructure in previously undeveloped terrain
- Successful implementation of a multi-source material supply strategy supporting dam construction
- Safe execution of extensive underground excavation works
Long-Term Impact
- 460 MW of installed renewable energy generation capacity
- Increased reliability of Peru's national power grid
- Long-term support for economic development and industrial growth
- Creation of a strategic infrastructure asset supporting national energy security
Construction Performance Highlights
- Complex underground works completed using Drill & Blast excavation methods
- Successful management of multiple concurrent construction fronts
- Continuous material supply maintained through four independent sourcing systems
- Effective coordination of dam, tunnel, underground, and infrastructure construction activities